0.6.1

.gitignore

@@ -18,7 +18,12 @@ data.json
 
 # This plugin
 
+## Files are copied here on `pnpm run build`.
+/dist/
+
+## Sym-linked to the plugin's folder in the dev/test vault. Files are copied here `pnpm run dev`.
+## Git stores symlinks as a special file containing the target path string, not as a directory. So the gitignore rule needs to match a file, not a directory pattern.
+dev-vault
+
 main.js
 styles.css
-
-/dist/

README.md

@@ -90,6 +90,8 @@ id: card2
 ```
 ````
 
+There are commands that let you insert these declarations without typing in the [Command palette](https://help.obsidian.md/plugins/command-palette).
+
 > [!NOTE]
 >
 > The card declaration format is plain YAML (same as Obsidian [properties](https://help.obsidian.md/properties#Property+format)) so the YAML specification has to be adhered to. For example, there must be a space between the colon and the value.

esbuild.config.mjs

@@ -1,6 +1,7 @@
 import builtins from "builtin-modules";
 import esbuild from "esbuild";
 import fs from "fs";
+import path from "path";
 import process from "process";
 
 const banner =
@@ -11,7 +12,9 @@ if you want to view the source, please visit the github repository of this plugi
 `;
 
 const prod = (process.argv[2] === "production");
-const outdir = prod ? "dist" : ".";
+const outdir = prod ? "dist" : "dev-vault";
+
+fs.copyFileSync("manifest.json", path.join(outdir, "manifest.json"));
 
 const context = await esbuild.context({
 	banner: {
@@ -39,6 +42,7 @@ const context = await esbuild.context({
 		"@lezer/lr",
 		...builtins],
 	format: "cjs",
+	// Runtime of min supported Obsidian version 1.8.2, see manifest.json
 	target: "es2022",
 	logLevel: "info",
 	sourcemap: prod ? false : "inline",
@@ -52,7 +56,6 @@ const context = await esbuild.context({
 
 if (prod) {
 	await context.rebuild();
-	fs.copyFileSync("manifest.json", "dist/manifest.json");
 	process.exit(0);
 } else {
 	await context.watch();

eslint.config.js

@@ -32,10 +32,9 @@ export default defineConfig(
 		languageOptions: {
 			parser: tseslint.parser,
 			parserOptions: {
-				project: "./tsconfig.json",
+				projectService: true,
-				projectService: "true",
 				sourceType: "module",
-				ecmaVersion: "latest",
+				ecmaVersion: 2022,
 			},
 			globals: {
 				...globals.browser,
@@ -46,22 +45,34 @@ export default defineConfig(
 			}
 		},
 		rules: {
+			// You should always have "no-unused-vars": "off" alongside @typescript-eslint/no-unused-vars,
+			// https://typescript-eslint.io/rules/no-unused-vars/
 			"no-unused-vars": "off",
-			"@typescript-eslint/no-unused-vars": ["warn", {
+			"@typescript-eslint/no-unused-vars": ["error", {
-				args: "none"
+			    "args": "all",
+			    "argsIgnorePattern": "^_",
+			    "caughtErrors": "all",
+			    "caughtErrorsIgnorePattern": "^_",
+			    "destructuredArrayIgnorePattern": "^_",
+			    "varsIgnorePattern": "^_",
+			    "ignoreRestSiblings": true,
 			}],
+
+			//
 			"@typescript-eslint/ban-ts-comment": ["error", {
 				"ts-expect-error": false,
 				"ts-ignore": true,
 				"ts-nocheck": true,
 				"ts-check": true,
 			}],
+
 			"no-prototype-builtins": "off",
 			"@typescript-eslint/no-empty-function": "off",
 			"@typescript-eslint/no-unnecessary-condition": ["warn", {
 				// https://typescript-eslint.io/rules/no-unnecessary-condition/#only-allowed-literals
 				"allowConstantLoopConditions": "only-allowed-literals"
 			}],
+			"@typescript-eslint/switch-exhaustiveness-check": "error",
 		},
 	},
 );

manifest.json

@@ -1,8 +1,8 @@
 {
 	"id": "come-through",
 	"name": "Come Through",
-	"version": "0.6.0",
+	"version": "0.6.1",
-	"minAppVersion": "1.8.0",
+	"minAppVersion": "1.8.2",
 	"description": "Drill flashcards using spaced repetition.",
 	"author": "mntno",
 	"authorUrl": "https://github.com/mntno",

package.json

@@ -4,28 +4,29 @@
 	"description": "Drill flashcards using spaced repetition.",
 	"main": "main.js",
 	"scripts": {
+		"lint": "pnpm eslint .",
 		"dev": "node esbuild.config.mjs",
-		"build": "tsc -noEmit -skipLibCheck && node esbuild.config.mjs production",
+		"build": "(pnpm eslint . || true) && tsc -noEmit -skipLibCheck && node esbuild.config.mjs production",
 		"version": "node version-bump.mjs && git add manifest.json versions.json"
 	},
 	"keywords": [],
 	"author": "mntno",
 	"license": "MIT",
 	"devDependencies": {
-		"@eslint/js": "^9.37.0",
+		"@eslint/js": "^9.39.4",
-		"@types/node": "24.6.2",
+		"@types/node": "25.6.0",
-		"builtin-modules": "5.0.0",
+		"builtin-modules": "5.1.0",
-		"esbuild": "^0.25.10",
+		"esbuild": "^0.28.0",
-		"eslint": "^9.37.0",
+		"eslint": "^9.39.4",
-		"eslint-plugin-obsidianmd": "^0.1.4",
+		"eslint-plugin-obsidianmd": "^0.1.9",
 		"fast-equals": "5.2.2",
-		"globals": "16.4.0",
+		"globals": "17.5.0",
 		"luxon": "3.7.2",
 		"obsidian": "latest",
 		"ts-fsrs": "5.2.1",
 		"tslib": "^2.8.1",
-		"typescript": "^5.9.3",
+		"typescript": "^6.0.2",
-		"typescript-eslint": "^8.46.1"
+		"typescript-eslint": "^8.58.1"
 	},
 	"type": "module",
 	"pnpm": {

src/ContentParser.ts

@@ -1,11 +1,11 @@
-import { CardDeclarationAssistant, IDScope } from "declarations/CardDeclaration";
+import { CardID, FullID, NoteID } from "#/data/FullID";
-import { Declaration } from "declarations/Declaration";
+import { DeclarationConstants } from "#/declarations/constants";
-import { DeclarationParser } from "declarations/DeclarationParser";
+import { DeclarationParser } from "#/declarations/DeclarationParser";
-import { FullSectionRange, SectionRange } from "utils/obs/FileParser";
+import { IDScope } from "#/declarations/ExplicitDeclaration";
-import { CardID, FullID, NoteID } from "data/FullID";
+import { asNoteID, fullIDFromDeclaration } from "#/TypeAssistant";
+import { UnexpectedUndefinedError } from "#/utils/errors";
+import { FullSectionRange, SectionRange } from "#/utils/obs/FileParser";
 import { App, CachedMetadata, HeadingCache, SectionCache, TFile } from "obsidian";
-import { asNoteID, fullIDFromDeclaration } from "TypeAssistant";
-import { UnexpectedUndefinedError } from "utils/errors";
 
 /**
 	* The result of attempting to retrieve the content of a particular {@link FullID}.
@@ -127,14 +127,16 @@ export class ContentParser extends DeclarationParser {
 		const predicate: PopulationPredicate = {
 			iterationFilter: (idContentInfo) => {
 
-				// For unique ids. If also filtering on noteID, then only this file will be looked at,
+				switch (idContentInfo.scope) {
-				// while the other side is in another file and thus won't be found.
+					case IDScope.Unique:
-				if (idContentInfo.scope == IDScope.UNIQUE)
+						// For unique ids. If also filtering on noteID, then only this file will be looked at,
-					return idContentInfo.id.isCardEqual(id);
+						// while the other side is in another file and thus won't be found.
+						return idContentInfo.id.isCardEqual(id);
 
-				// Should work for file-scoped IDs.
+					case IDScope.Note:
-				if (idContentInfo.scope == IDScope.NOTE)
+						// Should work for file-scoped IDs.
-					return idContentInfo.id.isEqual(id, true);
+						return idContentInfo.id.isEqual(id, true);
+				}
 
 				throw new Error(`Unrecognized ID scope for ID: ${idContentInfo.id}`);
 			},
@@ -142,11 +144,13 @@ export class ContentParser extends DeclarationParser {
 				if (!this.isComplete(maybeParsedCard))
 					return false;
 
-				if (idContentInfo.scope == IDScope.UNIQUE)
+				switch (idContentInfo.scope) {
-					return maybeParsedCard.frontID.isCardEqual(id);
+					case IDScope.Unique:
+						return maybeParsedCard.frontID.isCardEqual(id);
 
-				if (idContentInfo.scope == IDScope.NOTE)
+					case IDScope.Note:
-					return maybeParsedCard.frontID.isEqual(id, true);
+						return maybeParsedCard.frontID.isEqual(id, true);
+				}
 
 				throw new Error(`Unrecognized ID scope for ID: ${idContentInfo.id}`);
 			}
@@ -269,7 +273,7 @@ export class ContentParser extends DeclarationParser {
 
 			cardInfos.push({
 				id: id,
-				scope: IDScope.NOTE,
+				scope: IDScope.Note,
 				contentInfo: {
 					range: {
 						start: currentHeading,
@@ -287,8 +291,8 @@ export class ContentParser extends DeclarationParser {
 
 		// Look for a declaration in the frontmatter
 		if (cache.frontmatter) {
-			for (const key of Declaration.supportedFrontmatterKeys) {
+			for (const key of DeclarationConstants.Frontmatter.KEYS) {
-				const declaration = CardDeclarationAssistant.fromFrontmatter(cache.frontmatter[key]);
+				const declaration = ContentParser.declarationFromFrontmatter(cache.frontmatter[key]);
 				if (declaration) {
 					cardInfos.push({
 						id: fullIDFromDeclaration(declaration, noteID),
@@ -306,7 +310,7 @@ export class ContentParser extends DeclarationParser {
 
 		for (const section of cache.sections ?? []) {
 
-			const declaration = this.getDeclarationFromSection(section, noteID, fileContent);
+			const declaration = ContentParser.getDeclarationFromSection(section, noteID, fileContent);
 			if (!declaration)
 				continue;
 

src/Settings.ts

@@ -4,6 +4,7 @@ import { isString } from "TypeAssistant";
 import { PLUGIN_NAME } from "ui/constants";
 
 export interface PluginSettings {
+	/** Trimmed. */
 	uiPrefix: string;
 	hideCardSectionMarker: boolean;
 	hideDeclarationInReadingView: boolean;
@@ -47,7 +48,7 @@ const DEFAULT_SCHEDULER: FsrsScheduler = {
 
 export type SettingsChanged = (settings: PluginSettings, isExternal: boolean) => void;
 
-export type SettingsChangedInfo = "schedulerConfig"; // | "x"
+export type SettingsChangedInfo = "schedulerConfig";// | typeof UNARY_UNION_DEFAULT;
 
 export class SettingsManager {
 
@@ -55,7 +56,7 @@ export class SettingsManager {
 	public settings: PluginSettings;
 
 	/** Saves the {@link settings} to disk. */
-	public save: (changedInfo?: SettingsChangedInfo) => Promise<void>;
+	public readonly save: (changedInfo?: SettingsChangedInfo) => Promise<void>;
 
 	public static readonly DEFAULT_DATA: PluginSettings = {
 		uiPrefix: PLUGIN_NAME,
@@ -68,11 +69,14 @@ export class SettingsManager {
 		}
 	};
 
-	public constructor(settings: PluginSettings, save: (settings: PluginSettings) => Promise<void>, onSaved: (changedInfo?: SettingsChangedInfo) => void) {
+	public constructor(
+		settings: PluginSettings,
+		save: (settings: PluginSettings) => Promise<void>,
+		onSaved: (changedInfo?: SettingsChangedInfo) => void) {
 		this.settings = settings;
 		this.save = async (changedInfo?: SettingsChangedInfo) => {
 			await save(this.settings);
-			onSaved?.(changedInfo);
+			onSaved(changedInfo);
 			this.notifyOnChangedListeners(false);
 		};
 	}

src/TypeAssistant.ts

@@ -1,7 +1,7 @@
-import { DeckableFullID, FullID, NoteID } from "data/FullID";
+import { DeckableFullID, FullID, NoteID } from "#/data/FullID";
-import { CardDeclarable, CardDeclarationAssistant } from "declarations/CardDeclaration";
+import { CardDeclarable, ExplicitDeclarationAssistant } from "#/declarations/ExplicitDeclaration";
+import { Num, Str } from "#/utils/ts";
 import { TFile } from "obsidian";
-import { Num, Obj, Str } from "utils/ts";
 
 export function asNoteID(value: TFile | string): NoteID {
 	if (value instanceof TFile)
@@ -13,18 +13,8 @@ export function asNoteID(value: TFile | string): NoteID {
 
 export function fullIDFromDeclaration(declaration: CardDeclarable, noteID: NoteID): DeckableFullID | FullID {
 	return declaration.deckID
-		? new DeckableFullID(noteID, declaration.id, CardDeclarationAssistant.isFrontSide(declaration, true), [declaration.deckID])
+		? new DeckableFullID(noteID, declaration.id, ExplicitDeclarationAssistant.isFrontSide(declaration, true), [declaration.deckID])
-		: FullID.create(noteID, declaration.id, CardDeclarationAssistant.isFrontSide(declaration, true));
+		: FullID.create(noteID, declaration.id, ExplicitDeclarationAssistant.isFrontSide(declaration, true));
-}
-
-/**
- * If {@link value} is `null`, `false` is returned even thoigh `null` is an object.
- *
- * @param value
- * @returns `true` if `typeof` for {@link value} returns `"object"` and {@link value} is not `null`.
- */
-export function isObject(value: unknown): value is object {
-	return Obj.is(value);
 }
 
 export function isString(value: unknown): value is string {

src/commands/editor.ts

@@ -0,0 +1,70 @@
+import { UniqueID } from "#/data/UniqueID";
+import t from "#/Localization";
+import { Command, Editor, MarkdownFileInfo, MarkdownView } from "obsidian";
+import { Str } from "utils/ts";
+
+export const EditorCommand = {
+
+	generateId: (): Command => ({
+		id: "generate-id-cursor",
+		name: t.commands.generateId.name,
+		editorCallback: (editor: Editor, _ctx) => {
+			editor.replaceRange(UniqueID.generateID(), editor.getCursor())
+		}
+	}),
+
+	insertReviewUnit: (copyLastPage: boolean): Command => ({
+		id: "insert-review-unit" + (copyLastPage ? "-copy-last-page" : ""),
+		name: "Insert empty declaration under cursor " + (copyLastPage ? "(put answer side in clipboard)" : "(both sides)"),
+		editorCallback: (editor: Editor, ctx: MarkdownView | MarkdownFileInfo) => {
+
+			const file = ctx.file;
+			if (file === null)
+				return;
+
+			const cursor = editor.getCursor();
+			const fileCache = ctx.app.metadataCache.getFileCache(file);
+			const headings = fileCache?.headings || [];
+
+			let headingLevel = 0;
+			for (let i = headings.length - 1; i >= 0; i--) {
+				if (headings[i]!.position.start.line <= cursor.line) {
+					headingLevel = headings[i]!.level;
+					break;
+				}
+			}
+			headingLevel = Math.max(headingLevel + 1, 2);
+			const hashes = '#'.repeat(headingLevel || 2);
+
+			const id = UniqueID.generateID();
+
+			const createCardPage = (isBack: boolean) => {
+				const title = isBack ? "Answer heading" : "Question heading";
+				const side = isBack ? "b" : "f";
+
+				return [
+					`${hashes} ${title}`,
+					Str.LF,
+					"```ct",
+					"id: " + id,
+					"side: " + side,
+					"```",
+					Str.LF,
+					"*Add content here*",
+					Str.LF,
+				].join(Str.LF);
+			};
+
+			const firstPage = createCardPage(false);
+			const lastPage = createCardPage(true);
+			const codeBlock = copyLastPage ? firstPage : firstPage.concat(lastPage);
+
+			editor.replaceRange(codeBlock, cursor);
+			editor.setCursor(editor.offsetToPos(editor.posToOffset(cursor) + firstPage.length - 2));
+
+			if (copyLastPage)
+				navigator.clipboard.writeText(lastPage);
+		}
+	}),
+
+};

src/commands/openView.ts

@@ -3,7 +3,6 @@ import { DeclarationParser } from "declarations/DeclarationParser";
 import t from "Localization";
 import { SelectDeckModal } from "modals/SelectDeckModal";
 import { App, Command, Keymap, MarkdownView, PaneType, TFile } from "obsidian";
-import { UIAssistant } from "ui/UIAssistant";
 import { DecksView } from "views/DecksView";
 import { DefinedContentView } from "views/DefinedContentView";
 import { ReviewView } from "views/review/ReviewView";
@@ -15,6 +14,7 @@ export const OpenView = {
 		const leaf = app.workspace.getLeaf(paneType);
 		await leaf.setViewState({
 			type: DecksView.TYPE,
+			state: DecksView.createViewState(),
 			active: true,
 		});
 	},
@@ -45,21 +45,24 @@ export const OpenView = {
 		};
 
 		const allDecks = dataStore.getAllDecks();
-		if (allDecks.length) {
+		if (allDecks.length > 0) {
 			const modal = new SelectDeckModal(
 				app,
 				dataStore,
-				[...[UIAssistant.allDecksOptionItem()], ...allDecks],
+				allDecks,
-				async (deck, evt) => {
+				(deck, evt) => {
-					await openView(ReviewView.createViewState(deck.id === UIAssistant.DECK_ID_NONE ? null : deck.id), Keymap.isModEvent(evt));
+					openView(
+						ReviewView.createViewState(deck === null ? null : deck.id),
+						Keymap.isModEvent(evt)
+					).catch(console.error);
 				});
 			modal.setPlaceholder(t.modals.selectDeck.placeholder);
 			modal.open();
 		}
 		else {
-			await openView(undefined, paneType);
+			await openView(ReviewView.createViewState(null), paneType);
 		}
-}
+	}
 };
 
 export const OpenViewCommand = {

src/constants.ts

@@ -0,0 +1,14 @@
+import { CssClass as ObsCssClass } from "utils/obs/constants";
+
+const CSS_PREFIX = "come-through-";
+
+export const CssClass = {
+	PREFIX: CSS_PREFIX,
+	View: {
+		WORKSPACE_LEAF_CONTENT_MODIFIER: CSS_PREFIX + ObsCssClass.Workspace.LEAF_CONTENT_MODIFIER,
+	} as const,
+
+	Modal: {
+		CONTENT: CSS_PREFIX + "modal-content",
+	} as const,
+} as const;

src/data/DataStore.ts

@@ -5,7 +5,7 @@ import { deepEqual, strictDeepEqual } from 'fast-equals';
 import { asNoteID, isDate, isString } from "TypeAssistant";
 import { DateTime } from "utils/datetime";
 import { UnexpectedUndefinedError } from "utils/errors";
-import { Obj, Str } from "utils/ts";
+import { Arr, Obj, Str } from "utils/ts";
 
 export interface DataStoreRoot {
 	decks: DecksData;
@@ -15,7 +15,7 @@ export interface DataStoreRoot {
 
 type DecksData = Record<DeckID, DeckData>;
 
-interface DeckData {
+export interface DeckData {
 	/** Name of the deck */
 	n: string;
 	/** Parent decks */
@@ -202,6 +202,10 @@ export class DeckEditor {
 /** Use with {@link DataStore.registerOnChangedCallback} */
 export type DataChanged = (data: DataStoreRoot) => void;
 
+type DataSection = Exclude<keyof DataStoreRoot, "decks"> | "all";
+/** See {@link DataStore.Internal.dispatchSection}. */
+type SectionActions<R> = { [K in DataSection]: () => R; };
+
 export class DataStore {
 
 	public static readonly DEFAULT_DATA: DataStoreRoot = {
@@ -222,6 +226,8 @@ export class DataStore {
 	}
 
 	public cardInfo(id: FullID) {
+		Env.log.data("DataStore:cardInfo: id", id);
+
 		let info = `${id.isFrontSide ? "front" : "back"} of ${id.cardID}`
 
 		const card = this.getCard(id);
@@ -234,7 +240,7 @@ export class DataStore {
 		const decks: DeckData[] = [];
 		for (const deckID of card.d) {
 			const deckData = this.getDeck(deckID);
-			console.assert(deckData);
+			console.assert(deckData !== null);
 			if (deckData !== null)
 				decks.push(deckData);
 		}
@@ -248,7 +254,7 @@ export class DataStore {
 		* @param cb Return value is ignored.
 		*/
 	public createDeck(cb: (editor: DeckEditor) => unknown): DeckIDDataTuple {
-
+		Env.log.data("DataStore:createDeck");
 		const editor = new DeckEditor(UniqueID.generateID(), {
 			n: "",
 			p: [],
@@ -261,18 +267,25 @@ export class DataStore {
 	}
 
 	public editCard(id: FullID, cb: (editor: CardEditor) => boolean) {
+		Env.log.data("DataStore:editCard: id", id);
 		const data = this.getCard(id, true);
 		if (data && cb(new CardEditor(id, data)))
 			this.setDataDirty();
 	}
 
-	public editDeck(id: DeckID, cb: (editor: DeckEditor) => boolean) {
+	/**
-		const data = this.getDeck(id, true);
+		* @returns `null` if {@link id} was not found and {@link cb} was not called. If the {@link id} was found, the {@link DeckData} is returned regardless of whether {@link cb} was called.
-		if (data && cb(new DeckEditor(id, data)))
+		*/
+	public editDeck(id: DeckID, cb: (editor: DeckEditor) => boolean, throwIfNotFound = false): DeckData | null {
+		Env.log.data("DataStore:editDeck: id", id);
+		const data = this.getDeck(id, throwIfNotFound);
+		if (data !== null && cb(new DeckEditor(id, data)))
 			this.setDataDirty();
+		return data;
 	}
 
 	public getDeck(id: DeckID, throwIfNotFound = false): DeckData | null {
+		Env.log.data("DataStore:getDeck: id", id);
 		const data = this.data.decks[id] ?? null;
 		if (data === null && throwIfNotFound)
 			throw new Error(`Deck with ID "${id}" was not found.`);
@@ -280,6 +293,7 @@ export class DataStore {
 	}
 
 	public deleteDeck(idToDelete: DeckID, moveChildrenToID?: DeckID, throwIfNotFound = false) {
+		Env.log.data("DataStore:deleteDeck: idToDelete", idToDelete, "moveChildrenToID", moveChildrenToID);
 		const data = this.getDeck(idToDelete, throwIfNotFound);
 		if (!data)
 			return null;
@@ -312,7 +326,7 @@ export class DataStore {
 		const {
 			predicate,
 		} = options || {};
-
+		Env.log.data("DataStore:getAllDecks: predicate", predicate);
 		const decks: DeckIDDataTuple[] = [];
 
 		for (const [id, data] of Object.entries(this.data.decks)) {
@@ -336,12 +350,13 @@ export class DataStore {
 	* @returns The removed {@link CardData}, or `null` if {@link id} was not found.
 	*/
 	private deleteRemovedCard(id: FullID, throwIfNotFound = false) {
+		Env.log.data("DataStore:deleteRemovedCard: id", id);
 		const removedCard = this.getRemovedCard(id, throwIfNotFound);
 		if (!removedCard)
 			return null;
 
 		const removedNoteData = this.getRemovedNote(id.noteID, throwIfNotFound);
-		Env.assert(removedNoteData);
+		Env.assert(removedNoteData !== null);
 		if (removedNoteData === null)
 			return null;
 
@@ -349,7 +364,7 @@ export class DataStore {
 		this.setDataDirty();
 
 		if (StatisticsHelper.isRemovedNoteEmpty(removedNoteData))
-			this.deleteRemovedNote(id.noteID, throwIfNotFound);
+			this.deleteNote("removed", id.noteID, throwIfNotFound);
 
 		return removedCard;
 	}
@@ -358,11 +373,12 @@ export class DataStore {
 	 * @param removedBeforeDate Delete only items that were removed before this date. Set to `undefined` to delete all items.
 	 */
 	private deleteRemovedCards(removedBeforeDate?: Date) {
-		if (removedBeforeDate) {
+		Env.log.data("DataStore:deleteRemovedCards: removedBeforeDate", removedBeforeDate);
+		if (removedBeforeDate !== undefined) {
 			const time = removedBeforeDate.getTime();
 			this.getAllRemovedCards(undefined, (_cardID: CardID, data: RemovedCardData) => {
 				const date = StatisticsHelper.ensureDate(data.date);
-				Env.dev?.assert(date, "Expected date parsable string.");
+				Env.dev?.assert(date !== null, "Expected date parsable string.");
 				return date && date.getTime() < time ? true : false;
 			}).forEach(tuple => this.deleteRemovedCard(tuple.id));
 		}
@@ -380,18 +396,31 @@ export class DataStore {
 	 * @param throwIfExists If card already exist as active.
 	 */
 	private ensureActiveCard(id: FullID, statisticsFactory: () => StatisticsData, throwIfExists = false) {
+		Env.log.data("DataStore:ensureActiveCard: id", id);
 
-		const removedCard = this.getAllRemovedCards(
+		// First check if already active in any note.
-			undefined, //(noteID, _) => id.hasNoteID(noteID),
+		// - Prevents dublicates, e.g., it the removal event occurs after the add event.
+		const existingActive = Arr.firstOrNull(this.getAllCards((cardID, _) => id.hasCardID(cardID)));
+		if (existingActive !== null) {
+			if (existingActive.id.hasNoteID(id.noteID)) {
+				if (throwIfExists)
+					throw new CardAlreadyExistsError(id, [existingActive.id]);
+				return existingActive.data;
+			}
+			return this.moveActiveCard(existingActive.id, id.noteID);
+		}
+
+		// Check removed
+		const removed = Arr.firstOrNull(this.getAllRemovedCards(undefined,
 			(cardID, _) => id.hasCardID(cardID) // For unique IDs. They can be in different notes. Just match on the hash.
-		).first();
+		));
 
 		this.createActiveNote(id, false);
 		let cardToAdd: CardIDDataTuple;
 
-		if (removedCard) {
+		if (removed !== null) {
-			this.deleteRemovedCard(removedCard.id, true);
+			this.deleteRemovedCard(removed.id, true);
-			cardToAdd = StatisticsHelper.toCardIDDataTuple(id, StatisticsHelper.removedCardToCard(removedCard.data));
+			cardToAdd = StatisticsHelper.toCardIDDataTuple(id, StatisticsHelper.removedCardToCard(removed.data));
 		}
 		else {
 			const deckIDs = id instanceof DeckableFullID ? id.deckIDs : [];
@@ -410,7 +439,7 @@ export class DataStore {
 	 * @returns The created card or `null` if already existed.
 	 */
 	private addAsActiveCard(card: CardIDDataTuple, throwIfExists = false) {
-
+		Env.log.data("DataStore:addAsActiveCard: card", card);
 		if (this.getCard(card.id, false) !== null) {
 			if (throwIfExists)
 				throw new CardAlreadyExistsError(card.id, []);
@@ -432,6 +461,7 @@ export class DataStore {
 	 * @returns Returns the note, whether it was created or not.
 	 */
 	private ensureActiveNote(id: FullID) {
+		Env.log.data("DataStore:ensureActiveNote: id", id);
 		return this.createActiveNote(id, false) ?? this.getNote(id.noteID, true)!;
 	}
 
@@ -439,6 +469,7 @@ export class DataStore {
 	* Returns existing {@link RemovedNoteData} from {@link DataStoreRoot.removed} or creates and returns a new one if not found.
 	*/
 	private ensureRemovedNote(noteID: NoteID) {
+		Env.log.data("DataStore:ensureRemovedNote: noteID", noteID);
 		let note = this.getRemovedNote(noteID);
 		if (!note) {
 			note = StatisticsHelper.createRemovedNoteData();
@@ -454,6 +485,7 @@ export class DataStore {
 	 * @returns The created note or `null` if already existed.
 	 */
 	private createActiveNote(id: FullID, throwIfExists = false): NoteData | null {
+		Env.log.data("DataStore:createActiveNote: id", id);
 		id.throwIfNoNoteID()
 
 		if (this.getNote(id.noteID, false)) {
@@ -471,30 +503,55 @@ export class DataStore {
 	}
 
 	public removeNote(noteID: NoteID) {
+		Env.log.data("DataStore:removeNote: noteID", noteID);
 		return this.moveActiveNoteToRemoved(noteID);
 	}
 
 	public async removeAllCards() {
+		Env.log.data("DataStore:removeAllCards");
 		for (const [noteID, note] of Object.entries(this.data.active)) {
 			for (const cardID of Object.keys(note.cs))
 				this.moveActiveCardToRemoved(StatisticsHelper.createFullID(noteID, cardID));
 		}
 	}
 
-	private moveActiveCardToRemoved(id: FullID, throwIfNotFound = false) {
+	/**
+		* Move an active {@link CardData} to another note.
+		* @param id Item to move.
+		* @param toNoteID Target to move to.
+		* @param throwIfNotFound If set to `true`, throws an error if the card is not found in {@link id} or already exists in {@link toNoteID}.
+		* @returns `null` if item cannot be found or already exists in {@link toNoteID}.
+		*/
+	private moveActiveCard(id: FullID, toNoteID: NoteID, throwIfNotFound = false) {
+		Env.log.data("DataStore:moveActiveCard: id", id, "toNoteID", toNoteID);
+
 		const card = this.deleteActiveCard(id, throwIfNotFound);
-		if (!card)
+		if (card === null)
-			return false;
+			return null;
+
+		const newID = FullID.create(toNoteID, id.cardIDOrThrow(), id.isFrontSide);
+		return this.addAsActiveCard({ id: newID, data: card }, throwIfNotFound);
+	}
+
+	private moveActiveCardToRemoved(id: FullID, throwIfNotFound = false) {
+		Env.log.data("DataStore:moveActiveCardToRemoved: id", id);
+		const card = this.deleteActiveCard(id, throwIfNotFound);
+		if (card === null)
+			return null;
 
 		const removedNote = this.ensureRemovedNote(id.noteID);
-		removedNote.cs[id.cardIDOrThrow()] = StatisticsHelper.cardToRemovedCard(card);
+		const removedItem = StatisticsHelper.cardToRemovedCard(card);
+
+		removedNote.cs[id.cardIDOrThrow()] = removedItem;
 		this.setDataDirty();
-		return true;
+
+		return removedItem;
 	}
 
 	private moveActiveNoteToRemoved(noteID: NoteID, throwIfNotFound = false) {
-		const note = this.deleteActiveNote(noteID, throwIfNotFound);
+		Env.log.data("DataStore:moveActiveNoteToRemoved: noteID", noteID);
-		if (!note)
+		const note = this.deleteNote("active", noteID, throwIfNotFound);
+		if (note === null)
 			return false;
 
 		this.data.removed[noteID] = StatisticsHelper.noteToRemovedNote(note);
@@ -509,6 +566,7 @@ export class DataStore {
 	 * @returns The removed {@link CardData}, or `null` if {@link id} was not found.
 	 */
 	private deleteActiveCard(id: FullID, throwIfNotFound = false) {
+		Env.log.data("DataStore:deleteActiveCard: id", id);
 		id.throwIfNoCardID();
 
 		const note = this.getNote(id.noteID, throwIfNotFound);
@@ -521,41 +579,50 @@ export class DataStore {
 
 		delete note.cs[id.cardID];
 		if (StatisticsHelper.isNoteEmpty(note))
-			this.deleteActiveNote(id.noteID);
+			this.deleteNote("active", id.noteID);
 		this.setDataDirty();
 
 		return card;
 	}
 
 	/**
-	 * Deletes {@link NoteData} with {@link noteID} from {@link DataStoreRoot.active} and returns it.
+		* Deletes {@link NoteData} with {@link noteID} from {@link section} and returns it.
-	 * @param noteID
+		* @param section
-	 * @returns The removed {@link NoteData}, or `null` if {@link noteID} was not found.
+		* @param noteID
-	 */
+		* @returns The removed {@link NoteData}, or `null` if {@link noteID} was not found.
-	private deleteActiveNote(noteID: NoteID, throwIfNotFound = false) {
+		*/
-		const note = this.getNote(noteID, throwIfNotFound);
+	private deleteNote(section: DataSection, noteID: NoteID, throwIfNotFound = false): NoteData | null {
-		if (note !== null) {
+		Env.log.data(`DataStore:deleteNote: section: ${section}, noteID: ${noteID}`);
-			delete this.data.active[noteID];
-			this.setDataDirty();
-		}
-		return note;
-	}
 
-	/**
+		const actions: SectionActions<NoteData | null> = {
-	 * Deletes {@link NoteData} with {@link noteID} from {@link DataStoreRoot.removed} and returns it.
+			active: () => {
-	 * @param noteID
+				const n = this.getNote(noteID, section === "active" && throwIfNotFound); // Because `all` calls `active` first.
-	 * @returns The removed {@link NoteData}, or `null` if {@link noteID} was not found.
+				if (n !== null)
-	 */
+					delete this.data.active[noteID];
-	private deleteRemovedNote(noteID: NoteID, throwIfNotFound = false) {
+				return n;
-		const note = this.getRemovedNote(noteID, throwIfNotFound);
+			},
-		if (note !== null) {
+			removed: () => {
-			delete this.data.removed[noteID];
+				const n = this.getRemovedNote(noteID, throwIfNotFound);
+				if (n !== null)
+					delete this.data.removed[noteID];
+				return n;
+			},
+			all: () => {
+				const note = actions.active();
+				return note !== null ? note : actions.removed();
+			}
+		};
+
+		const note = DataStore.Internal.dispatchSection(section, actions);
+
+		if (note !== null)
 			this.setDataDirty();
-		}
+
 		return note;
 	}
 
 	public getCard(id: FullID, throwIfNotFound = false): CardData | null {
+		Env.log.data("DataStore:getCard: id", id);
 		id.throwIfNoNoteID();
 		id.throwIfNoCardID();
 
@@ -572,6 +639,7 @@ export class DataStore {
 	}
 
 	public getNote(noteID: NoteID, throwIfNotFound = false): NoteData | null {
+		Env.log.data("DataStore:getNote: noteID", noteID);
 		const note = this.data.active[noteID] ?? null;
 		if (note === null && throwIfNotFound)
 			throw new Error(`Note with ID "${noteID}" was not found.`);
@@ -588,6 +656,7 @@ export class DataStore {
 	 * @returns
 	 */
 	private getRemovedNote(noteID: NoteID, throwIfNotFound = false): RemovedNoteData | null {
+		Env.log.data("DataStore:getRemovedNote: noteID", noteID);
 		const note = this.data.removed[noteID] ?? null;
 		if (note === null && throwIfNotFound)
 			throw new Error(`Removed note with ID "${noteID}" was not found.`);
@@ -595,6 +664,7 @@ export class DataStore {
 	}
 
 	private getRemovedCard(id: FullID, throwIfNotFound = false): RemovedCardData | null {
+		Env.log.data("DataStore:getRemovedCard: id", id);
 		const note = this.getRemovedNote(id.noteID, throwIfNotFound);
 		if (!note)
 			return null;
@@ -611,8 +681,8 @@ export class DataStore {
 	 * @returns
 	 */
 	public getAllCardsForDeck(deckID?: DeckID): CardIDDataTuple[] {
-		Env.log.d("DataStore:getAllCardsForDeck:deckID", deckID);
+		Env.log.data("DataStore:getAllCardsForDeck: deckID", deckID);
-		Env.dev?.assert(deckID === undefined || isString(deckID) && deckID !== Env.str.EMPTY, deckID);
+		Env.dev?.assert(deckID === undefined || isString(deckID) && deckID !== Str.EMPTY, deckID);
 		if (deckID === undefined)
 			return this.getAllCards();
 
@@ -629,6 +699,7 @@ export class DataStore {
 	}
 
 	private descendantDecks(parentID?: DeckID): DeckIDDataTuple[] {
+		Env.log.data("DataStore:descendantDecks: parentID", parentID);
 		if (parentID === undefined)
 			return [];
 
@@ -645,13 +716,14 @@ export class DataStore {
 	}
 
 	public getAllCards(cardFilter?: (cardID: CardID, data: CardData) => boolean): CardIDDataTuple[] {
+		Env.log.data("DataStore:getAllCards");
 		return this.getAllCardsWithFilters(undefined, cardFilter);
 	}
 
 	private getAllCardsWithFilters(
 		noteFilter?: (noteID: NoteID, data: NoteData) => boolean,
 		cardFilter?: (cardID: CardID, data: CardData) => boolean): CardIDDataTuple[] {
-
+		Env.log.data("DataStore:getAllCardsWithFilters");
 		const cards: CardIDDataTuple[] = [];
 
 		for (const [noteID, note] of Object.entries(this.data.active)) {
@@ -668,6 +740,7 @@ export class DataStore {
 	}
 
 	public getAllNotes(noteFilter?: (noteID: NoteID, data: NoteData) => boolean): NoteID[] {
+		Env.log.data("DataStore:getAllNotes");
 		if (!noteFilter)
 			return Object.keys(this.data.active).map(k => asNoteID(k));
 		throw new Error("Not Implemented");
@@ -676,7 +749,7 @@ export class DataStore {
 	private getAllRemovedCards(
 		noteFilter?: (noteID: NoteID, data: RemovedNoteData) => boolean,
 		cardFilter?: (cardID: CardID, data: RemovedCardData) => boolean) {
-
+		Env.log.data("DataStore:getAllRemovedCards");
 		const cards: RemovedCardIDDataTuple[] = [];
 
 		for (const [noteID, removedData] of Object.entries(this.data.removed)) {
@@ -720,11 +793,11 @@ export class DataStore {
 	 * @returns `true` if the ID was changed successfully.
 	 */
 	public changeNoteID(oldID: NoteID, newID: NoteID, throwIfNotFound = false) {
-
+		Env.log.data("DataStore:changeNoteID: oldID", oldID, "newID", newID);
 		if (this.getNote(newID))
 			throw new Error(`Cannot overwrite ${newID}.`)
 
-		const deletedNote = this.deleteActiveNote(oldID, throwIfNotFound);
+		const deletedNote = this.deleteNote("active", oldID, throwIfNotFound);
 		if (deletedNote) {
 			this.data.active[newID] = deletedNote;
 			this.setDataDirty();
@@ -817,7 +890,7 @@ export class DataStore {
 	}
 
 	public async save() {
-		Env.log.d(`DataStore:save: dirty: ${this._isDataDirty}`);
+		Env.log.d("DataStore:save: dirty: ", this._isDataDirty);
 		if (this._isDataDirty) {
 			const purgeRemovedBeforeDate = new Date((new Date()).getTime() - (this.purgeThreshold * 1000));
 			this.deleteRemovedCards(purgeRemovedBeforeDate);
@@ -890,6 +963,7 @@ export class DataStore {
 	}
 
 	private triggerDataChanged() {
+		Env.log.data("DataStore:triggerDataChanged", this.registeredChangedCallbacks.length);
 		this.registeredChangedCallbacks.forEach(callback => {
 			try {
 				callback(this.data);
@@ -902,6 +976,23 @@ export class DataStore {
 
 	private registeredChangedCallbacks: DataChanged[] = [];
 
+	private static readonly Internal = {
+		dispatchSection: function <R>(section: DataSection, actions: SectionActions<R>): R {
+			switch (section) {
+				case "active":
+					return actions.active();
+				case "removed":
+					return actions.removed();
+				case "all":
+					return actions.all();
+				default: {
+					const _exhaustiveCheck: never = section;
+					throw new Error(`DataStore: Unhandled section: ${_exhaustiveCheck}`);
+				}
+			}
+		}
+	};
+
 	public readonly filter = {
 		cardsWithoutDeck: (card: CardIDDataTuple) => DataStore.Predicate.cardsInDeck(undefined)(card.id, card.data),
 		cardsInDeck: (deckId: DeckID, card: CardIDDataTuple) => DataStore.Predicate.cardsInDeck(deckId)(card.id, card.data),

src/data/FullID.ts

@@ -1,3 +1,5 @@
+import { Env } from "env";
+
 export type CardID = string;
 export type NoteID = string;
 export type IDFilter = (id: FullID) => boolean;
@@ -136,7 +138,7 @@ export class FullID implements FullID {
    * @throws `Error` if {@link cardSide} is not set.
    */
   public get isFrontSide() {
-    console.assert(this.cardSide);
+    Env.assert(this.cardSide !== undefined);
     if (!this.cardSide)
       throw new Error(`Side not specified on id: ${this.toString()}`);
     return this.cardSide === "f" || this.cardSide === "front";

src/data/SyncManager.ts

@@ -1,10 +1,12 @@
-import { DataStore, StatisticsData } from "data/DataStore";
+import { DataStore, StatisticsData } from "#/data/DataStore";
-import { FullID, NoteID } from "data/FullID";
+import { FullID, NoteID } from "#/data/FullID";
-import { CardDeclarable, CardDeclarationAssistant } from "declarations/CardDeclaration";
+import { DeclarationCodec } from "#/declarations/DeclarationCodec";
-import { DeclarationInfo, DeclarationParser, PostParseInfo } from "declarations/DeclarationParser";
+import { DeclarationInfo, DeclarationParser, PostParseInfo } from "#/declarations/DeclarationParser";
-import { Env } from "env";
+import { CardDeclarable, ExplicitDeclarationAssistant } from "#/declarations/ExplicitDeclaration";
+import { Env } from "#/env";
+import { asNoteID, isString } from "#/TypeAssistant";
+import { UNARY_UNION_SUPPRESS } from "#/utils/ts";
 import { App, CachedMetadata, Editor, FileManager, TAbstractFile, TFile } from "obsidian";
-import { asNoteID, isString } from "TypeAssistant";
 
 /** Keeps the plugin's internal data synchronized with card declarations in the vault by listening for and processing file system events. */
 export class SyncManager {
@@ -44,7 +46,7 @@ export class SyncManager {
 		}
 	}
 
-	public async open(file: TFile | null) {
+	public open = async (file: TFile | null) => {
 		Env.log.d(`SyncManager:open isSuspended: ${this.isSuspended}`);
 		if (this.isSuspended)
 			return;
@@ -53,34 +55,34 @@ export class SyncManager {
 			const ids = await SyncManager.processFile(file, this.app);
 			await this.syncIDs(ids, file);
 		}
-	}
+	};
 
-	public async changed(file: TFile, data: string, cache: CachedMetadata) {
+	public changed = async (file: TFile, data: string, cache: CachedMetadata) => {
 		Env.log.d(`SyncManager:changed isSuspended: ${this.isSuspended}`);
 		if (this.isSuspended)
 			return;
 
 		const ids = await SyncManager.processFileChanged(file, data, cache, this.app);
 		await this.syncIDs(ids, file);
-	}
+	};
 
-	public async delete(file: TAbstractFile) {
+	public delete = async (file: TAbstractFile) => {
 		Env.log.d(`SyncManager:delete isSuspended: ${this.isSuspended}`);
 		if (this.isSuspended)
 			return;
 
 		if (file instanceof TFile && this.dataStore.removeNote(asNoteID(file.path)))
 			await this.dataStore.save();
-	}
+	};
 
-	public async rename(file: TAbstractFile, oldPath: string) {
+	public rename = async (file: TAbstractFile, oldPath: string) => {
 		Env.log.d(`SyncManager:rename isSuspended: ${this.isSuspended}`);
 		if (this.isSuspended)
 			return;
 
 		if (file instanceof TFile && this.dataStore.changeNoteID(asNoteID(oldPath), asNoteID(file), false))
 			await this.dataStore.save();
-	}
+	};
 
 	private static async processFile(file: TFile, app: App) {
 		const { ids, output } = await DeclarationParser.getAllIDsInFile(file, app, (id) => id.isFrontSide)
@@ -104,7 +106,7 @@ export class SyncManager {
 		* The returned values are the {@link FullID}s of those declarations that were completed
 		* and therefore also need to be saved to persistant storage.
 		*
-		* This method is preferred to {@link postProcessWithFile} when the file can be modified via an
+		* This method is preferred over {@link postProcessWithFile} when the file can be modified via an
 		* {@link Editor} instance.
 		*
 		* @param editor
@@ -138,8 +140,8 @@ export class SyncManager {
 				cursorPosition.line <= endPosBeforeModification.line)
 				continue;
 
-			const completeDeclaration = CardDeclarationAssistant.makeValidOrThrow(info.declaration, existingIDs);
+			const completeDeclaration = ExplicitDeclarationAssistant.completeOrThrow(info.declaration, existingIDs);
-			const replacement = CardDeclarationAssistant.toString(completeDeclaration);
+			const replacement = DeclarationCodec.toYaml(completeDeclaration);
 
 			// This will trigger file changed events.
 			editor.replaceRange(
@@ -153,7 +155,7 @@ export class SyncManager {
 			autoGeneratedIDs.push(FullID.create(
 				info.noteID,
 				completeDeclaration.id,
-				CardDeclarationAssistant.isFrontSide(completeDeclaration)
+				ExplicitDeclarationAssistant.isFrontSide(completeDeclaration)
 			));
 
 			diff += replacement.length - (info.location.end - info.location.start);
@@ -196,9 +198,9 @@ export class SyncManager {
 			for (const info of replacementDeclarationInfos) {
 
 				const startOffset = info.section.position.start.offset + info.location.start;
-				const replace = CardDeclarationAssistant.toString(info.declaration);
+				const replace = DeclarationCodec.toYaml(info.declaration);
-				const completeDeclaration = CardDeclarationAssistant.makeValidOrThrow(info.declaration, existingIDs);
+				const completeDeclaration = ExplicitDeclarationAssistant.completeOrThrow(info.declaration, existingIDs);
-				const replacement = CardDeclarationAssistant.toString(completeDeclaration);
+				const replacement = DeclarationCodec.toYaml(completeDeclaration);
 
 				parts.push(data.slice(sliceStartIndex, startOffset));
 				parts.push(replacement);
@@ -216,7 +218,7 @@ export class SyncManager {
 
 	/**
 		* {@link PostParseInfo.incompleteDeclarationInfos} should contain {@link DeclarationInfo}s
-		* that can be represented as statistics items and persisted in disk if some missing values are filled in.
+		* that can be represented as statistics items and persisted to disk if missing values are generated.
 		*
 		* This method filters out declarations that should not be persisted.
 		* @param postInfo As populated by {@link DeclarationParser.getAllIDsInFile} or {@link DeclarationParser.getAllIDsFromMetadata}.
@@ -225,10 +227,10 @@ export class SyncManager {
 	private static getFrontSideInvalidDeclarations(postInfo: PostParseInfo) {
 		const declarations = postInfo.incompleteDeclarationInfos
 			.filter(info => (
-				CardDeclarationAssistant.canMakeValidCardDeclarable(info.declaration) &&
+				ExplicitDeclarationAssistant.canComplete(info.declaration) &&
-				CardDeclarationAssistant.isFrontSide(info.declaration))
+				ExplicitDeclarationAssistant.isFrontSide(info.declaration))
 			);
-		console.assert(postInfo.incompleteDeclarationInfos.length == declarations.length, "Hmm")
+
 		return declarations;
 	}
 
@@ -237,7 +239,7 @@ export class SyncManager {
 		ids.push(FullID.create(
 			noteID,
 			declarable.id,
-			CardDeclarationAssistant.isFrontSide(declarable)
+			ExplicitDeclarationAssistant.isFrontSide(declarable)
 		));
 	}
 
@@ -253,21 +255,29 @@ export class SyncManager {
 	private static async processFrontmatter(file: TFile, fileManager: FileManager, info: DeclarationInfo, preventIDs: Set<string>) {
 		let completeDeclaration: CardDeclarable | null = null;
 
-		if (DeclarationParser.isExternalSectionCache(info.section) && info.section.externalType === "frontmatter") {
+		if (DeclarationParser.isExternalSectionCache(info.section)) {
-			if (CardDeclarationAssistant.isValidCardDeclarable(info.declaration)) {
+			switch (info.section.externalType) {
-				console.assert(false, "Expected an invalid declaration.");
+				case UNARY_UNION_SUPPRESS:
-				completeDeclaration = null; // info.declaration;
+					break;
-			}
+
-			else {
+				case "frontmatter": {
-				// Set default values and modify the file.
+					if (ExplicitDeclarationAssistant.is(info.declaration) && ExplicitDeclarationAssistant.isValid(info.declaration)) {
-				completeDeclaration = CardDeclarationAssistant.makeValidOrThrow(info.declaration, preventIDs);
+						Env.assert(false, "Expected an invalid declaration.");
-				const key = info.section.id;
+						completeDeclaration = null; // info.declaration;
-				if (isString(key)) {
+					}
-					// This seems to work fine while cursor is in the frontmatter (so no need to skip this declaration now because of that).
+					else {
-					await fileManager.processFrontMatter(file, (fm) => fm[key] = completeDeclaration).catch(console.error);
+						// Set default values and modify the file.
-				}
+						completeDeclaration = ExplicitDeclarationAssistant.completeOrThrow(info.declaration, preventIDs);
-				else {
+						const key = info.section.id;
-					console.assert(key, "Expected section id to be set to the frontmatter YAML key assinged to the declaration.");
+						if (isString(key)) {
+							// This seems to work fine while cursor is in the frontmatter (so no need to skip this declaration now because of that).
+							await fileManager.processFrontMatter(file, (fm) => fm[key] = completeDeclaration).catch(console.error);
+						}
+						else {
+							Env.assert(key, "Expected section id to be set to the frontmatter YAML key assinged to the declaration.");
+						}
+					}
+					break;
 				}
 			}
 		}
@@ -279,8 +289,9 @@ export class SyncManager {
 		Env.log.d(`SyncManager:syncIDs isSuspended: ${this.isSuspended}, num IDs: ${ids.length}`);
 		if (this.isSuspended)
 			return;
-		if (ids.length == 0)
+
-			return;
+		// Continue even if ids.length == 0
+		// The syncing mechanism looks at the diffs to be able to determine if IDs were removed.
 
 		try {
 			this.dataStore.syncData(ids, file.path, this.statisticsFactory);

src/declarations/CardDeclaration.ts

@@ -1,228 +1,21 @@
-import { DeckableDeclarable, Declarable, Declaration, DeclarationRange, YamlParseErrorCallback } from "declarations/Declaration";
+import { CardDeclarable, DeclarationSide, IDScope } from "#/declarations/ExplicitDeclaration";
-import { isString } from "TypeAssistant";
+import { DeclarableProperty, NullableStringDeclarableProperty } from "#/declarations/Declarable";
-import { UniqueID } from "data/UniqueID";
-
-export const enum IDScope {
-	UNIQUE,
-	NOTE,
-};
-
-export type DeclarationSide = "front" | "back";
-
-/**
-* A {@link DefaultableCardDeclarable} where all default values are set.
-*/
-export interface CardDeclarable extends DefaultableCardDeclarable {
-	id: string;
-}
-
-/**
- * The minimum required propertes that need to be specified before
- * default values and/or generated values can be applied
- * to turn it into a {@link CardDeclarable}.
- *
- * See also: {@link CardDeclarationAssistant.conformsToDefaultable}.
- */
-export interface DefaultableCardDeclarable extends DeckableDeclarable {
-	side: DeclarationSide;
-}
-
-const DeclarationInterfacePropertyName = {
-	ID: "id",
-	SIDE: "side",
-};
 
 export class CardDeclaration implements CardDeclarable {
+	[key: string]: DeclarableProperty;
+	public deckID: NullableStringDeclarableProperty;
 
 	public readonly id: string;
 	public readonly side: DeclarationSide;
-	public deckID: string | null;
-	[key: string]: unknown;
 
 	public readonly isAutoGenerated: boolean = false;
 	public readonly idScope: IDScope;
 
-	public constructor(id: string, side: DeclarationSide, idScope: IDScope, deckID: string | null = null, isAutoGenerated = false) {
+	public constructor(id: string, side: DeclarationSide, idScope: IDScope, deckID: string | null = null, isAutoGenerated: boolean) {
 		this.id = id;
-		this.side = side.trim().toLowerCase() as DeclarationSide;
+		this.side = side;
 		this.idScope = idScope;
 		this.deckID = deckID;
 		this.isAutoGenerated = isAutoGenerated;
 	}
-
-	public get isFrontSide(): boolean {
-		return CardDeclarationAssistant.isFrontSide(this);
-	}
-}
-
-export class CardDeclarationAssistant extends Declaration {
-
-	public static fromFrontmatter(maybeDeclaration: Record<string, unknown>, incompleteCallback?: (incomplete: DefaultableCardDeclarable, position: DeclarationRange) => void) {
-		if (this.conformsToDeclarable(maybeDeclaration))
-			return new CardDeclaration(maybeDeclaration.id, maybeDeclaration.side, IDScope.UNIQUE, maybeDeclaration.deckID);
-		if (this.conformsToDefaultable(maybeDeclaration) && incompleteCallback)
-			// This position should really be the position in the front matter YAML where the declaration is.
-			// But, since this is the frontmatter, there's no need slice strings as editing is done with `obsidian` `FileManager.processFrontMatter`.
-			incompleteCallback(maybeDeclaration, { start: 0, end: 0 });
-		return null;
-	}
-
-	/**
-	 * @param source The code block including the three ticks at the beginning and end.
-	 * @param onParseError
-	 * @param incompleteCallback Invoked if content of {@link source} is recognized but is missing required properties.
-	 * @returns `null` if this block is unknown or it contains invalid YAML.
-	*/
-	public static parseCodeBlock(
-		source: string,
-		onParseError?: YamlParseErrorCallback,
-		incompleteCallback?: (incomplete: DefaultableCardDeclarable, position: DeclarationRange) => void) {
-
-		const info = super.parseAndCheckCodeBlock(source);
-		if (!info)
-			return null;
-
-		const maybeDeclaration = this.tryParseYaml(info.content, onParseError);
-		if (!maybeDeclaration)
-			return null;
-
-		if (this.conformsToDeclarable(maybeDeclaration)) // Doesn't need to be valid here.
-			return new CardDeclaration(maybeDeclaration.id, maybeDeclaration.side, IDScope.UNIQUE, maybeDeclaration.deckID);
-
-		if (CardDeclarationAssistant.conformsToDefaultable(maybeDeclaration) && incompleteCallback)
-			incompleteCallback(maybeDeclaration, info.location satisfies DeclarationRange);
-
-		return null;
-	}
-
-	//#region
-
-	public static canMakeValidCardDeclarable(decl: unknown): decl is DefaultableCardDeclarable {
-		// Cannot complete if its not the correct object.
-		if (!CardDeclarationAssistant.conformsToDefaultable(decl))
-			return false;
-
-		// Already valid
-		if (CardDeclarationAssistant.isValidCardDeclarable(decl))
-			return false;
-
-		return true;
-	}
-
-	/**
-	* Checks if all values of the given {@link CardDeclarable} are valid.
-	* @param decl
-	* @returns
-	*/
-	public static isValidCardDeclarable(decl: Declarable): decl is CardDeclarable {
-		return (
-			CardDeclarationAssistant.conformsToDeclarable(decl) &&
-
-			// Check all values
-			CardDeclarationAssistant.isIDValid(decl.id) &&
-			CardDeclarationAssistant.isSideValid(decl.side) &&
-			CardDeclarationAssistant.isDeckIDValid(decl.deckID)
-		);
-	}
-
-	/**
-	 * Completes a {@link DefaultableCardDeclarable} by assigning default and generated values
-	 * to non-required properties.
-	 *
-	 * @param decl
-	 * @param preventIDs See {@link UniqueID.generateID}
-	 * @returns `null` if {@link canMakeValidCardDeclarable} returns `false`.
-	 */
-	private static tryToMakeValid(decl: DefaultableCardDeclarable, preventIDs?: Set<string>) {
-		if (this.canMakeValidCardDeclarable(decl)) {
-			const declWithDefaultValues = {
-				...decl,
-				...{
-					// Add all default values
-					id: UniqueID.generateID(preventIDs)
-				}
-			} satisfies CardDeclarable;
-			return declWithDefaultValues as CardDeclarable;
-		}
-		return null;
-	}
-
-	/**
-	 * May use if already checked with {@link canMakeValidCardDeclarable}.
-	 * @param decl
-	 * @param preventIDs See {@link UniqueID.generateID}
-	 * @returns Result of calling {@link tryToMakeValid}.
-	 */
-	public static makeValidOrThrow(decl: DefaultableCardDeclarable, preventIDs?: Set<string>) {
-		const maybeCompleted = this.tryToMakeValid(decl, preventIDs);
-		if (maybeCompleted === null)
-			throw new Error("Could not complete given declaration block.");
-		return maybeCompleted;
-	}
-
-	//#endregion
-
-	//#region
-
-	/**
-		* Check if {@link value} conforms to {@link CardDeclarable};
-		* i.e., if the former can be cast to the latter.
-		*
-		* @param value
-		* @returns `false` if {@link value} is `null`.
-		*/
-	public static conformsToDeclarable(value: unknown): value is CardDeclarable {
-		if (!CardDeclarationAssistant.conformsToDefaultable(value))
-			return false;
-
-		const id = value[DeclarationInterfacePropertyName.ID];
-		if (id === undefined)
-			value[DeclarationInterfacePropertyName.ID] = "";
-		if (isString(id))
-			return true;
-
-		return false; // e.g. id is a number
-	}
-
-	/**
-		* Check if {@link value} conforms to {@link DefaultableCardDeclarable};
-		* i.e., if the former can be cast to the latter.
-		*
-		* @param value
-		* @returns `false` if {@link value} is `null`.
-		*/
-	public static conformsToDefaultable(value: unknown): value is DefaultableCardDeclarable {
-		if (!CardDeclarationAssistant.conformsToDeckable(value))
-			return false;
-
-		if (!Object.hasOwn(value, DeclarationInterfacePropertyName.SIDE))
-			return false;
-
-		return true;
-	}
-
-	private static isIDValid(id: string) {
-		return UniqueID.isValid(id);
-	}
-
-	/**
-	 * @returns `true` if {@link side} is one of the allowed values for {@link DefaultableCardDeclarable.side}
-	 */
-	private static isSideValid(side: string) {
-		return [
-			...this.frontSideValues,
-			...this.backSideValues
-		].includes(side.trim().toLowerCase());
-	}
-
-	public static isFrontSide(decl: DefaultableCardDeclarable, throwIfNotValid = false) {
-		if (throwIfNotValid && !this.isSideValid(decl.side))
-			throw new Error(`Side is not valid: ${decl.side}`);
-		return CardDeclarationAssistant.frontSideValues.includes(decl.side);
-	}
-
-	private static readonly frontSideValues = ["f", "front"];
-	private static readonly backSideValues = ["b", "back"];
-
-	//#endregion
 }

src/declarations/Collectionable.ts

@@ -0,0 +1,82 @@
+import { UniqueID } from "#/data/UniqueID";
+import { Declarable, DeclarableAssistant, NullableStringDeclarableProperty } from "#/declarations/Declarable";
+import { LocalStrictKeys, Obj } from "#/utils/ts";
+
+export interface DeckableDeclarable extends Declarable {
+	/** Optional. */
+	deckID: NullableStringDeclarableProperty;
+}
+
+const DeckableUserKeyName = {
+	DECK: "deck"
+};
+
+const DeckablePropertyName = {
+	DECK_ID: "deckID",
+};
+
+type PropertyNames = LocalStrictKeys<DeckableDeclarable, Declarable>;
+
+/**
+	* Helpers related to {@link DeckableDeclarable}.
+	*/
+export class CollectionableAssistant extends DeclarableAssistant {
+
+	public static override is(value: unknown): value is DeckableDeclarable {
+		if (!DeclarableAssistant.is(value))
+			return false;
+
+		// Optional. Add if not exists
+		if (!Obj.hasKey<DeckableDeclarable, PropertyNames>(value, "deckID"))
+			Obj.setKey<DeckableDeclarable, PropertyNames>(value, "deckID", CollectionableAssistant.PropertyValue.FALLBACK_TO_SYSTEM_DEFAULT);
+
+		if (!DeclarableAssistant.PropertyType.isNullableString(Obj.getKey<DeckableDeclarable, PropertyNames>(value, "deckID")))
+			return false;
+
+		return true;
+	}
+
+	public static override isValid(declarable: DeckableDeclarable) {
+		if (!DeclarableAssistant.isValid(declarable))
+			return false;
+		return declarable.deckID === null || UniqueID.isValid(declarable.deckID);
+	}
+
+	/**
+		* Creates a copy of the declaration with the specified deck ID.
+		*/
+	public static copyWithDeck<T extends DeckableDeclarable>(declaration: T, deckID: string | null): T {
+		return {
+			...declaration,
+			deckID: deckID,
+		};
+	}
+
+	/**
+	 * Transform user friendly YAML keys to interface/class properties.
+	 * Opposite of {@link toUserFriendlyKeys}.
+	 *
+	 * @param obj
+	 */
+	public static override fromUserFriendlyKeys(obj: Record<string, unknown>) {
+		DeclarableAssistant.fromUserFriendlyKeys(obj);
+
+		if (Object.hasOwn(obj, DeckableUserKeyName.DECK)) {
+			const deckID = obj[DeckableUserKeyName.DECK];
+			delete obj[DeckableUserKeyName.DECK];
+			obj[DeckablePropertyName.DECK_ID] = deckID;
+		}
+	}
+
+	public static override toUserFriendlyKeys(obj: Declarable) {
+		DeclarableAssistant.toUserFriendlyKeys(obj);
+
+		if (Object.hasOwn(obj, DeckablePropertyName.DECK_ID)) {
+			const deckID = obj[DeckablePropertyName.DECK_ID];
+			delete obj[DeckablePropertyName.DECK_ID];
+			// Only include if specific deck set.
+			if (deckID)
+				obj[DeckableUserKeyName.DECK] = deckID;
+		}
+	}
+}

src/declarations/CommandDeclaration.ts

@@ -1,106 +0,0 @@
-import { isObject, isString } from "TypeAssistant";
-import { CommandDeclarationParsable } from "declarations/CommandDeclarationParser";
-import { DeckableDeclarable, Declaration, DeclarationRange, YamlParseErrorCallback } from "declarations/Declaration";
-import { AlternateHeadingsAssistant, AlternateHeadingsDeclarable } from "declarations/commands/AlternateHeadings";
-import { HeadingAndDelimiterAssistant, HeadingAndDelimiterDeclarable } from "declarations/commands/HeadingAndDelimiter";
-import { HeadingIsFrontAssistant, HeadingIsFrontDeclarable } from "declarations/commands/HeadingIsFront";
-
-const AlternateHeadingsCommandNames = [
-	"alternate headings", "alt headings", "ah",
-] as const;
-
-const HeadingAndDelimiterCommandNames = [
-	"heading and delimiter", "hd",
-] as const;
-
-const HeadingIsFrontCommandNames = [
-	"heading is front", "hf",
-] as const;
-
-const TableCommandNames = [
-	"table",
-] as const;
-
-const CommandNames = [
-	...AlternateHeadingsCommandNames,
-	...HeadingAndDelimiterCommandNames,
-	...HeadingIsFrontCommandNames,
-	...TableCommandNames,
-] as const;
-
-type CommandName = typeof CommandNames[number];
-
-export interface CommandableDeclarable extends DeckableDeclarable {
-	name: CommandName;
-}
-
-export class CommandDeclarationAssistant extends Declaration {
-
-	/**
-		* @param source
-		* @param onParseError The formatting of {@link source} invalid YAML.
-		* @param onInvalidType
-		* @returns `null` if {@link source} is not recognized.
-		*/
-	public static createParser(
-		source: string,
-		onParseError?: YamlParseErrorCallback,
-		onInvalidType?: (command: CommandableDeclarable, range: DeclarationRange) => void) {
-
-		const info = super.parseAndCheckCodeBlock(source);
-		if (!info)
-			return null;
-
-		const obj = super.tryParseYaml(info.content, onParseError);
-		const commandable = obj && CommandDeclarationAssistant.conforms(obj) ? obj : null;
-		if (!commandable)
-			return null;
-
-		let parser: CommandDeclarationParsable | null = null;
-
-		if (CommandDeclarationAssistant.isAlternateHeadings(commandable))
-			parser = AlternateHeadingsAssistant.tryCreateParser(commandable);
-		else if (CommandDeclarationAssistant.isHeadingAndDelimiter(commandable))
-			parser = HeadingAndDelimiterAssistant.tryCreateParser(commandable);
-		else if (CommandDeclarationAssistant.isHeadingIsFront(commandable))
-			parser = HeadingIsFrontAssistant.tryCreateParser(commandable);
-
-		if (!parser && onInvalidType)
-			onInvalidType(commandable, info.location satisfies DeclarationRange);
-
-		return parser;
-	}
-
-	public static isAlternateHeadings(declaration: CommandableDeclarable): declaration is AlternateHeadingsDeclarable {
-		return AlternateHeadingsCommandNames.includes(declaration.name as any);
-	}
-
-	public static isHeadingAndDelimiter(declaration: CommandableDeclarable): declaration is HeadingAndDelimiterDeclarable {
-		return HeadingAndDelimiterCommandNames.includes(declaration.name as any);
-	}
-
-	public static isHeadingIsFront(declaration: CommandableDeclarable): declaration is HeadingIsFrontDeclarable {
-		return HeadingIsFrontCommandNames.includes(declaration.name as any);
-	}
-
-	/**
-	 * Checks if the provided object minimally conforms to the structure of a {@link CommandableDeclarable}.
-	 * @param obj The object to check.
-	 * @returns `true` if the object has at least the minimum properties expected of a {@link CommandableDeclarable}, `false` otherwise.
-	 */
-	public static conforms(obj: Record<string, any>): obj is CommandableDeclarable {
-		return (
-			isObject(obj) &&
-			Object.hasOwn(obj, "name") && isString(obj.name)
-		);
-	}
-
-	/**
-	 * Whether the type value of the provided {@link CommandableDeclarable} is an valid/existing type.
-	 * @param command
-	 * @returns
-	 */
-	public static isNameValid(command: CommandableDeclarable) {
-		return CommandNames.includes(command.name);
-	}
-}

src/declarations/CommandDeclarationParser.ts

@@ -1,9 +1,17 @@
-import { CardDeclaration, IDScope } from "declarations/CardDeclaration";
+import { CardDeclaration } from "declarations/CardDeclaration";
-import { CommandableDeclarable } from "declarations/CommandDeclaration";
+import { CommandableDeclarable } from "declarations/Commandable";
-import { FileParser, SectionRange } from "utils/obs/FileParser";
+import { IDScope } from "declarations/ExplicitDeclaration";
 import { CacheItem } from "obsidian";
+import { FileParser, SectionRange } from "utils/obs/FileParser";
 
 export interface CommandDeclarationParsable {
+	/**
+		* Creates a {@link CardDeclaration} and adds it to {@link generatedDeclarations}.
+		* @param sectionLevel
+		* @param inBetweenDelimiter
+		* @param index
+		* @param delimiters
+		*/
 	parse(sectionLevel: number, inBetweenDelimiter: CacheItem, index: number, delimiters: CacheItem[]): void;
 	generatedDeclarations: GeneratedContentDeclaration[];
 }
@@ -16,10 +24,26 @@ export type GeneratedContentDeclaration = {
 	range: SectionRange,
 };
 
+/**
+	* Provides common functionality for {@link CommandableDeclarable} parsers.
+	* @abstract
+	*/
 export abstract class CommandDeclarationParser<T extends CommandableDeclarable>
 	extends FileParser
 	implements CommandDeclarationParsable {
 
+	public static readonly Factory = {
+		createEntry: <T extends CommandableDeclarable>(
+			names: readonly string[],
+			ParserClass: {
+				new(commandable: T): CommandDeclarationParsable;
+				tryCreate(value: CommandableDeclarable): CommandDeclarationParsable | null;
+			}) => ({
+				names,
+				create: (d: CommandableDeclarable) => ParserClass.tryCreate(d)
+			})
+	};
+
 	abstract parse(sectionLevel: number, inBetweenDelimiter: CacheItem, index: number, delimiters: CacheItem[]): void;
 	public generatedDeclarations: GeneratedContentDeclaration[] = [];
 
@@ -30,7 +54,12 @@ export abstract class CommandDeclarationParser<T extends CommandableDeclarable>
 		this.commandable = commandable;
 	}
 
-	protected generateDeclaration(id: string, isFront: boolean, startDelimiter: CacheItem | null, endDelimiter: CacheItem | null, scope: IDScope = IDScope.NOTE) {
+	protected generateDeclaration(
+		id: string,
+		isFront: boolean,
+		startDelimiter: CacheItem | null,
+		endDelimiter: CacheItem | null,
+		scope: IDScope = IDScope.Note) {
 		this.generatedDeclarations.push({
 			declaration: new CardDeclaration(
 				id,
@@ -59,4 +88,11 @@ export abstract class CommandDeclarationParser<T extends CommandableDeclarable>
 	protected get lastID() {
 		return this.lastDeclaration().declaration.id;
 	}
+
+	protected tryParseUniqueID(text: string) {
+		const match = this.FULL_ID_REGEX.exec(text);
+		const result = match?.[1];
+		return result !== undefined ? result.toLowerCase() : null;
+	}
+	protected readonly FULL_ID_REGEX = /@([^\s]+)/i;
 }

src/declarations/CommandNames.ts

@@ -0,0 +1,35 @@
+const AlternateHeadingsCommandNames = [
+	"alternate headings", "alt headings", "ah",
+] as const;
+
+const HeadingAndDelimiterCommandNames = [
+	"heading and delimiter", "hd",
+] as const;
+
+const HeadingIsFrontCommandNames = [
+	"heading is front", "hf",
+] as const;
+
+const TableCommandNames = [
+	"table",
+] as const;
+
+const AllCommandNames = [
+	...AlternateHeadingsCommandNames,
+	...HeadingAndDelimiterCommandNames,
+	...HeadingIsFrontCommandNames,
+	...TableCommandNames,
+] as const
+
+export type CommandName = typeof AllCommandNames[number];
+
+export const Commands = {
+	Name: {
+		All: AllCommandNames,
+		AlternateHeadings: AlternateHeadingsCommandNames,
+		HeadingAndDelimiter: HeadingAndDelimiterCommandNames,
+		HeadingIsFront: HeadingIsFrontCommandNames,
+		Table: TableCommandNames,
+		exists: (name: string): name is CommandName => (AllCommandNames as readonly string[]).includes(name),
+	}
+};

src/declarations/Commandable.ts

@@ -0,0 +1,40 @@
+import { CollectionableAssistant, DeckableDeclarable } from "#/declarations/Collectionable";
+import { CommandName, Commands } from "#/declarations/CommandNames";
+import { LocalStrictKeys, Obj, Str } from "#/utils/ts";
+
+/**
+ * @abstract All commands extend this interface.
+ */
+export interface CommandableDeclarable extends DeckableDeclarable {
+	name: CommandName;
+}
+
+type PropertyNames = LocalStrictKeys<CommandableDeclarable, DeckableDeclarable>;
+
+/**
+	* Helpers related to {@link CommandableDeclarable}.
+	*/
+export class CommandableAssistant extends CollectionableAssistant {
+
+	/**
+	 * Checks if the provided object minimally conforms to the structure of a {@link CommandableDeclarable}.
+	 * @param value The object to check.
+	 * @returns `true` if the object has at least the minimum properties expected of a {@link CommandableDeclarable}, `false` otherwise.
+	 */
+	public static override is(value: unknown): value is CommandableDeclarable {
+		if (!CollectionableAssistant.is(value))
+			return false;
+
+		if (!Obj.hasKey<CommandableDeclarable, PropertyNames>(value, "name", (value) => Str.is(value)))
+			return false;
+
+		return true;
+	}
+
+	public static override isValid(declaration: CommandableDeclarable): boolean {
+		if (!CollectionableAssistant.isValid(declaration))
+			return false;
+
+		return Commands.Name.exists(declaration.name);
+	}
+}

src/declarations/Declarable.ts

@@ -0,0 +1,102 @@
+import { Bln, Null, Num, Obj, Str } from "#/utils/ts";
+
+/**
+	* Allowable non-nullable types.
+	*
+	* - {@link DeclarableAssistant.PropertyType.isNullable} needs to be updated if types are added or removed.
+	*/
+type NonNullableDeclarableProperty = string | number | boolean;
+
+/** Allowable types. */
+export type DeclarableProperty = NonNullableDeclarableProperty | null | undefined;
+
+export type StringDeclarableProperty = Extract<DeclarableProperty, string>;
+export type NullableStringDeclarableProperty = Extract<DeclarableProperty, string | null>;
+export type OptionalNullableStringDeclarableProperty = Extract<DeclarableProperty, string | null | undefined>;
+
+export type NumberDeclarableProperty = Extract<DeclarableProperty, number>;
+export type NullableNumberDeclarableProperty = Extract<DeclarableProperty, number | null>;
+export type OptionalNullableNumberDeclarableProperty = Extract<DeclarableProperty, number | null | undefined>;
+
+/**
+	* @abstract
+	*/
+export interface Declarable {
+	[key: string]: DeclarableProperty;
+}
+
+/**
+	* Helpers related to {@link Declarable}.
+	*/
+export class DeclarableAssistant {
+
+	public static is(value: unknown): value is Declarable {
+		return Obj.is(value);
+	}
+
+	public static isValid(_value: unknown): boolean {
+		return true;
+	}
+
+	protected static readonly PropertyValue = {
+		/** Indicates that this optional property was not provided. */
+		OPTIONAL_NOT_ADDED: undefined,
+		/** "I am not providing a value, so use the system default." */
+		FALLBACK_TO_SYSTEM_DEFAULT: null,
+		/** "I am explicitly providing a value, and that value is 'nothing'." */
+		EXPLICIT_EMPTY_STRING: Str.EMPTY,
+		/** This property is of type {@link StringDeclarableProperty} and will be populated with a value programatically. Set it to this temporary value to satisfy the non-nullable type. */
+		AWAITING_VALUE: Str.EMPTY,
+	} as const;
+
+	/**
+	 * Some of these do exactly the same as the {@link PropertyType} equivalents, but use them anyway for "semantic clarity".
+	 */
+	public static readonly PropertyEq = {
+		/** Property was not provided. */
+		optional: (value: unknown): value is typeof DeclarableAssistant.PropertyValue.OPTIONAL_NOT_ADDED =>
+			value === DeclarableAssistant.PropertyValue.OPTIONAL_NOT_ADDED,
+
+		optionalOrNull: (value: unknown): value is typeof DeclarableAssistant.PropertyValue.OPTIONAL_NOT_ADDED | typeof DeclarableAssistant.PropertyValue.FALLBACK_TO_SYSTEM_DEFAULT =>
+			value === DeclarableAssistant.PropertyValue.OPTIONAL_NOT_ADDED || value === null,
+
+		optionalNullOrString: (value: unknown, predicate?: (str: string) => boolean): value is OptionalNullableStringDeclarableProperty =>
+			Str.is(value) && (predicate === undefined || predicate(value)) || DeclarableAssistant.PropertyEq.optionalOrNull(value),
+
+		optionalNullOrNumber: (value: unknown, predicate?: (num: number) => boolean): value is OptionalNullableNumberDeclarableProperty =>
+			Num.is(value) && (predicate === undefined || predicate(value)) || DeclarableAssistant.PropertyEq.optionalOrNull(value),
+
+		any: (value: unknown): value is DeclarableProperty =>
+			Str.is(value) || Num.is(value) || Bln.is(value) || DeclarableAssistant.PropertyEq.optionalOrNull(value),
+	};
+
+	protected static readonly PropertyType = {
+
+		isNullable: (value: unknown) => Null.is(value),
+
+		isNullableString: (value: unknown): value is NullableStringDeclarableProperty => Str.is(value) || Null.is(value),
+
+		isNullableNumber: (value: unknown): value is NullableNumberDeclarableProperty => Num.is(value) || Null.is(value),
+
+		isOptionalNullableString: (value: unknown): value is OptionalNullableStringDeclarableProperty =>
+			value === undefined || DeclarableAssistant.PropertyType.isNullableString(value),
+
+		isOptionalNullableNumber: (value: unknown): value is OptionalNullableNumberDeclarableProperty =>
+			value === undefined || DeclarableAssistant.PropertyType.isNullableNumber(value),
+
+		isStr: (value: unknown): value is StringDeclarableProperty => Str.is(value),
+		isNum: (value: unknown): value is NumberDeclarableProperty => Num.is(value),
+	};
+
+	/**
+	 * Transform user friendly YAML keys to interface/class properties.
+	 * Opposite of {@link toUserFriendlyKeys}.
+	 *
+	 * @param obj
+	 */
+	protected static fromUserFriendlyKeys(_obj: Record<string, unknown>) {
+	}
+
+	protected static toUserFriendlyKeys(_obj: Declarable) {
+	}
+}

src/declarations/Declaration.ts

@@ -1,143 +0,0 @@
-import { FileParser } from "utils/obs/FileParser";
-import { parseYaml, stringifyYaml } from "obsidian";
-import { isObject, isString } from "TypeAssistant";
-import { UniqueID } from "data/UniqueID";
-
-export interface Declarable {
-	[key: string]: unknown;
-}
-
-export interface DeckableDeclarable extends Declarable {
-	deckID: string | null;
-}
-
-const DeckableUserKeyName = {
-	DECK: "deck"
-};
-
-const DeckablePropertyName = {
-	DECK_ID: "deckID",
-};
-
-/**
-	* Locates the portion of a string that contains the raw declaration string.
-	* @todo Remove. See types in {@link FileParser}
-	*/
-export interface DeclarationRange {
-	start: number,
-	end: number,
-}
-
-export type YamlParseErrorCallback = (error: Error) => void;
-
-export abstract class Declaration {
-
-	private static readonly LANGUAGE = "comethrough";
-	private static readonly LANGUAGE_SHORT = "ct";
-
-	public static get supportedCodeBlockLanguages() {
-		return [Declaration.LANGUAGE, Declaration.LANGUAGE_SHORT];
-	}
-
-	public static get supportedFrontmatterKeys() {
-		return [Declaration.LANGUAGE, Declaration.LANGUAGE_SHORT, "come through"];
-	}
-
-	protected static slice(source: string, location: DeclarationRange) {
-		return source.slice(location.start, location.end);
-	}
-
-	/**
-	 	* Checks if this a code block with one of the expected languages; if so, parses it.
-		* @param source The code block including the three ticks at the beginning and end.
-		* @returns `null` is {@link source} is not a code block or if the block's language is unexpected.
-		*/
-	protected static parseAndCheckCodeBlock(source: string) {
-		const info = FileParser.parseCodeBlock(source);
-
-		if (info && !this.supportedCodeBlockLanguages.includes(info.language))
-			return null;
-
-		return info;
-	}
-	private static readonly CODE_BLOCK_MARKER_LENGTH = 3;
-
-	/**
-		* Case insensitive.
-		*
-		* @param yaml Will be converted to lower case before parsing.
-		* @param onParseError
-		* @returns `null` if YAML parsing failed, in which case {@link onParseError} will be invoked.
-		*/
-	public static tryParseYaml(yaml: string, onParseError?: YamlParseErrorCallback) {
-		let parsedObject: Record<string, any> | null = null;
-
-		try {
-			parsedObject = parseYaml(yaml.toLowerCase());
-			if (parsedObject)
-				this.fromUserFriendlyKeys(parsedObject);
-		}
-		catch (error) {
-			if (error instanceof Error && error.name === "YAMLParseError")
-				onParseError?.(error);
-			else
-				throw error;
-		}
-
-		return parsedObject;
-	}
-
-	public static toString(declaration: Declarable) {
-		this.toUserFriendlyKeys(declaration);
-		return stringifyYaml(declaration);
-	}
-
-	/**
-	 * Transform user friendly YAML keys to interface/class properties.
-	 * Opposite of {@link toUserFriendlyKeys}.
-	 *
-	 * @param obj
-	 */
-	private static fromUserFriendlyKeys(obj: Record<string, any>) {
-		if (Object.hasOwn(obj, DeckableUserKeyName.DECK)) {
-			const deckID = obj[DeckableUserKeyName.DECK];
-			delete obj[DeckableUserKeyName.DECK];
-			obj[DeckablePropertyName.DECK_ID] = deckID;
-		}
-	}
-
-	private static toUserFriendlyKeys(obj: Declarable) {
-		if (Object.hasOwn(obj, DeckablePropertyName.DECK_ID)) {
-			const deckID = obj[DeckablePropertyName.DECK_ID];
-			delete obj[DeckablePropertyName.DECK_ID];
-			// Only include if specific deck set.
-			if (deckID)
-				obj[DeckableUserKeyName.DECK] = deckID;
-		}
-	}
-
-	protected static conformsToDeclarableBase(value: unknown): value is Declarable {
-		return isObject(value);
-	}
-
-	protected static conformsToDeckable(value: unknown): value is DeckableDeclarable {
-		if (!Declaration.conformsToDeclarableBase(value))
-			return false;
-		if (!Object.hasOwn(value, DeckablePropertyName.DECK_ID))
-			value[DeckablePropertyName.DECK_ID] = null;
-		return true;
-	}
-
-	public static copyWithDeck<T extends DeckableDeclarable>(declaration: T, deckID: string | null): T {
-		return {
-			...declaration,
-			...{
-				deckID: deckID,
-			} satisfies DeckableDeclarable
-		}
-	}
-
-	protected static isDeckIDValid(id: string | null) {
-		return id === null || (isString(id) && UniqueID.isValid(id));
-	}
-}

src/declarations/DeclarationCodec.ts

@@ -0,0 +1,54 @@
+import { CollectionableAssistant } from "#/declarations/Collectionable";
+import { Declarable } from "#/declarations/Declarable";
+import { Obj } from "#/utils/ts";
+import { parseYaml, stringifyYaml } from "obsidian";
+
+/** Key types are constrained to string keys only. */
+export type YamlObject = Record<string, unknown>;
+export type YamlParseErrorCallback = (error: Error) => void;
+
+export class DeclarationCodec {
+
+	/**
+		* - Case insensitive.
+		* - Values of empty properties (e.g. `prop: `) are set to `null` by the YAML parser as `null` is a valid YAML value. `undefined` does not exist in YAML.
+		*
+		* @param yaml Will be converted to lower case before parsing.
+		* @param onParseError
+		* @returns `null` if YAML parsing failed, in which case {@link onParseError} will be invoked.
+		*/
+	public static tryFromYaml(yaml: string, onParseError?: YamlParseErrorCallback) {
+		let parsedObject: YamlObject | null = null;
+
+		try {
+			const raw = parseYaml(yaml);
+
+			if (Obj.is(raw)) {
+				parsedObject = {};
+
+				for (const [key, value] of Object.entries(raw)) {
+					// - YAML allows keys to be e.g. numbers. Make sure they are strings.
+					// - Also lowercase them to match property names in code (or camel cased)
+					parsedObject[String(key).toLowerCase()] = value;
+				}
+
+				// If the value has white space, e.g. `prop:       `, `null` is still returned as YAML trims whitespace after the colon.
+				// However, content inside quotes are preserverd. `prop: " "` will have the value of a string with a space.
+				Obj.trimValues(parsedObject);
+				CollectionableAssistant.fromUserFriendlyKeys(parsedObject);
+			}
+		} catch (error) {
+			if (error instanceof Error && error.name === "YAMLParseError")
+				onParseError?.(error);
+			else
+				throw error;
+		}
+
+		return parsedObject;
+	}
+
+	public static toYaml(declaration: Declarable): string {
+		CollectionableAssistant.toUserFriendlyKeys(declaration);
+		return stringifyYaml(declaration);
+	}
+}

src/declarations/DeclarationManager.ts

@@ -1,8 +1,12 @@
-import { DataStore } from "data/DataStore";
+import { DataStore } from "#/data/DataStore";
-import { CardDeclarationAssistant } from "declarations/CardDeclaration";
+import { DeckID } from "#/data/FullID";
-import { DeckableDeclarable, Declaration } from "declarations/Declaration";
+import { CollectionableAssistant, DeckableDeclarable } from "#/declarations/Collectionable";
-import { DeclarationRenderChild } from "renderings/declarations/DeclarationRenderChild";
+import { DeclarationConstants } from "#/declarations/constants";
-import { DeckModal } from "modals/DeckModal";
+import { DeclarationCodec } from "#/declarations/DeclarationCodec";
+import { Env } from "#/env";
+import { DeckModal } from "#/modals/DeckModal";
+import { DeclarationRenderChild } from "#/renderings/declarations/DeclarationRenderChild";
+import { HtmlTag } from "#/utils/dom/constants";
 import { App, MarkdownPostProcessorContext, MarkdownSectionInformation, TFile, Vault } from "obsidian";
 
 /**
@@ -13,7 +17,7 @@ import { App, MarkdownPostProcessorContext, MarkdownSectionInformation, TFile, V
 export class DeclarationManager {
 
 	public static get supportedCodeBlockLanguages() {
-		return Declaration.supportedCodeBlockLanguages;
+		return DeclarationConstants.CodeBlock.LANGUAGES;
 	}
 
 	public static async processCodeBlock(
@@ -24,7 +28,8 @@ export class DeclarationManager {
 		data: DataStore) {
 
 		const renderer = new DeclarationRenderChild(el, source, {
-			getAllDecks: () => data.getAllDecks()
+			getAllDecks: () => data.getAllDecks(),
+			getDeck: (id: DeckID) => data.getDeck(id),
 		});
 		ctx.addChild(renderer); // The MarkdownPostProcessorContext manage unload, e.g., when file is closed.
 
@@ -36,44 +41,49 @@ export class DeclarationManager {
 				app.vault,
 				file,
 				() => ctx.getSectionInfo(el),
-				Declaration.toString(changedDeclaration)
+				DeclarationCodec.toYaml(changedDeclaration)
 			);
 		}
 
 		renderer.render((declaration, type, deckSelectEl) => {
 
 			const file = app.vault.getFileByPath(ctx.sourcePath);
-			console.assert(file);
+			Env.assert(file !== null);
 			if (!file)
 				return;
 
-			if (type === "deckAdded") {
+			switch (type) {
-				DeckModal.add(app, data, async (addedDeck) => {
+				case "deckAdded": {
+					DeckModal.add(app, data, async (addedDeck) => {
 
-					// Add a new option for the created deck
+						// Add a new option for the created deck
-					deckSelectEl.createEl("option", {
+						deckSelectEl.createEl(HtmlTag.SELECT.OPTION.NAME, {
-						text: addedDeck.data.n,
+							text: addedDeck.data.n,
-						value: addedDeck.id,
+							value: addedDeck.id,
-					}, (el) => {
+						}, (el) => {
-						el.selected = true;
+							HtmlTag.SELECT.OPTION.select(el);
+						});
+
+						handleChangedDeclaration(
+							CollectionableAssistant.copyWithDeck(declaration, addedDeck.id),
+							file
+						).catch(console.error);
 					});
 
+					break;
+				}
+				case "deckChanged": {
+					const selectedDeckID = HtmlTag.SELECT.OPTION.isNone(deckSelectEl.value) ? null : deckSelectEl.value;
+					if (selectedDeckID === declaration.deckID)
+						return;
+
 					handleChangedDeclaration(
-						CardDeclarationAssistant.copyWithDeck(declaration, addedDeck.id),
+						CollectionableAssistant.copyWithDeck(declaration, selectedDeckID),
 						file
 					).catch(console.error);
-				});
-			}
-			else if (type === "deckChanged") {
 
-				const selectedDeckID = deckSelectEl.value ? deckSelectEl.value : null;
+					break;
-				if (selectedDeckID === declaration.deckID)
+				}
-					return;
-
-				handleChangedDeclaration(
-					CardDeclarationAssistant.copyWithDeck(declaration, selectedDeckID),
-					file
-				).catch(console.error);
 			}
 		});
 	}

src/declarations/DeclarationParser.ts

@@ -1,11 +1,14 @@
-import { FullID, IDFilter, NoteID } from "data/FullID";
+import { FullID, IDFilter, NoteID } from "#/data/FullID";
-import { CardDeclarable, CardDeclarationAssistant, DefaultableCardDeclarable } from "declarations/CardDeclaration";
+import { CommandableAssistant, CommandableDeclarable } from "#/declarations/Commandable";
-import { CommandableDeclarable, CommandDeclarationAssistant } from "declarations/CommandDeclaration";
+import { CommandDeclarationParsable } from "#/declarations/CommandDeclarationParser";
-import { Declaration, DeclarationRange } from "declarations/Declaration";
+import { DeclarationConstants } from "#/declarations/constants";
+import { DeclarationCodec, YamlParseErrorCallback } from "#/declarations/DeclarationCodec";
+import { CardDeclarable, DefaultableCardDeclarable, ExplicitDeclarationAssistant } from "#/declarations/ExplicitDeclaration";
+import { ParserRegistry } from "#/declarations/ParserRegistry";
+import { asNoteID, fullIDFromDeclaration } from "#/TypeAssistant";
+import { UnexpectedUndefinedError } from "#/utils/errors";
+import { FileParser, OffsetRange, SectionRange } from "#/utils/obs/FileParser";
 import { App, CachedMetadata, CacheItem, FrontMatterCache, HeadingCache, SectionCache, TFile } from "obsidian";
-import { asNoteID, fullIDFromDeclaration } from "TypeAssistant";
-import { UnexpectedUndefinedError } from "utils/errors";
-import { FileParser, SectionRange } from "utils/obs/FileParser";
 
 /**
  * Contains auxiliary information collected during the parsing process.
@@ -27,7 +30,7 @@ export interface PostParseInfo {
 }
 
 /**
- * All info needed to extract a {@link CardDeclarationAssistant|declaration block} from a note.
+ * All info needed to extract a {@link CardDeclarable | declaration block} from a note.
  */
 export interface DeclarationInfo extends DeclarationInfoBase {
 	/** The declaration candidate. */
@@ -45,7 +48,7 @@ interface DeclarationInfoBase {
 	/** The {@link SectionCache} in {@link noteID} where declaration was found. */
 	section: SectionCache;
 	/** The location of the declaration within the {@link section}. */
-	location: DeclarationRange;
+	location: OffsetRange;
 }
 
 export class DeclarationParser extends FileParser {
@@ -67,7 +70,7 @@ export class DeclarationParser extends FileParser {
 
 		let cache;
 		try {
-		 cache = this.fileCacheOrThrow(app, file);
+			cache = this.fileCacheOrThrow(app, file);
 		}
 		catch (error) {
 			console.error(error);
@@ -78,7 +81,7 @@ export class DeclarationParser extends FileParser {
 
 		// Check frontmatter for explicit declaration
 		if (cache.frontmatter) {
-			for (const key of Declaration.supportedFrontmatterKeys)
+			for (const key of DeclarationConstants.Frontmatter.KEYS)
 				if (Object.hasOwn(cache.frontmatter, key))
 					return true;
 		}
@@ -94,8 +97,8 @@ export class DeclarationParser extends FileParser {
 			for (const section of cache.sections) {
 				if (this.isCodeSection(section)) {
 					if (fileContent) {
-						const info = this.parseCodeBlock(this.extractContentFromSection(section, fileContent));
+						const info = DeclarationParser.parseCodeBlock(this.extractContentFromSection(section, fileContent));
-						if (info !== null && Declaration.supportedCodeBlockLanguages.includes(info.language))
+						if (info !== null && DeclarationConstants.CodeBlock.isSupportedLanguage(info.language))
 							return true;
 					}
 					else {
@@ -164,7 +167,7 @@ export class DeclarationParser extends FileParser {
 			const declaration = this.getDeclarationFromFrontmatter(cache.frontmatter, noteID, parseInfo);
 			if (declaration) {
 				const id = fullIDFromDeclaration(declaration, noteID);
-				if (!checkExistance(id) && (filter === undefined || (filter && filter(id))))
+				if (!checkExistance(id) && (filter === undefined || filter(id)))
 					ids.push(id);
 			}
 		}
@@ -173,7 +176,7 @@ export class DeclarationParser extends FileParser {
 		for (const currentHeading of cache.headings ?? []) {
 			const id = this.findFullIDInText(currentHeading.heading, noteID);
 			if (id !== null && !checkExistance(id)) {
-				if (filter === undefined || (filter && filter(id)))
+				if (filter === undefined || filter(id))
 					ids.push(id);
 			}
 		}
@@ -183,7 +186,7 @@ export class DeclarationParser extends FileParser {
 
 			const createAndAddIDFromDeclaration = (declaration: CardDeclarable) => {
 				const id = fullIDFromDeclaration(declaration, noteID);
-				if (!checkExistance(id) && (filter === undefined || (filter && filter(id))))
+				if (!checkExistance(id) && (filter === undefined || filter(id)))
 					ids.push(id);
 			}
 
@@ -236,8 +239,8 @@ export class DeclarationParser extends FileParser {
 		* @returns The first declaration found in {@link frontmatter}.
 		*/
 	protected static getDeclarationFromFrontmatter(frontmatter: FrontMatterCache, noteID: NoteID, parseInfo?: PostParseInfo) {
-		for (const key of Declaration.supportedFrontmatterKeys) {
+		for (const key of DeclarationConstants.Frontmatter.KEYS) {
-			const declaration = CardDeclarationAssistant.fromFrontmatter(frontmatter[key], (incomplete, location) => {
+			const declaration = DeclarationParser.declarationFromFrontmatter(frontmatter[key], (incomplete, location) => {
 				parseInfo?.incompleteDeclarationInfos.push({
 					noteID: noteID,
 					declaration: incomplete,
@@ -264,7 +267,7 @@ export class DeclarationParser extends FileParser {
 
 		const source = FileParser.extractContentFromSection(section, fileContent);
 
-		return CardDeclarationAssistant.parseCodeBlock(
+		return DeclarationParser.createExplicitDeclaration(
 			source,
 			(parseError) => {
 				parseInfo?.invalidYaml.push({
@@ -273,12 +276,12 @@ export class DeclarationParser extends FileParser {
 					error: parseError
 				});
 			},
-			(incomplete, location) => {
+			(incomplete, range) => {
 				parseInfo?.incompleteDeclarationInfos.push({
 					noteID: noteID,
 					declaration: incomplete,
 					section: section,
-					location: location,
+					location: range,
 				});
 			}
 		);
@@ -298,7 +301,7 @@ export class DeclarationParser extends FileParser {
 
 		const source = fileContent.slice(section.position.start.offset, section.position.end.offset);
 
-		const parser = CommandDeclarationAssistant.createParser(
+		const parser = DeclarationParser.createCommandDeclarationParser(
 			source,
 			(parseError) => {
 				parseInfo?.invalidYaml.push({
@@ -361,6 +364,98 @@ export class DeclarationParser extends FileParser {
 			});
 	}
 
+	/**
+		* Attempts to create a {@link CardDeclarable} from {@link source}.
+		*
+		* @param source The code block including the three ticks at the beginning and end.
+		* @param onParseError
+		* @param incompleteCallback Invoked if content of {@link source} is recognized but is missing required properties.
+		* @returns `null` if {@link source} is not recognized or it contains invalid YAML.
+	*/
+	private static createExplicitDeclaration(
+		source: string,
+		onParseError?: YamlParseErrorCallback,
+		incompleteCallback?: (incomplete: DefaultableCardDeclarable, range: OffsetRange) => void) {
+
+		const info = DeclarationParser.parseAndCheckCodeBlock(source);
+		if (info === null)
+			return null;
+
+		const obj = DeclarationCodec.tryFromYaml(info.content, onParseError);
+		if (obj === null)
+			return null;
+
+		const declaration = DeclarationParser.tryCreateDeclaration(obj);
+
+		if (declaration === null && ExplicitDeclarationAssistant.Defaultable.is(obj) && incompleteCallback)
+			incompleteCallback(obj, info.location);
+
+		return declaration;
+	}
+
+	protected static declarationFromFrontmatter(obj: Record<string, unknown>, incompleteCallback?: (incomplete: DefaultableCardDeclarable, range: OffsetRange) => void) {
+		const declaration = DeclarationParser.tryCreateDeclaration(obj);
+
+		if (declaration === null && ExplicitDeclarationAssistant.Defaultable.is(obj) && incompleteCallback) {
+			// This position should really be the position in the front matter YAML where the declaration is.
+			// But, since this is the frontmatter, there's no need slice strings as editing is done with `obsidian` `FileManager.processFrontMatter`.
+			incompleteCallback(obj, { start: 0, end: 0 });
+		}
+
+		return declaration;
+	}
+
+	/**
+		* Attempts to create a {@link CommandDeclarationParsable} from {@link source}.
+		*
+		* @param source The raw code block text string of the command declaration.
+		* @param onParseError The formatting of {@link source} invalid YAML.
+		* @param onInvalidType
+		* @returns `null` if {@link source} is not recognized.
+		*/
+	private static createCommandDeclarationParser(
+		source: string,
+		onParseError?: YamlParseErrorCallback,
+		onInvalidType?: (command: CommandableDeclarable, range: OffsetRange) => void): CommandDeclarationParsable | null {
+
+		const info = DeclarationParser.parseAndCheckCodeBlock(source);
+		if (!info)
+			return null;
+
+		const obj = DeclarationCodec.tryFromYaml(info.content, onParseError);
+		const commandable = obj !== null && CommandableAssistant.is(obj) ? obj : null;
+
+		let parser: CommandDeclarationParsable | null = null;
+		if (commandable !== null) {
+
+			parser = ParserRegistry.tryCreate(commandable);
+
+			if (parser === null && onInvalidType)
+				onInvalidType(commandable, info.location);
+		}
+
+		return parser;
+	}
+
+	/**
+		* Checks if this a code block with one of the expected languages; if so, parses it.
+		* @param source The code block including the three ticks at the beginning and end.
+		* @returns `null` is {@link source} is not a code block or if the block's language is unexpected.
+		*/
+	private static parseAndCheckCodeBlock(source: string) {
+		const info = FileParser.parseCodeBlock(source);
+
+		if (info !== null && !DeclarationConstants.CodeBlock.isSupportedLanguage(info.language))
+			return null;
+
+		return info;
+	}
+
+	/** @returns `null` if the {@link obj} is not a valid {@link CardDeclarable} */
+	private static tryCreateDeclaration(obj: Record<string, unknown>) {
+		return ExplicitDeclarationAssistant.is(obj) ? ExplicitDeclarationAssistant.createWithUniqueScope(obj) : null;
+	}
+
 	/**
 		* Finds the {@link SectionRange|range} that is associated and defined by {@link section} as its boundries.
 		*

src/declarations/ExplicitDeclaration.ts

@@ -0,0 +1,190 @@
+import { UniqueID } from "#/data/UniqueID";
+import { CardDeclaration } from "#/declarations/CardDeclaration";
+import { CollectionableAssistant, DeckableDeclarable } from "#/declarations/Collectionable";
+import { Declarable, DeclarableAssistant, DeclarableProperty, OptionalNullableStringDeclarableProperty, StringDeclarableProperty } from "#/declarations/Declarable";
+import { LocalStrictKeys, Obj } from "#/utils/ts";
+
+export const IDScope = {
+	Unique: "unique",
+	Note: "note",
+} as const;
+
+export type IDScope = typeof IDScope[keyof typeof IDScope];
+
+export type DeclarationSide = "front" | "back";
+
+/**
+* A {@link DefaultableCardDeclarable} where all default values are set.
+*/
+export interface CardDeclarable extends DefaultableCardDeclarable {
+	id: StringDeclarableProperty;
+}
+
+/**
+ * The minimum required propertes that need to be specified before
+ * default values and/or generated values can be applied
+ * to turn it into a {@link CardDeclarable}.
+ *
+ * See also: {@link CardDeclarationAssistant.conformsToDefaultable}.
+ */
+export interface DefaultableCardDeclarable extends PageDeclarable, DeckableDeclarable {
+	id: OptionalNullableStringDeclarableProperty;
+}
+
+/** @abstract */
+export interface PageDeclarable extends MaybePageDeclarable {
+	side: DeclarationSide;
+}
+
+/** @sealed */
+export interface MaybePageDeclarable extends Declarable {
+	side: DeclarableProperty;
+}
+
+type DefaultablePropertyNames = LocalStrictKeys<DefaultableCardDeclarable, DeckableDeclarable>;
+type PagePropertyNames = LocalStrictKeys<PageDeclarable, DeckableDeclarable>;
+
+export class ExplicitDeclarationAssistant extends CollectionableAssistant {
+
+	/** @returns `null` if the {@link declaration} is invalid */
+	public static createWithUniqueScope(declaration: CardDeclarable) {
+		if (!ExplicitDeclarationAssistant.isValid(declaration))
+			return null;
+		return new CardDeclaration(declaration.id, declaration.side, IDScope.Unique, declaration.deckID, false);
+	}
+
+	/** @returns `true` if {@link value} is a valid {@link DefaultableCardDeclarable} and conforms to {@link CardDeclarable}. */
+	public static canComplete(value: DefaultableCardDeclarable): value is CardDeclarable {
+		if (!ExplicitDeclarationAssistant.Defaultable.isValid(value))
+			return false;
+
+		// Completing the values of the top-level interface is the same as making it valid.
+		// So if it conforms to the top-level interface it is ready.
+		// Any additional non-completable properties should be added to sub interfaces.
+		if (!ExplicitDeclarationAssistant.is(value))
+			return false;
+
+		// value is top-level interface
+		// - Type of `id` is narrowed.
+		return value.id === ExplicitDeclarationAssistant.PropertyValue.AWAITING_VALUE;
+	}
+
+	/**
+		* Makes a {@link DefaultableCardDeclarable} valid by assigning default and generated values to non-required properties.
+		* May use if already checked with {@link canComplete}.
+		* @param decl
+		* @param preventIDs See {@link UniqueID.generateID}
+		* @returns `null` if {@link canComplete} returns `false`. If {@link declaration} is already a valid {@link CardDeclarable}, returns the same unmodified {@link declaration}. Otherwise, returns a valid {@link CardDeclarable}.
+		* @throws If {@link canComplete} returns `false` or {@link declaration} is already complete/valid.
+		*/
+	public static completeOrThrow(declaration: DefaultableCardDeclarable, preventIDs?: Set<string>) {
+
+		if (!ExplicitDeclarationAssistant.canComplete(declaration))
+			throw new Error("Could not complete declaration.");
+
+		if (ExplicitDeclarationAssistant.isValid(declaration))
+			throw new Error("Declaration already complete.");
+
+		return {
+			...declaration,
+			id: UniqueID.generateID(preventIDs)
+		} satisfies CardDeclarable;
+	}
+
+	public static override isValid(declarable: CardDeclarable) {
+		if (!ExplicitDeclarationAssistant.Defaultable.isValid(declarable))
+			return false;
+
+		if (!UniqueID.isValid(declarable.id))
+			return false;
+
+		return true;
+	}
+
+	public static override is(value: unknown): value is CardDeclarable {
+		if (!ExplicitDeclarationAssistant.Defaultable.is(value))
+			return false;
+
+		if (ExplicitDeclarationAssistant.PropertyEq.optionalOrNull(Obj.getKey<DefaultableCardDeclarable, DefaultablePropertyNames>(value, "id")))
+			Obj.setKey<DefaultableCardDeclarable, DefaultablePropertyNames>(value, "id", ExplicitDeclarationAssistant.PropertyValue.AWAITING_VALUE);
+
+		return true
+	}
+
+	public static readonly Defaultable = {
+
+		is(value: unknown): value is DefaultableCardDeclarable {
+			if (!CollectionableAssistant.is(value))
+				return false;
+
+			if (!Obj.hasKey<DefaultableCardDeclarable, DefaultablePropertyNames>(value, "side"))
+				return false;
+			if (!ExplicitDeclarationAssistant.PropertyType.isStr(Obj.getKey<DefaultableCardDeclarable, DefaultablePropertyNames>(value, "side")))
+				return false;
+
+			// Make sure optional properties are added to the object.
+			if (!Obj.hasKey<DefaultableCardDeclarable, DefaultablePropertyNames>(value, "id"))
+				Obj.setKey<DefaultableCardDeclarable, DefaultablePropertyNames>(value, "id", ExplicitDeclarationAssistant.PropertyValue.OPTIONAL_NOT_ADDED);
+
+			if (!ExplicitDeclarationAssistant.PropertyType.isOptionalNullableString(Obj.getKey<DefaultableCardDeclarable, DefaultablePropertyNames>(value, "id")))
+				return false;
+
+			return true;
+		},
+
+		isValid(declarable: DefaultableCardDeclarable) {
+			if (!CollectionableAssistant.isValid(declarable))
+				return false;
+
+			if (!ExplicitDeclarationAssistant.isSideValid(declarable.side))
+				return false;
+
+			if (!ExplicitDeclarationAssistant.PropertyEq.optionalNullOrString(declarable.id))
+				return false;
+
+			return true;
+		}
+	};
+
+	public static readonly MaybePage = {
+
+		is(value: unknown): value is MaybePageDeclarable {
+			if (!CollectionableAssistant.is(value))
+				return false;
+
+			if (!Obj.hasKey<MaybePageDeclarable, PagePropertyNames>(value, "side"))
+				return false;
+
+			return true;
+		},
+
+		isValid(declarable: MaybePageDeclarable): boolean {
+			if (!DeclarableAssistant.isValid(declarable))
+				return false;
+
+			if (!ExplicitDeclarationAssistant.PropertyEq.any(declarable.side))
+				return false;
+
+			return true;
+		}
+	};
+
+	public static isFrontSide(decl: DefaultableCardDeclarable, throwIfNotValid = false) {
+		if (throwIfNotValid && !this.isSideValid(decl.side))
+			throw new Error(`Side is not valid: ${decl.side}`);
+		return ExplicitDeclarationAssistant.frontSideValues.includes(decl.side);
+	}
+
+	/**
+	 * @returns `true` if {@link side} is one of the allowed values for {@link DefaultableCardDeclarable.side}
+	 */
+	private static isSideValid(side: string) {
+		return [
+			...this.frontSideValues,
+			...this.backSideValues
+		].includes(side.trim().toLowerCase());
+	}
+
+	private static readonly frontSideValues = ["f", "front"];
+	private static readonly backSideValues = ["b", "back"];
+}

src/declarations/ParserRegistry.ts

@@ -0,0 +1,19 @@
+import { CommandableDeclarable } from "#/declarations/Commandable";
+import { CommandDeclarationParsable, CommandDeclarationParser } from "#/declarations/CommandDeclarationParser";
+import { Commands } from "#/declarations/CommandNames";
+import { AlternateHeadingsParser } from "#/declarations/commands/AlternateHeadings";
+import { HeadingAndDelimiterParser } from "#/declarations/commands/HeadingAndDelimiter";
+import { HeadingIsFrontParser } from "#/declarations/commands/HeadingIsFront";
+
+const REGISTRY = [
+	CommandDeclarationParser.Factory.createEntry(Commands.Name.AlternateHeadings, AlternateHeadingsParser),
+	CommandDeclarationParser.Factory.createEntry(Commands.Name.HeadingAndDelimiter, HeadingAndDelimiterParser),
+	CommandDeclarationParser.Factory.createEntry(Commands.Name.HeadingIsFront, HeadingIsFrontParser),
+];
+
+export const ParserRegistry = {
+	tryCreate(commandable: CommandableDeclarable): CommandDeclarationParsable | null {
+		const parsable = REGISTRY.find(e => e.names.includes(commandable.name));
+		return parsable !== undefined ? parsable.create(commandable) : null;
+	}
+};

src/declarations/commands/AlternateHeadings.ts

@@ -1,24 +1,38 @@
-import { CommandableDeclarable } from "declarations/CommandDeclaration";
+import { CommandableDeclarable } from "#/declarations/Commandable";
-import { CommandDeclarationParsable, CommandDeclarationParser } from "declarations/CommandDeclarationParser";
+import { CommandDeclarationParsable } from "#/declarations/CommandDeclarationParser";
-import { HeadingsCommandableAssistant, HeadingsCommandableDeclarable, HeadingsDeclarationParser } from "declarations/commands/HeadingsCommandable";
+import { Commands, CommandName } from "#/declarations/CommandNames";
-import { CacheItem, HeadingCache } from "obsidian";
+import { IDScope } from "#/declarations/ExplicitDeclaration";
+import { HeadingsCommandableAssistant, HeadingsCommandableDeclarable, HeadingsDeclarationParser } from "#/declarations/commands/HeadingsCommandable";
 
-export interface AlternateHeadingsDeclarable extends HeadingsCommandableDeclarable { }
+import { FileParser } from "#/utils/obs/FileParser";
+import { CacheItem } from "obsidian";
 
+export interface AlternateHeadingsDeclarable extends HeadingsCommandableDeclarable { // eslint-disable-line @typescript-eslint/no-empty-object-type
+}
+
+/** Helpers related to {@link AlternateHeadingsDeclarable}. */
 export class AlternateHeadingsAssistant extends HeadingsCommandableAssistant {
-	public static tryCreateParser(commandable: CommandableDeclarable): CommandDeclarationParsable | null {
+
-		return (
+	public static override is(value: unknown): value is AlternateHeadingsDeclarable {
-			AlternateHeadingsAssistant.conforms<AlternateHeadingsDeclarable>(commandable) &&
+		if (!HeadingsCommandableAssistant.is(value))
-			AlternateHeadingsAssistant.isValid(commandable)
+			return false;
-		) ? new AlternateHeadingsParser(commandable) : null;
+
+		return (Commands.Name.AlternateHeadings as readonly CommandName[]).includes(value.name);
 	}
 }
+const ThisAssistant = AlternateHeadingsAssistant;
 
 export class AlternateHeadingsParser extends HeadingsDeclarationParser<AlternateHeadingsDeclarable> {
 
+	public static tryCreate(declarable: CommandableDeclarable): CommandDeclarationParsable | null {
+		if (ThisAssistant.is(declarable) && ThisAssistant.isValid(declarable))
+			return new this(declarable);
+		return null;
+	}
+
 	public parse(parentHeadingLevel: number, inBetweenDelimiter: CacheItem, index: number, delimiters: CacheItem[]) {
 
-		if (!AlternateHeadingsParser.isHeadingCache(inBetweenDelimiter))
+		if (!FileParser.isHeadingCache(inBetweenDelimiter))
 			return;
 
 		// Only interested in headings on the specified level
@@ -26,10 +40,31 @@ export class AlternateHeadingsParser extends HeadingsDeclarationParser<Alternate
 			return;
 
 		const isFront = this.generatedDeclarations.length % 2 == 0;
+		let id: string;
+		let idScope: IDScope;
+
+		if (isFront) {
+			const uniqueID = this.tryParseUniqueID(inBetweenDelimiter.heading);
+			if (uniqueID !== null) {
+				id = uniqueID;
+				idScope = IDScope.Unique;
+			} else {
+				id = inBetweenDelimiter.heading;
+				idScope = IDScope.Note;
+			}
+		}
+		else {
+			const decl = this.lastDeclaration().declaration;
+			id = decl.id;
+			idScope = decl.idScope;
+		}
+
 		this.generateDeclaration(
-			isFront ? inBetweenDelimiter.heading : this.lastID,
+			id,
 			isFront,
 			inBetweenDelimiter,
-			AlternateHeadingsParser.findNextHeading(inBetweenDelimiter.level, index, delimiters));
+			HeadingsDeclarationParser.findNextHeading(inBetweenDelimiter.level, index, delimiters),
+			idScope
+		);
 	}
 }

src/declarations/commands/HeadingAndDelimiter.ts

@@ -1,28 +1,31 @@
-import { IDScope } from "declarations/CardDeclaration";
+import { CommandableDeclarable } from "#/declarations/Commandable";
-import { CommandableDeclarable } from "declarations/CommandDeclaration";
+import { CommandDeclarationParsable, CommandDeclarationParser } from "#/declarations/CommandDeclarationParser";
-import { CommandDeclarationParsable, CommandDeclarationParser } from "declarations/CommandDeclarationParser";
+import { CommandName, Commands } from "#/declarations/CommandNames";
-import { HeadingsCommandableAssistant, HeadingsCommandableDeclarable } from "declarations/commands/HeadingsCommandable";
+import { HeadingsCommandableAssistant, HeadingsCommandableDeclarable } from "#/declarations/commands/HeadingsCommandable";
+import { IDScope } from "#/declarations/ExplicitDeclaration";
+import { UnexpectedUndefinedError } from "#/utils/errors";
+import { UNARY_UNION_SUPPRESS } from "#/utils/ts";
 import { CacheItem, HeadingCache } from "obsidian";
-import { UnexpectedUndefinedError } from "utils/errors";
 
 export interface HeadingAndDelimiterDeclarable extends HeadingsCommandableDeclarable {
-	delimiter: "horizontal rule"
+	delimiter: "horizontal rule" | typeof UNARY_UNION_SUPPRESS;
 }
 
+/** Helpers related to {@link HeadingAndDelimiterDeclarable}. */
 export class HeadingAndDelimiterAssistant extends HeadingsCommandableAssistant {
 
-	public static tryCreateParser(commandable: CommandableDeclarable): CommandDeclarationParsable | null {
+	public static override is(value: unknown): value is HeadingAndDelimiterDeclarable {
-		return (
+		if (!HeadingsCommandableAssistant.is(value))
-			HeadingAndDelimiterAssistant.conforms<HeadingAndDelimiterDeclarable>(commandable) &&
+			return false;
-			HeadingAndDelimiterAssistant.isValid(commandable)
+
-		) ? new HeadingAndDelimiterParser(commandable) : null;
+		return (Commands.Name.HeadingAndDelimiter as readonly CommandName[]).includes(value.name);
 	}
 
-	public static isValid(command: HeadingAndDelimiterDeclarable) {
+	public static override isValid(declarable: HeadingAndDelimiterDeclarable) {
-		return (
+		if (!HeadingsCommandableAssistant.isValid(declarable))
-			super.isValid(command) &&
+			return false;
-			this.isDelimiterValid(command)
+
-		);
+		return ThisAssistant.isDelimiterValid(declarable);
 	}
 
 	private static isDelimiterValid(command: HeadingAndDelimiterDeclarable) {
@@ -32,6 +35,7 @@ export class HeadingAndDelimiterAssistant extends HeadingsCommandableAssistant {
 			switch (command.delimiter as string) {
 				case "hr":
 					setDefault();
+					return true;
 				case "horizontal rule":
 					return true;
 			}
@@ -44,12 +48,17 @@ export class HeadingAndDelimiterAssistant extends HeadingsCommandableAssistant {
 		return false;
 	}
 }
+const ThisAssistant = HeadingAndDelimiterAssistant;
 
 export class HeadingAndDelimiterParser extends CommandDeclarationParser<HeadingAndDelimiterDeclarable> {
 
-	/**
+	public static tryCreate(declarable: CommandableDeclarable): CommandDeclarationParsable | null {
-		* If set, it means that the current iteration is the back side and that this is the expected level of the heading that marks the end of the back side.
+		if (ThisAssistant.is(declarable) && ThisAssistant.isValid(declarable))
- 		*/
+			return new this(declarable)
+		return null;
+	}
+
+	/** If set, it means that the current iteration is the back side and that this is the expected level of the heading that marks the end of the back side. */
 	private lastFrontHeadingLevel: number | undefined;
 
 	public parse(parentHeadingLevel: number, inBetweenDelimiter: CacheItem, index: number, delimiters: CacheItem[]) {
@@ -63,17 +72,17 @@ export class HeadingAndDelimiterParser extends CommandDeclarationParser<HeadingA
 		}
 
 		let id: string;
-		let idScope;
+		let idScope: IDScope;
 
 		if (isDelimiterHeading) {
 			const uniqueID = this.tryParseUniqueID(inBetweenDelimiter.heading);
-			if (uniqueID) {
+			if (uniqueID !== null) {
 				id = uniqueID;
-				idScope = IDScope.UNIQUE;
+				idScope = IDScope.Unique;
 			}
 			else {
 				id = inBetweenDelimiter.heading;
-				idScope = IDScope.NOTE;
+				idScope = IDScope.Note;
 			}
 		}
 		else if (HeadingAndDelimiterParser.isSectionType(inBetweenDelimiter, HeadingAndDelimiterParser.SECTION_TYPE_THEMATICBREAK)) {
@@ -119,12 +128,4 @@ export class HeadingAndDelimiterParser extends CommandDeclarationParser<HeadingA
 	private isOnSpecifiedLevel(parentHeadingLevel: number, section: HeadingCache) {
 		return section.level == parentHeadingLevel + this.commandable.level;
 	}
-
-	private tryParseUniqueID(text: string) {
-		const match = this.FULL_ID_REGEX.exec(text);
-		const result = match?.[1];
-		return result !== undefined ? result.toLowerCase() : null;
-	}
-	protected readonly FULL_ID_REGEX = /@([^\s]+)/i;
-
 }

src/declarations/commands/HeadingIsFront.ts

@@ -1,21 +1,33 @@
-import { CommandableDeclarable } from "declarations/CommandDeclaration";
+import { CommandableDeclarable } from "#/declarations/Commandable";
-import { CommandDeclarationParsable, CommandDeclarationParser } from "declarations/CommandDeclarationParser";
+import { CommandDeclarationParsable } from "#/declarations/CommandDeclarationParser";
-import { HeadingsCommandableAssistant, HeadingsCommandableDeclarable, HeadingsDeclarationParser } from "declarations/commands/HeadingsCommandable";
+import { CommandName, Commands } from "#/declarations/CommandNames";
-import { CacheItem, HeadingCache, Loc } from "obsidian";
+import { HeadingsCommandableAssistant, HeadingsCommandableDeclarable, HeadingsDeclarationParser } from "#/declarations/commands/HeadingsCommandable";
+import { IDScope } from "#/declarations/ExplicitDeclaration";
+import { CacheItem, Loc } from "obsidian";
 
-export interface HeadingIsFrontDeclarable extends HeadingsCommandableDeclarable { }
+export interface HeadingIsFrontDeclarable extends HeadingsCommandableDeclarable { // eslint-disable-line @typescript-eslint/no-empty-object-type
-
-export class HeadingIsFrontAssistant extends HeadingsCommandableAssistant {
-	public static tryCreateParser(commandable: CommandableDeclarable): CommandDeclarationParsable | null {
-		return (
-			HeadingIsFrontAssistant.conforms<HeadingIsFrontDeclarable>(commandable) &&
-			HeadingIsFrontAssistant.isValid(commandable)
-		) ? new HeadingIsFrontParser(commandable) : null;
-	}
 }
 
+/** Helpers related to {@link HeadingIsFrontDeclarable}. */
+export class HeadingIsFrontAssistant extends HeadingsCommandableAssistant {
+
+	public static override is(value: unknown): value is HeadingIsFrontDeclarable {
+		if (!HeadingsCommandableAssistant.is(value))
+			return false;
+
+		return (Commands.Name.HeadingIsFront as readonly CommandName[]).includes(value.name);
+	}
+}
+const ThisAssistant = HeadingIsFrontAssistant;
+
 export class HeadingIsFrontParser extends HeadingsDeclarationParser<HeadingIsFrontDeclarable> {
 
+	public static tryCreate(declarable: CommandableDeclarable): CommandDeclarationParsable | null {
+		if (ThisAssistant.is(declarable) && ThisAssistant.isValid(declarable))
+			return new this(declarable);
+		return null;
+	}
+
 	public parse(parentHeadingLevel: number, inBetweenDelimiter: CacheItem, index: number, delimiters: CacheItem[]) {
 		if (!HeadingIsFrontParser.isHeadingCache(inBetweenDelimiter))
 			return;
@@ -24,7 +36,15 @@ export class HeadingIsFrontParser extends HeadingsDeclarationParser<HeadingIsFro
 		if (!this.isOnSpecifiedLevel(parentHeadingLevel, inBetweenDelimiter))
 			return;
 
-		const id = inBetweenDelimiter.heading;
+		let id = inBetweenDelimiter.heading;
+		let idScope: IDScope = IDScope.Note;
+
+		const uniqueID = this.tryParseUniqueID(inBetweenDelimiter.heading);
+		if (uniqueID !== null) {
+			id = uniqueID;
+			idScope = IDScope.Unique;
+		}
+
 		const startLocation: Loc = {
 			line: inBetweenDelimiter.position.start.line,
 			col: inBetweenDelimiter.position.start.col,
@@ -50,7 +70,9 @@ export class HeadingIsFrontParser extends HeadingsDeclarationParser<HeadingIsFro
 					start: endLocation,
 					end: endLocation,
 				}
-			});
+			},
+			idScope,
+		);
 
 		this.generateDeclaration(
 			id,
@@ -61,7 +83,8 @@ export class HeadingIsFrontParser extends HeadingsDeclarationParser<HeadingIsFro
 					end: endLocation,
 				}
 			},
-			HeadingIsFrontParser.findNextHeading(inBetweenDelimiter.level, index, delimiters)
+			HeadingsDeclarationParser.findNextHeading(inBetweenDelimiter.level, index, delimiters),
+			idScope,
 		);
 	}
 }

src/declarations/commands/HeadingsCommandable.ts

@@ -1,47 +1,79 @@
-import { CommandableDeclarable } from "declarations/CommandDeclaration";
+import { CommandableAssistant, CommandableDeclarable } from "#/declarations/Commandable";
-import { CommandDeclarationParser } from "declarations/CommandDeclarationParser";
+import { CommandDeclarationParser } from "#/declarations/CommandDeclarationParser";
+import { NumberDeclarableProperty, OptionalNullableNumberDeclarableProperty } from "#/declarations/Declarable";
+import { UnexpectedUndefinedError } from "#/utils/errors";
+import { LocalStrictKeys, Obj } from "#/utils/ts";
 import { CacheItem, HeadingCache } from "obsidian";
-import { isNumber } from "TypeAssistant";
-import { UnexpectedUndefinedError } from "utils/errors";
 
 /**
-* @abstract
+	* A command declaration that uses headings as dividers.
-*/
+	* @abstract
-export interface HeadingsCommandableDeclarable extends CommandableDeclarable {
+	*/
-	level: number;
+export interface HeadingsCommandableDeclarable extends DefaultableHeadingsCommandableDeclarable {
+	level: NumberDeclarableProperty;
 }
 
-export abstract class HeadingsCommandableAssistant {
+export interface DefaultableHeadingsCommandableDeclarable extends CommandableDeclarable {
+	level: OptionalNullableNumberDeclarableProperty;
+}
 
-	public static conforms<T extends HeadingsCommandableDeclarable>(command: CommandableDeclarable): command is T {
+type PropertyNames = LocalStrictKeys<DefaultableHeadingsCommandableDeclarable, CommandableDeclarable>;
-		return Object.hasOwn(command, "level");
+
+
+export abstract class HeadingsCommandableAssistant extends CommandableAssistant {
+
+	public static override is(value: unknown): value is HeadingsCommandableDeclarable {
+		if (!This.Defaultable.is(value))
+			return false;
+
+		if (!This.PropertyType.isNum(Obj.getKey<DefaultableHeadingsCommandableDeclarable, PropertyNames>(value, "level")))
+			return false;
+
+		return true;
 	}
 
-	/**
+	public static override isValid(declarable: HeadingsCommandableDeclarable) {
-	 * @param command
+		if (!This.Defaultable.isValid(declarable))
-	 * @returns `true` if the values of properties were valid or undefined, in which case default values were set.
+			return false;
-	 */
+
-	public static isValid(command: HeadingsCommandableDeclarable) {
+		if (declarable.level < 1)
-		return (
+			return false;
-			this.isLevelValid(command)
+
-		);
+		return true;
 	}
 
-	private static isLevelValid(command: HeadingsCommandableDeclarable) {
+	public static readonly Defaultable = {
-		if (isNumber(command.level)) {
+
-			return command.level >= 1;
+		is(value: unknown): value is DefaultableHeadingsCommandableDeclarable {
-		}
+			if (!CommandableAssistant.is(value))
+				return false;
+
+			// Add optional properties with default values.
+			if (!Obj.hasKey<DefaultableHeadingsCommandableDeclarable, PropertyNames>(value, "level"))
+				Obj.setKey<DefaultableHeadingsCommandableDeclarable, PropertyNames>(value, "level", This.PropertyValue.OPTIONAL_NOT_ADDED);
+
+			if (!This.PropertyType.isOptionalNullableNumber(Obj.getKey<DefaultableHeadingsCommandableDeclarable, PropertyNames>(value, "level")))
+				return false;
+
+			return true;
+		},
+
+		isValid(declarable: HeadingsCommandableDeclarable) {
+			if (!CommandableAssistant.isValid(declarable))
+				return false;
+
+			if (!This.PropertyEq.optionalNullOrNumber(declarable.level))
+				return false;
 
-		// If `level` is not set, default to 1; if less than one it's invalid.
-		if (command.level === undefined || command.level === null) {
-			command.level = 1;
 			return true;
 		}
-
-		return false;
 	}
 }
+const This = HeadingsCommandableAssistant;
 
+/**
+	* @abstract
+	*/
 export abstract class HeadingsDeclarationParser<T extends HeadingsCommandableDeclarable>
 	extends CommandDeclarationParser<T> {
 
@@ -66,7 +98,7 @@ export abstract class HeadingsDeclarationParser<T extends HeadingsCommandableDec
 		for (let nextIndex = index + 1; nextIndex < delimiters.length; nextIndex++) {
 			const nextDelimiter = delimiters[nextIndex];
 			if (nextDelimiter === undefined)
-					throw new UnexpectedUndefinedError();
+				throw new UnexpectedUndefinedError();
 			if (HeadingsDeclarationParser.isHeadingCache(nextDelimiter) && headingLevel >= nextDelimiter.level)
 				return nextDelimiter;
 		}

src/declarations/constants.ts

@@ -0,0 +1,17 @@
+const LANGUAGE = "comethrough";
+const LANGUAGE_SHORT = "ct";
+
+export const SUPPORTED_CODEBLOCK_LANGUAGES = [LANGUAGE, LANGUAGE_SHORT];
+
+export const DeclarationConstants = {
+
+	CodeBlock: {
+		LANGUAGES: SUPPORTED_CODEBLOCK_LANGUAGES,
+		isSupportedLanguage: (language: string) => SUPPORTED_CODEBLOCK_LANGUAGES.includes(language.toLowerCase()),
+	} as const,
+
+	Frontmatter: {
+		KEYS: [LANGUAGE, LANGUAGE_SHORT, "come through"]
+	} as const,
+
+} as const;

src/env.ts

@@ -1,14 +1,14 @@
 import { Platform } from "obsidian";
 
-const isProduction = process.env.NODE_ENV === "production";
+const isProduction = process.env["NODE_ENV"] === "production";
 const isDev = !isProduction;
-const noop = () => {};
 
-const noopLogger = {
+const noopLogger: Pick<Console, "debug" | "log" | "info" | "warn" | "error"> = {
-	debug: noop,
+  debug: () => {},
-	log: noop,
+	log: () => { },
-	info: noop,
+  info: () => {},
-	warn: noop,
+  warn: () => {},
+  error: () => {},
 };
 
 const devLogger = isDev ? console : noopLogger;
@@ -22,7 +22,6 @@ export const Env = {
 	/** Debug/Dev context */
 	dev: isDev ? DevContext : undefined,
 	isDev: isDev,
-	noop: noop,
 
 	/** Always logs */
 	error: console.error,
@@ -53,11 +52,12 @@ export const Env = {
 		e: console.error,
 
 		/** Debug log for content processors. See {@link ContentRendererProcessor}. */
-		proc: devLogger.info,  //  devLogger.info : noopLogger.debug,
+		proc: noopLogger.info,
 
 		/** Debug log for views. */
-		view: devLogger.info, //  devLogger.info : noopLogger.debug,
+		view: noopLogger.info,
 
+		data: noopLogger.info,
 	},
 
 	perf: {
@@ -78,12 +78,13 @@ export const Env = {
 	},
 
 	/** If running in mobile app that has very limited screen space. */
-	isPhone: Platform.isPhone,
+	get isPhone(): boolean {
+		return Platform.isPhone;
+	},
+
 	/** If running in mobile app that has sufficiently large screen space. */
-	isTablet: Platform.isTablet,
+	get isTablet(): boolean {
+		return Platform.isTablet;
+	},
 
-
-	str: {
-		EMPTY: "",
-	} as const
 } as const;

src/main.ts

@@ -1,23 +1,24 @@
-import { OpenView, OpenViewCommand } from "commands/openView";
+import { OpenView, OpenViewCommand } from "#/commands/openView";
-import { ReviewViewCommand } from "commands/reviewView";
+import { ReviewViewCommand } from "#/commands/reviewView";
-import { DataStore, DataStoreRoot } from "data/DataStore";
+import { DataStore, DataStoreRoot } from "#/data/DataStore";
-import { SyncManager } from "data/SyncManager";
+import { SyncManager } from "#/data/SyncManager";
-import { UniqueID } from "data/UniqueID";
+import { DeclarationManager } from "#/declarations/DeclarationManager";
-import { DeclarationManager } from "declarations/DeclarationManager";
+import { DeclarationParser } from "#/declarations/DeclarationParser";
-import { DeclarationParser } from "declarations/DeclarationParser";
+import { Env } from "#/env";
-import { Env } from "env";
+import t from "#/Localization";
-import t from "Localization";
+import { ConfirmationModal } from "#/modals/ConfirmationModal";
-import { ConfirmationModal } from "modals/ConfirmationModal";
+import { Scheduler } from "#/scheduling/Scheduler";
-import { Editor, Keymap, MarkdownPostProcessorContext, MarkdownView, Plugin, TFile } from "obsidian";
+import { FsrsSchedulerConfig } from "#/scheduling/types";
-import { Scheduler } from "scheduling/Scheduler";
+import { PluginSettings, SettingsChangedInfo, SettingsManager } from "#/Settings";
-import { FsrsSchedulerConfig } from "scheduling/types";
+import { Icon } from "#/ui/constants";
-import { PluginSettings, SettingsChangedInfo, SettingsManager } from "Settings";
+import { SettingTab } from "#/ui/SettingTab";
-import { Icon } from "ui/constants";
+import { UIAssistant } from "#/ui/UIAssistant";
-import { SettingTab } from "ui/SettingTab";
+import { DomState } from "#/utils/obs/DomState";
-import { UIAssistant } from "ui/UIAssistant";
+import { DecksView } from "#/views/DecksView";
-import { DecksView } from "views/DecksView";
+import { DefinedContentView } from "#/views/DefinedContentView";
-import { DefinedContentView } from "views/DefinedContentView";
+import { ReviewView } from "#/views/review/ReviewView";
-import { ReviewView } from "views/review/ReviewView";
+import { EditorCommand } from "commands/editor";
+import { Keymap, MarkdownPostProcessorContext, Plugin, TFile } from "obsidian";
 
 interface PluginData {
 	settings: PluginSettings;
@@ -25,16 +26,16 @@ interface PluginData {
 }
 
 export default class ComeThroughPlugin extends Plugin {
-	private dataStore: DataStore;
+	private dataStore!: DataStore;
-	private scheduler: Scheduler;
+	private scheduler!: Scheduler;
-	private settingsManager: SettingsManager;
+	private settingsManager!: SettingsManager;
-	private syncManager: SyncManager;
+	private syncManager!: SyncManager;
-	private ui: UIAssistant;
+	private ui!: UIAssistant;
 
-	/** Must referene the latest data before {@link savePluginData} is called. Only needed to hold references in order to pass to {@link Plugin.saveData}, see {@link savePluginData}. */
+	/** Must reference the latest data before {@link savePluginData} is called. Only needed to hold references in order to pass to {@link Plugin.saveData}, see {@link savePluginData}. */
-	private latestPluginDataRef: PluginData;
+	private latestPluginDataRef!: PluginData;
 
-	public async onload() {
+	public override async onload() {
 
 		this.latestPluginDataRef = await ComeThroughPlugin.loadPluginData(this);
 
@@ -44,8 +45,9 @@ export default class ComeThroughPlugin extends Plugin {
 				this.latestPluginDataRef.settings = settings;
 				await this.savePluginData();
 			},
-			this.onSettingsSaved.bind(this)
+			this.onSettingsSaved
 		);
+		DomState.init(this, document);
 
 		this.dataStore = new DataStore(this.latestPluginDataRef.data, this.latestPluginDataRef.settings.removedItemsPurgeThreshold, async (data) => {
 			this.latestPluginDataRef.data = data;
@@ -101,22 +103,19 @@ export default class ComeThroughPlugin extends Plugin {
 		this.addCommand(ReviewViewCommand.toggleInlineInfo(this.app));
 		this.addCommand(ReviewViewCommand.navigateToSourceFile(this.app));
 
-		this.addCommand({
+		this.addCommand(EditorCommand.generateId());
-			id: 'generate-id-cursor',
+		this.addCommand(EditorCommand.insertReviewUnit(false));
-			name: t.commands.generateId.name,
+		this.addCommand(EditorCommand.insertReviewUnit(true));
-			editorCallback: (editor: Editor, _view: MarkdownView) => {
-				editor.replaceRange(UniqueID.generateID(), editor.getCursor())
-			}
-		});
 	}
 
-	public onunload() {
+	public override onunload() {
-		if (this.confirmationModal)
+		DomState.deinit();
+		if (this.confirmationModal !== null)
 			this.confirmationModal.forceClose();
 	}
 
 	/** This is triggered when the data file is modified by an external source, such as a sync service. */
-	public async onExternalSettingsChange() {
+	public override async onExternalSettingsChange() {
 		Env.log.d("Plugin:onExternalSettingsChange");
 
 		const overwrittenDataOnDisk = await ComeThroughPlugin.loadPluginData(this);
@@ -152,9 +151,9 @@ export default class ComeThroughPlugin extends Plugin {
 					if (info.activeChanged || info.collectionsChanged) {
 
 						// Prevent multiple modals opening (as external changes might occur while the modal is showing).
-						if (!this.confirmationModal) {
+						if (this.confirmationModal === null) {
 							this.confirmationModal = new ConfirmationModal(this.app);
-							this.confirmationModal.onClosed = () => this.confirmationModal = undefined;
+							this.confirmationModal.onClosed = () => this.confirmationModal = null;
 							this.confirmationModal.open();
 						}
 
@@ -172,7 +171,7 @@ export default class ComeThroughPlugin extends Plugin {
 			);
 		});
 	}
-	private confirmationModal?: ConfirmationModal;
+	private confirmationModal: ConfirmationModal | null = null;
 
 	// public onUserEnable(): void {}
 
@@ -182,10 +181,10 @@ export default class ComeThroughPlugin extends Plugin {
 	 */
 	private registerEvents() {
 
-		this.registerEvent(this.app.workspace.on("file-open", this.syncManager.open.bind(this.syncManager)));
+		this.registerEvent(this.app.workspace.on("file-open", this.syncManager.open));
-		this.registerEvent(this.app.metadataCache.on("changed", this.syncManager.changed.bind(this.syncManager)));
+		this.registerEvent(this.app.metadataCache.on("changed", this.syncManager.changed));
-		this.registerEvent(this.app.vault.on("delete", this.syncManager.delete.bind(this.syncManager)));
+		this.registerEvent(this.app.vault.on("delete", this.syncManager.delete));
-		this.registerEvent(this.app.vault.on("rename", this.syncManager.rename.bind(this.syncManager)));
+		this.registerEvent(this.app.vault.on("rename", this.syncManager.rename));
 
 		this.registerEvent(this.app.workspace.on("file-menu", (menu, file, source, _leaf) => {
 			if (!(file instanceof TFile))
@@ -236,17 +235,18 @@ export default class ComeThroughPlugin extends Plugin {
 		await this.saveData(this.latestPluginDataRef);
 	}
 
-	private onSettingsSaved(changedInfo?: SettingsChangedInfo) {
+	private onSettingsSaved = (changedInfo?: SettingsChangedInfo) => {
 		switch (changedInfo) {
 			case "schedulerConfig":
 				this.scheduler.reconfigure(this.createSchedulerConfig());
 				break;
+			case undefined:
+				break;
 		}
-	}
+	};
 
 	private createSchedulerConfig() {
 		const config = this.settingsManager.defaultScheduler.config;
-		Env.assert(config);
 		return {
 			enableFuzz: config.enableFuzz,
 		} satisfies FsrsSchedulerConfig;

src/modals/BaseModal.ts

@@ -1,6 +1,7 @@
-import { Env } from "env";
+import { CssClass } from "#/constants";
+import { Env } from "#/env";
+import { CssClass as ObsCssClass } from "#/utils/obs/constants";
 import { App, Modal, Setting } from "obsidian";
-import { CssClass } from "utils/obs/constants";
 
 /**
  * - Adds a plugin specific class to all modals for styling purposes.
@@ -29,15 +30,15 @@ export class BaseModal extends Modal {
 		// "Show debug info" modal has this class which makes the height 100% on mobile, i.e. fullscreen.
 		// If modal contains a lot of content and therefore expands in height, it will never fill the entire screen. So in those cases, it's better to force fullscreen.
 		if (options?.fullscreenOnLimitedScreenSpace && Env.isPhone)
-			this.modalEl.addClass(CssClass.Modal.LG);
+			this.modalEl.addClass(ObsCssClass.Modal.LG);
 
-		this.contentEl.addClass("come-through-modal-content");
+		this.contentEl.addClass(CssClass.Modal.CONTENT);
 	}
 
 	protected createSetting(name: string, o?: { styleControlElAsDesc?: boolean, isHeading?: boolean }) {
 		const s = new Setting(this.contentEl).setName(name)
 		if (o?.styleControlElAsDesc)
-			s.controlEl.addClass(CssClass.Setting.Item.DESC);
+			s.controlEl.addClass(ObsCssClass.Setting.Item.DESC);
 		if (o?.isHeading)
 			s.setHeading();
 		return s;
@@ -46,9 +47,9 @@ export class BaseModal extends Modal {
 	/** Using this you get better bottom margins on mobile than adding buttons on a `Setting`. */
 	protected getButtonContainer() {
 		// Try to find existing button container, or create one if it doesn't exist
-		let buttonContainer = this.modalEl.querySelector<HTMLElement>("." + CssClass.Modal.BUTTON_CONTAINER);
+		let buttonContainer = this.modalEl.querySelector<HTMLElement>("." + ObsCssClass.Modal.BUTTON_CONTAINER);
 		if (buttonContainer === null)
-			buttonContainer = this.contentEl.createDiv(CssClass.Modal.BUTTON_CONTAINER);
+			buttonContainer = this.contentEl.createDiv(ObsCssClass.Modal.BUTTON_CONTAINER);
 		return buttonContainer;
 	}
 
@@ -58,7 +59,7 @@ export class BaseModal extends Modal {
 
 		this.getButtonContainer().createEl("button", {
 			text: "Done",
-			cls: CssClass.Modal.CANCEL,
+			cls: ObsCssClass.Modal.CANCEL,
 		}, (button => {
 			button.addEventListener("click", () => this.close());
 		}))

src/modals/DeckModal.ts

@@ -1,116 +1,132 @@
-import { DataStore, DeckEditor, DeckIDDataTuple } from "data/DataStore";
+import { DataStore, DeckEditor, DeckIDDataTuple } from "#/data/DataStore";
-import { DeckID } from "data/FullID";
+import { DeckID } from "#/data/FullID";
-import { BaseModal } from "modals/BaseModal";
+import { BaseModal } from "#/modals/BaseModal";
+import { HtmlTag } from "#/utils/dom/constants";
+import { Str } from "#/utils/ts";
 import { App, ButtonComponent, Setting } from "obsidian";
-import { UIAssistant } from "ui/UIAssistant";
 
+export type OnSubmitCallback = (deck: DeckIDDataTuple) => void;
 
 export class DeckModal extends BaseModal {
 
-  private nameOfDeck: string = "";
+	private nameOfDeck: string = Str.EMPTY;
-  private parentDeckID: DeckID | null;
+	private parentDeckID: DeckID | null = null;
-  private createButton: ButtonComponent;
+	private createButton!: ButtonComponent;
-  private result?: DeckIDDataTuple;
+	private result: DeckIDDataTuple | undefined;
 
-  public static add(app: App,
+	private readonly data: DataStore;
-    data: DataStore,
+	private readonly onSubmit: OnSubmitCallback | undefined;
-    onAdded: (deck: DeckIDDataTuple) => void) {
+	private readonly idToEdit: DeckID | undefined;
-      new DeckModal(app, data, onAdded).open();
-  }
 
-  constructor(
+	public static add(
-    readonly app: App,
+		app: App,
-    private readonly data: DataStore,
+		data: DataStore,
-    private readonly onSubmit: (deck: DeckIDDataTuple) => void,
+		onAdded?: OnSubmitCallback) {
-    private readonly idToEdit?: DeckID) {
+		new DeckModal(app, data, onAdded).open();
-    super(app, { fullscreenOnLimitedScreenSpace: true });
+	}
 
-    if (idToEdit) {
+	public static edit(
-      const deckToEdit = data.getDeck(idToEdit, true)!;
+		app: App,
-      this.nameOfDeck = deckToEdit.n;
+		data: DataStore,
-      this.parentDeckID = DeckEditor.parent(deckToEdit);
+		id: DeckID,
-      this.setTitle("Edit deck");
+		onSubmit?: OnSubmitCallback) {
-    }
+		new DeckModal(app, data, onSubmit, id).open();
-    else {
+	}
-      this.setTitle("Create a new deck");
-    }
 
-    new Setting(this.contentEl)
+	private constructor(
-      .setName("Name")
+		app: App,
-      .addText((component) => {
+		data: DataStore,
-        component.setValue(this.nameOfDeck);
+		onSubmit?: OnSubmitCallback,
-        component.onChange((text) => {
+		idToEdit?: DeckID
-          this.nameOfDeck = text;
+	) {
-          this.createButton.setDisabled(this.nameOfDeck.trim().length == 0);
+		super(app, { fullscreenOnLimitedScreenSpace: true });
-        });
+		this.data = data;
-      });
+		this.onSubmit = onSubmit;
+		this.idToEdit = idToEdit;
 
-    new Setting(this.contentEl)
+		if (idToEdit) {
-      .setName("Parent deck")
+			const deckToEdit = data.getDeck(idToEdit, true)!;
-      .setDesc(idToEdit ? "" : "To make this deck a subdeck, choose a parent deck.")
+			this.nameOfDeck = deckToEdit.n;
-      .addDropdown((component) => {
+			this.parentDeckID = DeckEditor.parent(deckToEdit);
+			this.setTitle("Edit deck");
+		}
+		else {
+			this.setTitle("Create a new deck");
+		}
 
-        component.addOption(UIAssistant.DECK_ID_NONE, "None");
+		new Setting(this.contentEl)
-        for (const deck of this.data.getAllDecks().filter(d => d.id !== this.idToEdit))
+			.setName("Name")
-            component.addOption(deck.id, deck.data.n);
+			.addText((component) => {
-        component.setValue(this.parentDeckID ?? UIAssistant.DECK_ID_NONE);
+				component.setValue(this.nameOfDeck);
+				component.onChange((text) => {
+					this.nameOfDeck = text;
+					this.createButton.setDisabled(this.nameOfDeck.trim().length == 0);
+				});
+			});
 
-        component.onChange((value) => {
+		new Setting(this.contentEl)
-          this.parentDeckID = value === UIAssistant.DECK_ID_NONE ? null : value;
+			.setName("Parent deck")
-        });
+			.setDesc(idToEdit ? "" : "To make this deck a subdeck, choose a parent deck.")
-      });
+			.addDropdown((component) => {
 
-    new Setting(this.contentEl)
+				component.addOption(HtmlTag.SELECT.OPTION.Values.NONE, "None");
-      .addButton((button) => {
+				for (const deck of this.data.getAllDecks().filter(d => d.id !== this.idToEdit))
-        this.createButton = button;
+					component.addOption(deck.id, deck.data.n);
-        button.setDisabled(this.nameOfDeck.trim().length == 0);
+				component.setValue(this.parentDeckID ?? HtmlTag.SELECT.OPTION.Values.NONE);
-        button.setCta()
-        button.setButtonText(this.idToEdit ? "Save" : "Create new deck");
-        button.onClick(async () => {
-          button.setDisabled(true);
-          await this.submit();
-          this.close();
-        });
-      })
-      .addButton((button) => {
-        button.setButtonText("Cancel");
-        button.onClick(() => {
-          this.close();
-        });
-      });
-  }
 
-  // onOpen(): void {
+				component.onChange((value) => {
-  //   super.onOpen();
+					this.parentDeckID = HtmlTag.SELECT.OPTION.isNone(value) ? null : value;
-  // }
+				});
+			});
 
-  onClose(): void {
+		new Setting(this.contentEl)
-    super.onClose();
+			.addButton((button) => {
+				this.createButton = button;
+				button.setDisabled(this.nameOfDeck.trim().length == 0);
+				button.setCta()
+				button.setButtonText(Str.isNonEmpty(this.idToEdit) ? "Save" : "Create new deck");
+				button.onClick(async () => {
+					button.setDisabled(true);
+					await this.submit();
+					this.close();
+				});
+			})
+			.addButton((button) => {
+				button.setButtonText("Cancel");
+				button.onClick(() => {
+					this.close();
+				});
+			});
+	}
 
-    if (this.result) {
+	public override onClose(): void {
-      const result = this.result;
+		super.onClose();
-      setTimeout(() => this.onSubmit(result), 1);
-    }
-  }
 
-  private async submit() {
+		if (this.onSubmit !== undefined && this.result !== undefined) {
-    const cb = (editor: DeckEditor) => {
+			const result = this.result;
-      editor.setName(this.nameOfDeck);
+			const onSubmit = this.onSubmit;
-      editor.setParent(this.parentDeckID);
+			setTimeout(() => onSubmit(result), 1);
-      return true;
+		}
-    };
+	}
 
-    let deckID: DeckID;
+	private async submit() {
-    if (this.idToEdit) {
+		const cb = (editor: DeckEditor) => {
-      deckID = this.idToEdit;
+			editor.setName(this.nameOfDeck);
-      this.data.editDeck(this.idToEdit, cb);
+			editor.setParent(this.parentDeckID);
-    }
+			return true;
-    else {
+		};
-      deckID = this.data.createDeck(cb).id;
-    }
-    await this.data.save();
 
-    const deck = this.data.getDeck(deckID, true);
+		let deckID: DeckID;
-    this.result = { id: deckID, data: deck! };
+		if (this.idToEdit !== undefined) {
-  }
+			deckID = this.idToEdit;
+			const edited = this.data.editDeck(this.idToEdit, cb);
+			if (edited !== null)
+				this.result = { id: deckID, data: edited };
+		}
+		else {
+			const created = this.data.createDeck(cb);
+			this.result = { id: created.id, data: created.data };
+		}
+		await this.data.save();
+	}
 }

src/modals/ReviewItemInfoModal.ts

@@ -107,7 +107,7 @@ export class ReviewItemInfoModal extends BaseModal {
 			.setDesc("The number of review units left in the current review queue.");
 
 		new TableSectionCreator(el.controlEl.createEl("table")).addBody(rowCreator => {
-			entries.forEach(([date, value], index) => {
+			entries.forEach(([date, value], _index) => {
 				let timeString: string;
 				const hours = date.getHours();
 				const minutes = date.getMinutes();
@@ -169,7 +169,7 @@ export class ReviewItemInfoModal extends BaseModal {
 			.setDesc("The number of review units left in the current review queue below the given retrievability.");
 
 		new TableSectionCreator(el.controlEl.createEl("table")).addBody(rowCreator => {
-			entries.forEach(([threshold, value], index) => {
+			entries.forEach(([threshold, value], _index) => {
 				rowCreator.add((col) => {
 					col.add({ text: `Below ${threshold * 100}%:` });
 					col.add({ text: `${Str.NON_BREAKING_SPACE}${value}` });

src/modals/SelectDeckModal.ts

@@ -1,21 +1,43 @@
-import { DataStore, DeckIDDataTuple } from "data/DataStore";
+import { DataStore, DeckIDDataTuple } from "#/data/DataStore";
+import { HtmlTag } from "#/utils/dom/constants";
 import { App, SuggestModal } from "obsidian";
-import { UIAssistant } from "ui/UIAssistant";
 
+const ALL_DECKS = {
+  id: HtmlTag.SELECT.OPTION.Values.NONE,
+  data: {
+    n: "All Decks",
+    p: []
+  }
+};
+
+function isAllDecks(deck: DeckIDDataTuple): boolean {
+  return HtmlTag.SELECT.OPTION.isNone(deck.id);
+}
+
+/**
+	* A `null` value indicates that the user selected "All Decks".
+	*/
+export type OnChooseCallback = (deck: DeckIDDataTuple | null, evt: MouseEvent | KeyboardEvent) => void;
 
 export class SelectDeckModal extends SuggestModal<DeckIDDataTuple> {
 
-  private decks: DeckIDDataTuple[];
+	private decks: DeckIDDataTuple[];
 
+	private readonly onChoose: OnChooseCallback | undefined;
+
+	/**
+		* @param decks If you already have all decks, or if you want to display a subset.
+		*/
   constructor(
     app: App,
     private readonly data: DataStore,
     decks?: DeckIDDataTuple[],
-    private readonly onChoose?: (deck: DeckIDDataTuple, evt: MouseEvent | KeyboardEvent) => void) {
+    onChoose?: OnChooseCallback) {
     super(app);
 
     this.setPlaceholder("Select deck");
-    this.decks = decks ?? this.data.getAllDecks();
+		this.decks = [...[ALL_DECKS], ...decks ?? this.data.getAllDecks()];
+		this.onChoose = onChoose;
   }
 
   getSuggestions(query: string): DeckIDDataTuple[] | Promise<DeckIDDataTuple[]> {
@@ -23,13 +45,13 @@ export class SelectDeckModal extends SuggestModal<DeckIDDataTuple> {
   }
 
   renderSuggestion(value: DeckIDDataTuple, el: HTMLElement): void {
-    const numberOfCards = this.data.getAllCardsForDeck(value.id === UIAssistant.DECK_ID_NONE ? undefined : value.id).length;
+    const numberOfCards = this.data.getAllCardsForDeck(isAllDecks(value) ? undefined : value.id).length;
     el.createEl('div', { text: `${value.data.n}` }).createEl('small', { text: ` (${numberOfCards})` });
     el.createEl('small', { text: value.data.p.length > 0 ? this.descendants(value) : "" });
   }
 
   onChooseSuggestion(item: DeckIDDataTuple, evt: MouseEvent | KeyboardEvent): void {
-    this.onChoose?.(item, evt);
+    this.onChoose?.(isAllDecks(item) ? null : item, evt);
   }
 
   private descendants(deck: DeckIDDataTuple): string {

src/renderings/RendererRegistry.ts

@@ -0,0 +1,32 @@
+import { CommandableAssistant } from "#/declarations/Commandable";
+import { Commands } from "#/declarations/CommandNames";
+import { ExplicitDeclarationAssistant } from "#/declarations/ExplicitDeclaration";
+import { AlternateHeadingsRenderer } from "#/renderings/declarations/AlternateHeadingsRenderer";
+import { DeclarationRenderable, DeclarationRenderer, FactoryRegistryEntry } from "#/renderings/declarations/DeclarationRenderable";
+import { HeadingAndDelimiterRenderer } from "#/renderings/declarations/HeadingAndDelimiterRenderer";
+import { HeadingIsFrontRenderer } from "#/renderings/declarations/HeadingIsFrontRenderer";
+import { PageDeclarationRenderer } from "#/renderings/declarations/PageDeclarationRenderer";
+
+
+const COMMAND_RENDERERS: FactoryRegistryEntry[] = [
+    DeclarationRenderer.Factory.createEntry(Commands.Name.AlternateHeadings, AlternateHeadingsRenderer),
+    DeclarationRenderer.Factory.createEntry(Commands.Name.HeadingAndDelimiter, HeadingAndDelimiterRenderer),
+    DeclarationRenderer.Factory.createEntry(Commands.Name.HeadingIsFront, HeadingIsFrontRenderer),
+];
+
+export const RendererRegistry = {
+	tryCreate(declaration: unknown): DeclarationRenderable | null {
+
+		let r: DeclarationRenderable | null = null;
+
+		if (CommandableAssistant.is(declaration)) {
+			const entry = COMMAND_RENDERERS.find(r => r.names.includes(declaration.name));
+			r = entry ? entry.create(declaration) : null
+		}
+		else if (ExplicitDeclarationAssistant.MaybePage.is(declaration)) {
+			r = new PageDeclarationRenderer(declaration);
+		}
+
+		return r;
+	}
+};

src/renderings/content/AudioProcessor.ts

@@ -73,7 +73,7 @@ export class AudioProcessor extends ContentRendererProcessor implements ContentR
 			}
 
 			const match = this.registeredAudioItems.find(p => p.el === audioElThatStartedPlaying) ?? null;
-			Env.assert(match, "Expected to find the element.")
+			Env.assert(match !== null, "Expected to find the element.")
 			this.currentlyPlaying = match;
 		});
 
@@ -89,12 +89,12 @@ export class AudioProcessor extends ContentRendererProcessor implements ContentR
 	/**
 		* - Note: If paused because of {@link HtmlAttribute.MediaElement.Plugin.Data.LoopDelay} it is still considered playing.
 		*/
-	private currentlyPlaying: { el: HTMLAudioElement, controller: TimeLoopController } | null;
+	private currentlyPlaying: { el: HTMLAudioElement, controller: TimeLoopController } | null = null;
 
 	/**
 		* @returns `null` if no source was set.
 		*/
-	private static getPlayerInfo(param: PostProcessorParameter, el: HTMLAudioElement): AudioPlayerInfo | null {
+	private static getPlayerInfo(_param: PostProcessorParameter, el: HTMLAudioElement): AudioPlayerInfo | null {
 		Env.log.proc(`getPlayerInfo`);
 
 		const getSource = () => {
@@ -113,7 +113,7 @@ export class AudioProcessor extends ContentRendererProcessor implements ContentR
 					return "current";
 
 				case HtmlAttribute.MediaElement.Plugin.Data.SeekOnPause.Values.INITIAL:
-				default:
+				case null:
 					return "init";
 			}
 		};
@@ -465,7 +465,7 @@ class TimeLoopController extends Component {
 					Env.log.proc(`\t\tSetting playback position to ${this.info.startTime}.`);
 					this.seekTo(player, this.info.startTime);
 					break;
-				default:
+				case "current":
 					Env.log.proc(`\t\tRetaining playback position`);
 			}
 		}

src/renderings/content/ContentRenderer.ts

@@ -9,7 +9,7 @@ import { RecycleComponent } from "utils/obs/RecycleComponent";
 import { PluginSettings } from "Settings";
 import { Async } from "utils/ts";
 
-export function createRenderConfig(settings: PluginSettings): ContentProcessorConfig {
+export function createRenderConfig(_settings: PluginSettings): ContentProcessorConfig {
 	return {
 		media: {
 			preventMultiplePlayback: true,
@@ -45,7 +45,7 @@ export class ContentRenderer extends RecycleComponent {
 		this.config = config;
 	}
 
-	protected onRecycled(component: Component): void {
+	protected override onRecycled(component: Component): void {
 		Env.log.d("ContentRenderer:onRecycled");
 
 		/** These will always run, and before any custom ones. */
@@ -59,7 +59,7 @@ export class ContentRenderer extends RecycleComponent {
 		this.defaultProcessors.forEach(p => component.addChild(p));
 	}
 
-	protected onRecycling(): void {
+	protected override onRecycling(): void {
 		Env.log.d("ContentRenderer:onRecycling");
 		this.defaultProcessors = [];
 		this.customProcessors = [];
@@ -112,8 +112,7 @@ export class ContentRenderer extends RecycleComponent {
 			return;
 		}
 
-		if (processors)
+		processors.forEach(p => this.recycleComponent.addChild(p));
-			processors.forEach(p => this.recycleComponent.addChild(p));
 
 		const param = {
 			app: this.app,
@@ -151,7 +150,6 @@ export class ContentRenderer extends RecycleComponent {
 				processor.handleHtml(postParameter);
 		}
 
-		if (processors)
+		processors.forEach(p => this.recycleComponent.removeChild(p));
-			processors.forEach(p => this.recycleComponent.removeChild(p));
 	}
 }

src/renderings/content/ContentRendererProcessor.ts

@@ -1,6 +1,6 @@
 import { Env } from "env";
 import { App, Component } from "obsidian";
-import { getDoc } from "utils/obs/dom";
+import { Doc } from "utils/dom/dom";
 
 export type MediaContentProcessorConfig = {
 	preventMultiplePlayback: boolean;
@@ -74,7 +74,7 @@ export class ContentRendererPostProcessorAssistant {
 	}
 
 	public get doc() {
-		return getDoc(this.param.el);
+		return Doc.get(this.param.el);
 	}
 
 	public get el() {

src/renderings/content/VideoProcessor.ts

@@ -6,7 +6,7 @@ export class VideoProcessor extends ContentRendererProcessor implements ContentR
 		param.el.querySelectorAll("video").forEach(el => this.handleVideo(param, el));
 	}
 
-	private handleVideo(param: PostProcessorParameter, el: HTMLVideoElement) {
+	private handleVideo(_param: PostProcessorParameter, el: HTMLVideoElement) {
 		this.setDefaults(el);
 	}
 

src/renderings/declarations/AlternateHeadingsRenderer.ts

@@ -1,13 +1,17 @@
-import { DeclarationRenderer, DeclarationRenderable, DeclarationRenderAssistant } from "renderings/declarations/DeclarationRenderable";
+import { AlternateHeadingsAssistant, AlternateHeadingsDeclarable } from "#/declarations/commands/AlternateHeadings";
-import { AlternateHeadingsDeclarable, AlternateHeadingsAssistant } from "declarations/commands/AlternateHeadings";
+import { DeclarationRenderable, DeclarationRenderAssistant, DeclarationRenderer } from "#/renderings/declarations/DeclarationRenderable";
+
+const Assistant = AlternateHeadingsAssistant;
 
 export class AlternateHeadingsRenderer
 	extends DeclarationRenderer<AlternateHeadingsDeclarable>
 	implements DeclarationRenderable {
 
+	public static override canRender = (value: unknown) => Assistant.is(value);
+
 	public render(r: DeclarationRenderAssistant) {
 
-		if (!AlternateHeadingsAssistant.conforms(this.declarable) || !AlternateHeadingsAssistant.isValid(this.declarable)) {
+		if (!Assistant.isValid(this.declarable)) {
 			r.setError();
 			r.setTitle("Invalid alternate headings command");
 			r.addParagraph("Please check the entered values.");

src/renderings/declarations/CardDeclarationRenderer.ts

@@ -1,29 +0,0 @@
-import { DeclarationRenderer, DeclarationRenderable, DeclarationRenderAssistant } from "renderings/declarations/DeclarationRenderable";
-import { CardDeclarationAssistant, DefaultableCardDeclarable } from "declarations/CardDeclaration";
-
-export class CardDeclarationRenderer
-	extends DeclarationRenderer<DefaultableCardDeclarable>
-	implements DeclarationRenderable {
-
-	public render(f: DeclarationRenderAssistant) {
-
-		f.setTitle("Flashcard declaration");
-
-		const table = f.createEl("table");
-		const body = table.createEl("tbody");
-
-		const rowID = body.createEl("tr");
-		rowID.createEl("td", { text: "ID" });
-		rowID.createEl("td", {
-			text: CardDeclarationAssistant.conformsToDeclarable(this.declarable) ? this.declarable.id : ""
-		});
-
-		const rowSide = body.createEl("tr");
-		rowSide.createEl("td", { text: "Side" });
-		rowSide.createEl("td", { text: `${CardDeclarationAssistant.isFrontSide(this.declarable) ? "Front" : "Back"}` });
-
-		if (CardDeclarationAssistant.isFrontSide(this.declarable)) {
-			f.createDeckRow(body, this.declarable);
-		}
-	}
-}

src/renderings/declarations/DeclarationErrorRenderer.ts

@@ -1,14 +1,19 @@
-import { DeclarationRenderable, DeclarationRenderAssistant, DeclarationRenderer } from "renderings/declarations/DeclarationRenderable";
+import { DeclarationRenderable, DeclarationRenderAssistant } from "#/renderings/declarations/DeclarationRenderable";
-import { Declarable } from "declarations/Declaration";
+import { YamlObject } from "#/declarations/DeclarationCodec";
 
 
 export class DeclarationErrorRenderer
-	extends DeclarationRenderer<Declarable>
 	implements DeclarationRenderable {
 
 	public method?: (r: DeclarationRenderAssistant, errorMessage?: string) => void;
 	public errorMessage?: string;
 
+	private declaration: YamlObject;
+
+	constructor(declaration: YamlObject) {
+		this.declaration = declaration;
+	}
+
 	public render(r: DeclarationRenderAssistant) {
 		r.setError();
 		if (this.method) {
@@ -20,12 +25,12 @@ export class DeclarationErrorRenderer
 		}
 	}
 
-	public static invalidCardDeclaration(r: DeclarationRenderAssistant, errorMessage?: string) {
+	public static invalidCardDeclaration(r: DeclarationRenderAssistant, _errorMessage?: string) {
 		r.setTitle("Invalid card declaration");
 		r.addParagraph("Please check entered keys and values.");
 	}
 
-	public static invalidCommandDeclaration(r: DeclarationRenderAssistant, errorMessage?: string) {
+	public static invalidCommandDeclaration(r: DeclarationRenderAssistant, _errorMessage?: string) {
 		r.setTitle("Invalid declaration command");
 		r.addParagraph("Please check the entered values.");
 	}

src/renderings/declarations/DeclarationRenderChild.ts

@@ -1,18 +1,22 @@
-import { CardDeclarationAssistant } from "declarations/CardDeclaration";
+import { CommandableAssistant } from "#/declarations/Commandable";
-import { CommandDeclarationAssistant } from "declarations/CommandDeclaration";
+import { DeclarableAssistant } from "#/declarations/Declarable";
-import { Declaration } from "declarations/Declaration";
+import { DeclarationCodec } from "#/declarations/DeclarationCodec";
-import { Env } from "env";
+import { Env } from "#/env";
+import { DeclarationErrorRenderer } from "#/renderings/declarations/DeclarationErrorRenderer";
+import { DataProvider, DeclarationChangedEvent, DeclarationRenderAssistant } from "#/renderings/declarations/DeclarationRenderable";
+import { RendererRegistry } from "#/renderings/RendererRegistry";
+import { Icon } from "#/ui/constants";
 import { MarkdownRenderChild, setIcon } from "obsidian";
-import { AlternateHeadingsRenderer } from "renderings/declarations/AlternateHeadingsRenderer";
-import { CardDeclarationRenderer } from "renderings/declarations/CardDeclarationRenderer";
-import { DeclarationErrorRenderer } from "renderings/declarations/DeclarationErrorRenderer";
-import { DataProvider, DeclarationChangedEvent, DeclarationRenderable, DeclarationRenderAssistant } from "renderings/declarations/DeclarationRenderable";
-import { HeadingAndDelimiterRenderer } from "renderings/declarations/HeadingAndDelimiterRenderer";
-import { HeadingIsFrontRenderer } from "renderings/declarations/HeadingIsFrontRenderer";
-import { Icon } from "ui/constants";
 
 export class DeclarationRenderChild extends MarkdownRenderChild {
 
+	private source: string;
+	private dataProvider: DataProvider;
+
+	private titleContainer!: HTMLDivElement;
+	private titleEl!: HTMLDivElement;
+	private contentContainerEl!: HTMLDivElement;
+
 	public constructor(containerEl: HTMLElement, source: string, dataProvider: DataProvider) {
 		super(containerEl);
 
@@ -20,25 +24,31 @@ export class DeclarationRenderChild extends MarkdownRenderChild {
 		this.dataProvider = dataProvider;
 	}
 
+	public override onload(): void {
+		Env.log.d("DeclarationRenderChild:onload");
+		super.onload();
+
+		// Manual cleanup for these elements in `onunload` is not necessary because they are added directly
+		// to `containerEl`, which is managed and eventually discarded by the base class.
+		this.containerEl.addClass("callout");
+
+		this.titleContainer = this.containerEl.createDiv({ cls: "callout-title" });
+		this.titleContainer.createDiv({ cls: "callout-icon" }, (icon) => setIcon(icon, Icon.PLUGIN));
+		this.titleEl = this.titleContainer.createDiv({ cls: "callout-title-inner" });
+
+		this.contentContainerEl = this.containerEl.createDiv({ cls: "callout-content" });
+	}
+
 	public override onunload(): void {
 		Env.log.d("DeclarationRenderChild:onunload");
 		super.onunload();
 	}
 
-	private contentContainerEl: HTMLDivElement;
-	private source: string;
-	private dataProvider: DataProvider;
-
-	private titleContainer: HTMLDivElement;
-	private titleEl: HTMLDivElement;
-
 	/**
 		* @param onDomEvent DOM event registered with rendered elements such as buttons or select.
 		*/
 	public render(onDomEvent: DeclarationChangedEvent) {
 
-		this.initRender();
-
 		const r = new DeclarationRenderAssistant(
 			this.containerEl,
 			this.contentContainerEl,
@@ -49,50 +59,28 @@ export class DeclarationRenderChild extends MarkdownRenderChild {
 			onDomEvent
 		);
 
-		const declaration = Declaration.tryParseYaml(this.source, error => this.renderYamlError(r, error.message));
+		const declaration = DeclarationCodec.tryFromYaml(this.source, error => this.renderYamlError(r, error.message));
-		if (declaration === null)
+		if (declaration === null || !DeclarableAssistant.is(declaration))
 			return;
 
-		let declarationRenderer: DeclarationRenderable = new DeclarationErrorRenderer(declaration);
+		let declarationRenderer = RendererRegistry.tryCreate(declaration);
 
-		if (CommandDeclarationAssistant.conforms(declaration)) {
+		if (declarationRenderer === null) {
+			const errorRenderer = new DeclarationErrorRenderer(declaration);
 
-			if (CommandDeclarationAssistant.isNameValid(declaration)) {
+			if (CommandableAssistant.is(declaration)) {
-				if (CommandDeclarationAssistant.isHeadingAndDelimiter(declaration))
+				errorRenderer.method = DeclarationErrorRenderer.unknownCommandName;
-					declarationRenderer = new HeadingAndDelimiterRenderer(declaration);
+				errorRenderer.errorMessage = `Name: ${declaration.name}`;
-				else if (CommandDeclarationAssistant.isAlternateHeadings(declaration))
+			} else {
-					declarationRenderer = new AlternateHeadingsRenderer(declaration);
+				errorRenderer.method = DeclarationErrorRenderer.invalidCardDeclaration;
-				else if (CommandDeclarationAssistant.isHeadingIsFront(declaration))
-					declarationRenderer = new HeadingIsFrontRenderer(declaration);
 			}
 
-			if (declarationRenderer instanceof DeclarationErrorRenderer) {
+			declarationRenderer = errorRenderer;
-				declarationRenderer.method = DeclarationErrorRenderer.unknownCommandName;
-				declarationRenderer.errorMessage = `Name: ${declaration.name}`;
-			}
-		}
-		else {
-			if (CardDeclarationAssistant.conformsToDefaultable(declaration))
-				declarationRenderer = new CardDeclarationRenderer(declaration);
-
-			if (declarationRenderer instanceof DeclarationErrorRenderer)
-				declarationRenderer.method = DeclarationErrorRenderer.invalidCardDeclaration;
 		}
 
 		declarationRenderer.render(r);
 	}
 
-	private initRender() {
-		this.containerEl.addClass("callout");
-
-		this.titleContainer = this.containerEl.createDiv({ cls: "callout-title" });
-		this.titleContainer.createDiv({ cls: "callout-icon" }, (icon) => setIcon(icon, Icon.PLUGIN));
-		this.titleEl = this.titleContainer.createDiv({ cls: "callout-title-inner" });
-
-		this.contentContainerEl = this.containerEl.createDiv({ cls: "callout-content" });
-		return this.contentContainerEl;
-	}
-
 	private renderYamlError(r: DeclarationRenderAssistant, errorMessage?: string) {
 		r.setError();
 		r.setTitle("Invalid format entered");

src/renderings/declarations/DeclarationRenderable.ts

@@ -1,35 +1,63 @@
-import { DeckIDDataTuple } from "data/DataStore";
+import { DeckData, DeckIDDataTuple } from "#/data/DataStore";
-import { DeckableDeclarable, Declarable } from "declarations/Declaration";
+import { DeckID } from "#/data/FullID";
+import { DeckableDeclarable } from "#/declarations/Collectionable";
+import { Declarable } from "#/declarations/Declarable";
+import { HtmlTag } from "#/utils/dom/constants";
+import { TableCreator } from "#/utils/dom/table";
 import { Component, setIcon } from "obsidian";
-import { UIAssistant } from "ui/UIAssistant";
 
 export type DeclarationChangedType = "deckAdded" | "deckChanged";
 export type DeclarationChangedEvent = (declaration: DeckableDeclarable, type: DeclarationChangedType, selectEl: HTMLSelectElement) => void;
 
 export interface DataProvider {
 	getAllDecks: () => DeckIDDataTuple[];
+	getDeck: (id: DeckID) => DeckData | null;
 };
 
 export interface DeclarationRenderable {
 	render(r: DeclarationRenderAssistant): void;
 }
 
+export interface FactoryRegistryEntry {
+	names: readonly string[];
+	create: (d: unknown) => DeclarationRenderable | null;
+}
+
 export abstract class DeclarationRenderer<T extends Declarable> {
 	protected declarable: T;
-	public constructor(declarable: T) {
+
-		this.declarable = declarable;
+	public constructor(declarable: T) { this.declarable = declarable; }
-	}
+
+	/**
+		* @abstract
+		* @returns Whether the renderer can render the given value.
+		*/
+	public static canRender = (_value: unknown): boolean => { throw new Error("Not implemented"); }
+
+	public static readonly Factory = {
+		createEntry: <T extends Declarable>(
+			names: readonly string[],
+			RendererClass: {
+				new(declarable: T): DeclarationRenderable;
+				canRender(value: unknown): value is T;
+			}): FactoryRegistryEntry => {
+			return {
+				names,
+				create: (declarable) => RendererClass.canRender(declarable) ? new RendererClass(declarable) : null
+			};
+		}
+	};
 }
 
 export class DeclarationRenderAssistant {
 
-	private containerEl: HTMLElement;
+	private readonly containerEl: HTMLElement;
-	protected contentContainerEl: HTMLDivElement;
+	private readonly contentContainerEl: HTMLDivElement;
-	private titleContainer: HTMLDivElement;
+	private readonly titleContainer: HTMLDivElement;
-	private titleEl: HTMLDivElement;
+	private readonly titleEl: HTMLDivElement;
-	private component: Component;
+	private readonly component: Component;
-	private dataProvider: DataProvider;
+	private readonly dataProvider: DataProvider;
-	protected onDomEvent: DeclarationChangedEvent
+	private readonly onDomEvent: DeclarationChangedEvent;
 
 	public constructor(
 		containerEl: HTMLElement,
@@ -81,15 +109,19 @@ export class DeclarationRenderAssistant {
 		});
 	}
 
+	public createTable() {
+		return TableCreator.create(this.contentContainerEl);
+	}
+
 	public createDeckRow(body: HTMLTableSectionElement, declaration: DeckableDeclarable) {
 		const rowDeck = body.createEl("tr");
 		rowDeck.createEl("td", { text: "Deck" });
 		const tdDropdown = rowDeck.createEl("td", { cls: "select-deck-cell" });
 
-		const deckSelectEl = tdDropdown.createEl("select", { cls: "dropdown" }, (el) => {
+		const deckSelectEl = tdDropdown.createEl(HtmlTag.SELECT.NAME, { cls: "dropdown" }, (el) => {
-			el.createEl("option", {
+			el.createEl(HtmlTag.SELECT.OPTION.NAME, {
 				text: "None",
-				value: UIAssistant.DECK_ID_NONE,
+				value: HtmlTag.SELECT.OPTION.Values.NONE,
 			});
 		});
 
@@ -103,11 +135,11 @@ export class DeclarationRenderAssistant {
 		const decks = this.dataProvider.getAllDecks();
 		if (decks.length > 0) {
 			decks.forEach(deck => {
-				deckSelectEl.createEl("option", {
+				deckSelectEl.createEl(HtmlTag.SELECT.OPTION.NAME, {
 					text: deck.data.n,
 					value: deck.id,
 				}, (el) => {
-					el.selected = declaration?.deckID === deck.id;
+					el.selected = declaration.deckID === deck.id;
 				});
 			});
 			this.component.registerDomEvent(deckSelectEl, "change", () => this.onDomEvent(declaration, "deckChanged", deckSelectEl));

src/renderings/declarations/HeadingAndDelimiterRenderer.ts

@@ -1,13 +1,18 @@
-import { DeclarationRenderer, DeclarationRenderable, DeclarationRenderAssistant } from "renderings/declarations/DeclarationRenderable";
+import { HeadingAndDelimiterAssistant, HeadingAndDelimiterDeclarable } from "#/declarations/commands/HeadingAndDelimiter";
-import { HeadingAndDelimiterAssistant, HeadingAndDelimiterDeclarable } from "declarations/commands/HeadingAndDelimiter";
+import { DeclarationRenderable, DeclarationRenderAssistant, DeclarationRenderer } from "#/renderings/declarations/DeclarationRenderable";
+import { UNARY_UNION_SUPPRESS } from "#/utils/ts";
+
+const Assistant = HeadingAndDelimiterAssistant;
 
 export class HeadingAndDelimiterRenderer
 	extends DeclarationRenderer<HeadingAndDelimiterDeclarable>
 	implements DeclarationRenderable {
 
+	public static override canRender = (value: unknown) => Assistant.is(value);
+
 	public render(r: DeclarationRenderAssistant) {
 
-		if (!HeadingAndDelimiterAssistant.conforms(this.declarable) || !HeadingAndDelimiterAssistant.isValid(this.declarable)) {
+		if (!HeadingAndDelimiterAssistant.is(this.declarable) || !HeadingAndDelimiterAssistant.isValid(this.declarable)) {
 			r.setError();
 			r.setTitle("Invalid alternate headings command");
 			r.addParagraph("Please check the entered values.");
@@ -22,10 +27,16 @@ export class HeadingAndDelimiterRenderer
 					text: `Automatically generate a card for every heading ${this.declarable.level} levels below this one.`
 				}),
 				el.createEl("li", undefined, (el) => {
-					if (this.declarable.delimiter === "horizontal rule") {
+					switch (this.declarable.delimiter) {
-						el.appendText("The back side will begin after the first ");
+						case UNARY_UNION_SUPPRESS:
-						el.createEl("a", { text: "horizontal rule", href: "https://daringfireball.net/projects/markdown/syntax#hr" });
+							break;
-						el.appendText(" within the heading’s section.");
+
+						case "horizontal rule": {
+							el.appendText("The back side will begin after the first ");
+							el.createEl("a", { text: "horizontal rule", href: "https://daringfireball.net/projects/markdown/syntax#hr" });
+							el.appendText(" within the heading’s section.");
+							break;
+						}
 					}
 				})
 			];
@@ -40,7 +51,7 @@ export class HeadingAndDelimiterRenderer
 		});
 
 		body.createEl("tr", undefined, (el) => {
-			el.createEl("td", { text: "Side delimiter" });
+			el.createEl("td", { text: "Page delimiter" });
 			el.createEl("td", { text: "The first horizontal rule" });
 		});
 

src/renderings/declarations/HeadingIsFrontRenderer.ts

@@ -1,13 +1,17 @@
-import { HeadingIsFrontAssistant, HeadingIsFrontDeclarable } from "declarations/commands/HeadingIsFront";
+import { HeadingIsFrontAssistant, HeadingIsFrontDeclarable } from "#/declarations/commands/HeadingIsFront";
-import { DeclarationRenderable, DeclarationRenderAssistant, DeclarationRenderer } from "renderings/declarations/DeclarationRenderable";
+import { DeclarationRenderable, DeclarationRenderAssistant, DeclarationRenderer } from "#/renderings/declarations/DeclarationRenderable";
+
+const Assistant = HeadingIsFrontAssistant;
 
 export class HeadingIsFrontRenderer
 	extends DeclarationRenderer<HeadingIsFrontDeclarable>
 	implements DeclarationRenderable {
 
+	public static override canRender = (value: unknown) => Assistant.is(value);
+
 	public render(r: DeclarationRenderAssistant) {
 
-		if (!HeadingIsFrontAssistant.conforms(this.declarable) || !HeadingIsFrontAssistant.isValid(this.declarable)) {
+		if (!HeadingIsFrontAssistant.is(this.declarable) || !HeadingIsFrontAssistant.isValid(this.declarable)) {
 			r.setError();
 			r.setTitle("Invalid heading is front command");
 			r.addParagraph("Please check the entered values.");

src/renderings/declarations/PageDeclarationRenderer.ts

@@ -0,0 +1,83 @@
+import { DefaultableCardDeclarable, ExplicitDeclarationAssistant, MaybePageDeclarable } from "#/declarations/ExplicitDeclaration";
+import { DeclarationRenderable, DeclarationRenderAssistant, DeclarationRenderer } from "#/renderings/declarations/DeclarationRenderable";
+import { Str } from "utils/ts";
+
+const Assistant = ExplicitDeclarationAssistant;
+
+export class PageDeclarationRenderer
+	extends DeclarationRenderer<MaybePageDeclarable>
+	implements DeclarationRenderable {
+
+	public render(r: DeclarationRenderAssistant) {
+
+		if (!Assistant.MaybePage.isValid(this.declarable)) {
+			PageDeclarationRenderer.renderError(r, "`side` must be a string, number, or boolean.");
+		}
+		else {
+			if (Assistant.Defaultable.is(this.declarable)) {
+				PageDeclarationRenderer.renderDefaultDeclarable(r, this.declarable);
+			}
+			else {
+				PageDeclarationRenderer.renderError(r, "`id` and `side` must be text.");
+			}
+		}
+	}
+
+	private static renderError(r: DeclarationRenderAssistant, msg?: string) {
+		r.setError();
+		r.setTitle("Invalid page declaration");
+		if (msg !== undefined)
+			r.addParagraph(msg);
+	}
+
+	private static renderDefaultDeclarable(r: DeclarationRenderAssistant, declarable: DefaultableCardDeclarable) {
+
+		if (!Assistant.Defaultable.isValid(declarable)) {
+			PageDeclarationRenderer.renderError(r);
+			r.addBulletList(["`side` must be f, front, b or back", "`id` must be a string"]);
+			return;
+		}
+
+		const completeDeclarable = Assistant.is(declarable) ? declarable : null;
+		const validCompleteDeclarable = completeDeclarable !== null && Assistant.isValid(completeDeclarable) ? completeDeclarable : null;
+
+		if (Assistant.canComplete(declarable) || validCompleteDeclarable !== null) {
+			const isFront = Assistant.isFrontSide(declarable);
+
+			r.setTitle("Page declaration");
+
+			let idValue = validCompleteDeclarable !== null ? validCompleteDeclarable.id : declarable.id;
+
+			if (Assistant.PropertyEq.optionalNullOrString(idValue, (str) => !Str.isNonEmpty(str))) {
+				idValue = isFront ? "Generating…" : Str.EMPTY;
+				if (!isFront)
+					r.addParagraph("`id` is missing.");
+			}
+
+			r.createTable().addBody(row => {
+
+				row.add((col) => {
+					col.add({ text: "ID" });
+					col.add({ text:  idValue });
+				});
+
+				row.add((col) => {
+					col.add({ text: "Side" });
+					col.add({ text: `${isFront ? "Front" : "Back"}` });
+				});
+
+				if (isFront) {
+					r.createDeckRow(row.sectionEl, declarable);
+				}
+			});
+		}
+		else { // validCompleteDeclarable === null
+			PageDeclarationRenderer.renderError(r);
+
+			if (Assistant.isFrontSide(declarable))
+				r.addParagraph("`id` should be a 10 character string.");
+			else
+				r.addParagraph("Add `id` that matches the front side.");
+		}
+	}
+}

src/scheduling/Fsrs.ts

@@ -1,4 +1,3 @@
-import { Env } from "env";
 import { FsrsSchedulerConfig } from "scheduling/types";
 import { Card, createEmptyCard, default_enable_fuzz, default_enable_short_term, default_learning_steps, default_maximum_interval, default_relearning_steps, default_request_retention, fsrs, FSRS, generatorParameters, Grade, RecordLogItem } from "ts-fsrs";
 
@@ -15,7 +14,6 @@ export class Fsrs {
 	}
 
 	private static createFromConfig(config: FsrsSchedulerConfig) {
-		Env.assert(config);
 
 		const params = generatorParameters({
 			request_retention: default_request_retention,

src/ui/SettingTab.ts

@@ -29,7 +29,7 @@ export class SettingTab extends PluginSettingTab {
 			.addText((component) => {
 				component.setValue(settings.uiPrefix);
 				component.onChange(async (value) => {
-					settings.uiPrefix = value;
+					settings.uiPrefix = value.trim();
 					await this.settingsManager.save();
 				});
 			});
@@ -46,7 +46,7 @@ export class SettingTab extends PluginSettingTab {
 			});
 	}
 
-	public hide(): void {
+	public override hide(): void {
 		this.settingsManager.unregisterOnChangedCallback(this.onChangedCallback);
 	}
 }

src/ui/UIAssistant.ts

@@ -1,18 +1,11 @@
-import { DeckIDDataTuple } from "data/DataStore";
-import { DeckID } from "data/FullID";
 import { App, MarkdownView, Menu, MenuItem, Notice } from "obsidian";
 import { SettingsManager } from "Settings";
-import { Icon, PLUGIN_NAME } from "ui/constants";
+import { Icon } from "ui/constants";
+import { Str } from "utils/ts";
 
 
 export class UIAssistant {
 
-  /**
-   * Deck ID to use to represent unassigned deck when a string is required to identify UI elements.
-   * For example string values in DOM elements.
-   */
-  public static readonly DECK_ID_NONE: DeckID = "0000";
-
   private settingsManager: SettingsManager;
 
   constructor(settingsManager: SettingsManager) {
@@ -21,10 +14,7 @@ export class UIAssistant {
 
   public contextulize(title: string) {
     const contextPrefix = this.settingsManager.settings.uiPrefix;
-    if (contextPrefix !== undefined)
+    return Str.isNonEmpty(contextPrefix) ? `${contextPrefix}: ${title}` : title;
-      return contextPrefix ? `${contextPrefix}: ${title}` : title;
-    else
-      return `${PLUGIN_NAME}: ${title}`;
   }
 
   public addMenuItem(menu: Menu, title: string, options?: {
@@ -33,8 +23,8 @@ export class UIAssistant {
     icon?: string,
     prefix?: boolean,
     isLabel?: boolean,
-    onClick?: (evt: MouseEvent | KeyboardEvent) => any
+    onClick?: (evt: MouseEvent | KeyboardEvent) => void,
-    callback?: (item: MenuItem) => any,
+    callback?: (item: MenuItem) => void,
   }): Menu {
     const {
       callback,
@@ -42,7 +32,7 @@ export class UIAssistant {
 
     menu.addItem(item => {
       this.configureMenuItem(item, title, options);
-      callback?.(item);
+			callback?.(item);
     });
 
     return menu;
@@ -54,7 +44,7 @@ export class UIAssistant {
     icon?: string,
     prefix?: boolean,
     isLabel?: boolean,
-    onClick?: (evt: MouseEvent | KeyboardEvent) => any
+    onClick?: (evt: MouseEvent | KeyboardEvent) => void,
   }): MenuItem {
     const {
       section,
@@ -103,21 +93,11 @@ export class UIAssistant {
     return notice;
   }
 
-  public static allDecksOptionItem(): DeckIDDataTuple {
-    return {
-      id: UIAssistant.DECK_ID_NONE,
-      data: {
-        n: "All Decks",
-        p: []
-      }
-    };
-  }
-
   public static isInInLivePreview(app: App) {
     const markdownView = app.workspace.getActiveViewOfType(MarkdownView)
     if (!markdownView)
       return false;
     const state = markdownView.getState();
-    return state ? state.mode == "source" && state.source == false : false;
+    return state["mode"] == "source" && state["source"] == false;
   }
 }

src/utils/datetime.ts

@@ -1,5 +1,6 @@
 import { Env } from "env";
 // Make sure you're doing import { moment} from 'obsidian' so that you don't import another copy — https://docs.obsidian.md/oo24/plugin#Performance
+// Regarding use of `@ts-expect-error`: Obsidian's recommended import style (import { moment } from 'obsidian') is typed as a namespace and is flagged as "not callable" by TypeScript 6.0's stricter checks. Instead of setting `esModuleInterop` to `true` in `tsconfig` just use  `@ts-expect-error` here.
 import { moment } from "obsidian"; // TODO: Use Luxon
 import { Str } from "utils/ts";
 // @ts-expect-error
@@ -9,16 +10,20 @@ const TIME_FORMAT = "LT";
 const DATE_FORMAT = "MMM D, LT";
 
 export const DateTime = {
+	// @ts-expect-error
 	toTimeString: (date: Date) => moment(date).format(TIME_FORMAT),
+	// @ts-expect-error
 	toString: (date: Date) => moment(date).format(DATE_FORMAT),
 
 	dateStringFromIso: (iso8601: string): string => {
 		Env.assert(!Str.is(iso8601 as unknown), "Expected an ISO string.");
+		// @ts-expect-error
 		return moment(iso8601).format(DATE_FORMAT);
 	},
 
 	dateFromIso: (iso8601: string): Date => {
 		Env.assert(!Str.is(iso8601 as unknown), "Expected an ISO string.");
+		// @ts-expect-error
 		return moment(iso8601).toDate();
 	},
 

src/utils/dom/constants.ts

@@ -1,5 +1,19 @@
+import { Str } from "#/utils/ts";
+
 export const HtmlTag = {
 	SPAN: "span",
+	SELECT: {
+		NAME: "select",
+		OPTION: {
+			NAME: "option",
+			Values: {
+				/** Represents an empty option, used as a placeholder or for no selection. */
+				NONE: Str.EMPTY,
+			},
+			isNone: (value: string): boolean => value === Str.EMPTY,
+			select: (el: HTMLOptionElement) => el.selected = true,
+		}
+	}
 } as const;
 
 export const HtmlAttribute = {
@@ -23,7 +37,7 @@ export const HtmlAttribute = {
 		Controls: {
 			NAME: "controls",
 			Values: {
-				DISPLAY: ""
+				DISPLAY: Str.EMPTY
 			}
 		},
 		/** The controlsList property of an HTMLMediaElement (like <video> or <audio>) allows you to control which built-in playback controls the user agent (browser) should display. */
@@ -39,7 +53,7 @@ export const HtmlAttribute = {
 		Loop: {
 			NAME: "loop",
 			Values: {
-				DISPLAY: ""
+				DISPLAY: Str.EMPTY
 			}
 		},
 		// https://developer.mozilla.org/en-US/docs/Web/API/HTMLMediaElement/preload

src/utils/dom/dom.ts

@@ -0,0 +1,44 @@
+// Provided by Obsidian:
+// On `Element`: `addClass`, `doc`, `removeClass`, `hasClass`, `toggleClass`, `win`
+
+
+export const Doc = {
+	/** Returns the document that the given element is located in. */
+	get: (el: HTMLElement) => el.doc,
+}
+
+export const El = {
+	setAttribute: (el: HTMLElement, name: string, value: string) => {
+		//If the attribute already exists, the value is updated; otherwise a new attribute is added with the specified name and value.
+		el.setAttribute(name, value);
+	},
+	removeAttribute: (el: HTMLElement, name: string) => {
+		el.removeAttribute(name);
+	},
+
+	Cls: {
+		add: (el: HTMLElement | undefined, className: string) => {
+			if (el !== undefined && !el.hasClass(className))
+				el.addClass(className);
+		},
+		remove: (el: HTMLElement | undefined, className: string) => {
+			if (el !== undefined && el.hasClass(className))
+				el.removeClass(className);
+		},
+		has: (el: HTMLElement | undefined, className: string) => {
+			return el !== undefined && el.hasClass(className);
+		},
+		toggle: (el: HTMLElement | undefined, className: string, value: boolean) => {
+			el?.toggleClass(className, value);
+		},
+	} as const,
+} as const;
+
+export const Win = {
+	/**
+		* Use `element.win` and `element.doc` to get the window/document that your Dom element is located in.
+		*
+		* `activeWindow`/`Document` refers to the current focused window which might not be the same one your element is in.
+		*/
+	get: (el: HTMLElement) => el.win,
+}

src/utils/dom/table.ts

@@ -1,3 +1,9 @@
+export class TableCreator {
+	public static create(parent: HTMLElement): TableSectionCreator {
+		return new TableSectionCreator(parent.createEl("table"));
+	}
+}
+
 export class TableSectionCreator {
 	public readonly tableEl: HTMLTableElement;
 
@@ -5,22 +11,22 @@ export class TableSectionCreator {
 		this.tableEl = tableEl;
 	}
 
-	public setHeader(cb: (rowCreator: TableRowCreator) => void) {
+	public setHeader(cb?: (rowCreator: TableRowCreator) => void): TableRowCreator {
 		return this.create("thead", cb);
 	}
 
 	/** It is possible to have multiple <tbody> elements in the same table. */
-	public addBody(cb: (rowCreator: TableRowCreator) => void) {
+	public addBody(cb?: (rowCreator: TableRowCreator) => void): TableRowCreator {
 		return this.create("tbody", cb);
 	}
 
-	public setFooter(cb: (rowCreator: TableRowCreator) => void) {
+	public setFooter(cb?: (rowCreator: TableRowCreator) => void): TableRowCreator {
 		return this.create("tfoot", cb);
 	}
 
-	private create(tag: "thead" | "tbody" | "tfoot", cb: (rowCreator: TableRowCreator) => void) {
+	private create(tag: "thead" | "tbody" | "tfoot", cb?: (rowCreator: TableRowCreator) => void) {
 		const r = new TableRowCreator(this.tableEl.createEl(tag), tag === "thead");
-		cb(r);
+		cb?.(r);
 		return r;
 	}
 }

src/utils/obs/DomState.ts

@@ -0,0 +1,102 @@
+import { El } from "#/utils/dom/dom";
+import { CssClass } from "#/utils/obs/constants";
+import { Arr, Str } from "#/utils/ts";
+import { Plugin } from "obsidian";
+
+type SettingsChangeCallback = (added: string[], removed: string[]) => void;
+
+interface Subscriber {
+	callback: SettingsChangeCallback;
+	classes: string[] | null;
+}
+
+export class DomState {
+	private static observer: MutationObserver | null = null;
+	private static subscribers: Subscriber[] = [];
+	private static doc: Document | undefined;
+
+	/**
+		* Call from `onload` of the plugin.
+		* @param plugin
+		* @param doc Document of the main window.
+		*/
+	public static init(plugin: Plugin, doc: Document) {
+		DomState.doc = doc;
+		plugin.register(() => DomState.unobserve());
+	}
+
+	public static deinit() {
+		Arr.clear(DomState.subscribers);
+		DomState.unobserve();
+	}
+
+	public static subscribe(callback: SettingsChangeCallback, classes: string[] | null = null) {
+		DomState.subscribers.push({ callback, classes });
+		if (DomState.subscribers.length === 1)
+			DomState.observe();
+	}
+
+	public static unsubscribe(callback: SettingsChangeCallback) {
+		DomState.subscribers = DomState.subscribers.filter(s => s.callback !== callback);
+		if (DomState.subscribers.length === 0)
+			DomState.unobserve();
+	}
+
+	private static observe() {
+		const doc = DomState.docOrThrow;
+
+		DomState.observer = new MutationObserver(DomState.onMutation);
+		DomState.observer.observe(doc.body, { attributeFilter: ["class"], attributeOldValue: true });
+	}
+
+	private static onMutation = (mutations: MutationRecord[]) => {
+		const doc = DomState.docOrThrow;
+
+		for (const mutation of mutations) {
+			const oldClasses = new Set((mutation.oldValue ?? Str.EMPTY).split(Str.SPACE).filter(Boolean));
+			const newClasses = new Set(doc.body.className.split(Str.SPACE).filter(Boolean));
+
+			const added = [...newClasses].filter(c => !oldClasses.has(c));
+			const removed = [...oldClasses].filter(c => !newClasses.has(c));
+
+			if (added.length === 0 && removed.length === 0)
+				continue;
+
+			for (const subscriber of DomState.subscribers) {
+				if (subscriber.classes === null) {
+					subscriber.callback(added, removed);
+				} else {
+					const filteredAdded = added.filter(c => subscriber.classes!.includes(c));
+					const filteredRemoved = removed.filter(c => subscriber.classes!.includes(c));
+					if (filteredAdded.length > 0 || filteredRemoved.length > 0) {
+						subscriber.callback(filteredAdded, filteredRemoved);
+					}
+				}
+			}
+		}
+	}
+
+	private static unobserve() {
+		DomState.observer?.disconnect();
+		DomState.observer = null;
+	}
+
+	private static get docOrThrow() {
+		if (DomState.doc === undefined)
+			throw new Error(`${DomState.name} not initiated.`);
+		return DomState.doc;
+	}
+
+	public static readonly UserSetting = {
+		/** See also {@link InternalApi.getConfig} */
+		get isAutoFullScreenEnabled(): boolean {
+			return El.Cls.has(DomState.docOrThrow.body, CssClass.Body.Setting.AUTO_FULL_SCREEN);
+		},
+	} as const ;
+
+	public static readonly Interface = {
+		isNavigationHidden(doc: Document | undefined = DomState.docOrThrow): boolean {
+			return El.Cls.has(doc.body, CssClass.Body.Interface.IS_HIDDEN_NAV);
+		},
+	} as const ;
+}

src/utils/obs/FileParser.ts

@@ -1,4 +1,5 @@
 import { App, CacheItem, HeadingCache, Pos, SectionCache, TFile } from "obsidian";
+import { UNARY_UNION_SUPPRESS } from "#/utils/ts";
 
 interface FileParserErrorOptions extends ErrorOptions {
 	type: "file cache unavailable";
@@ -24,6 +25,11 @@ export class FileParserError extends Error {
 	}
 }
 
+export type OffsetRange = {
+    start: number;
+    end: number;
+};
+
 /** A part of a file's content delimited by two {@link SectionCache} */
 export type SectionRange = {
 	/** If `null`, starts at the beginning.*/
@@ -36,7 +42,7 @@ export type CodeBlockInfo = {
 	/** May be an empty string if language is not specified. */
 	language: string;
 	/** The location of the content relative to the first tick of the block. */
-	location: { start: number, end: number};
+	location: OffsetRange;
 	content: string;
 }
 
@@ -63,10 +69,13 @@ const FrontmatterSection: ExternalSectionCache = {
 * Sections of the file that are not part of the actual Markdown.
 */
 interface ExternalSectionCache extends SectionCache {
-	externalType: "frontmatter" //| "backmatter"
+	externalType: "frontmatter" | typeof UNARY_UNION_SUPPRESS //| "backmatter"
 }
 
-/** Provides a set of common helpers for interpreting the structure and metadata of markdown files. */
+/**
+	* Provides a set of common helpers for interpreting the structure and metadata of markdown files.
+	* @abstract
+	*/
 export abstract class FileParser {
 
 	protected static readonly SECTION_TYPE_HEADING = "heading";
@@ -125,7 +134,6 @@ export abstract class FileParser {
 	}
 
 	/**
-	 * @todo This method does not support code blocks that start with four characters.
 	 * @param source The code block including the three ticks at the beginning and end. See {@link extractContentFromSection}.
 	 * @returns `null` is {@link source} is not a code block.
 	 */

src/utils/obs/InteractionAssistant.ts

@@ -0,0 +1,221 @@
+import { Env } from "#/env";
+import { El } from "#/utils/dom/dom";
+import { CssClass } from "#/utils/obs/constants";
+import { DomState } from "#/utils/obs/DomState";
+import { InternalApi } from "#/utils/obs/internal";
+import { ViewAssistant } from "#/utils/obs/ViewAssistant";
+import { App, Component, debounce } from "obsidian";
+
+
+export class InteractionAssistant {
+
+	private component: Component;
+	private viewAssistant: ViewAssistant;
+	private doc: Document | undefined;
+	private app: App;
+
+	constructor(app: App, component: Component, viewAssistant: ViewAssistant) {
+		this.app = app;
+		this.component = component;
+		this.viewAssistant = viewAssistant;
+	}
+
+	public init(doc: Document) {
+		Env.assert(this.viewAssistant.isInitialized, `${ViewAssistant.name} must be initialized before ${InteractionAssistant.name}`);
+
+		this.doc = doc;
+		this.component.registerDomEvent(this.viewAssistant.scrollContainer, "scroll", this.onScroll);
+		this.scroll.resetState();
+		this.ui.isNavigationHidden = DomState.Interface.isNavigationHidden(this.docOrThrow);
+
+		DomState.subscribe(this.onStateChange, [
+			CssClass.Body.Setting.AUTO_FULL_SCREEN,
+			CssClass.Body.Platform.IS_PHONE,
+			CssClass.Body.Interface.IS_HIDDEN_NAV,
+		]);
+	}
+
+	public get isInitialized(): boolean {
+		return this.doc !== undefined;
+	}
+
+	public deinit() {
+		DomState.unsubscribe(this.onStateChange);
+		this.ui.showNavigation(true);
+		this.doubleTap.clearMouseDownTimer();
+		this.doc = undefined;
+	}
+
+	public registerDoubleClick(el: HTMLElement, onDoubleTap: () => void) {
+		this.doubleTap.reg(el, onDoubleTap);
+	}
+
+	public nextScrollIsProgrammatic() {
+		this.scroll.nextScrollIsProgrammatic = true;
+	}
+
+	private get docOrThrow() {
+		if (this.doc === undefined)
+			throw new Error(`${InteractionAssistant.name} not initiated.`);
+		return this.doc;
+	}
+
+	private onStateChange = (added: string[], removed: string[]) => {
+
+		if (added.includes(CssClass.Body.Setting.AUTO_FULL_SCREEN)) {
+			this.scroll.previousScrollTop = 0;
+			this.ui.isAutoFullScreenEnabled = true;
+		}
+		else if (removed.includes(CssClass.Body.Setting.AUTO_FULL_SCREEN)) {
+			// Full screen disabled, make sure navigation is shown.
+			this.ui.showNavigation(true);
+			this.ui.isAutoFullScreenEnabled = false;
+		}
+
+		if (added.includes(CssClass.Body.Interface.IS_HIDDEN_NAV))
+			this.ui.isNavigationHidden = true;
+		else if (removed.includes(CssClass.Body.Interface.IS_HIDDEN_NAV))
+			this.ui.isNavigationHidden = false;
+
+		if (DomState.UserSetting.isAutoFullScreenEnabled) {
+			// Make sure that navigation is shown intitally when screen size changes e.g. from tablet to phone.
+			if (added.includes(CssClass.Body.Platform.IS_PHONE) || removed.includes(CssClass.Body.Platform.IS_PHONE))
+				this.ui.showNavigation(true);
+		}
+	};
+
+	private onScroll = () => {
+		if (!this.isInitialized)
+			return;
+
+		this.scroll.on();
+	}
+
+	private readonly ui = {
+		isAutoFullScreenEnabled: DomState.UserSetting.isAutoFullScreenEnabled,
+		isNavigationHidden: false, // Needs doc. Set in init.
+
+		showNavigation: (show: boolean) => {
+			if (show === !this.ui.isNavigationHidden)
+				return;
+
+			try {
+				// This will hide the status bar as well.
+				InternalApi.hideNav(this.app, !show);
+			}
+			finally {
+				// This is a fallback in case the above call fails. This hides the navigation controls but not the status bar.
+				const isHidden = DomState.Interface.isNavigationHidden(this.docOrThrow); // The callback has not yet triggered, so we need to look at DOM directly.
+				if (show && isHidden || !show && !isHidden)
+					El.Cls.toggle(this.docOrThrow.body, CssClass.Body.Interface.IS_HIDDEN_NAV, !show);
+			}
+		}
+	};
+
+	private readonly scroll = {
+
+		on() {
+			if (this.nextScrollIsProgrammatic) {
+				this.nextScrollIsProgrammatic = false;
+				return;
+			}
+
+			this.onScroll();
+		},
+
+		onScroll: () => {
+			if (this.ui.isAutoFullScreenEnabled) {
+
+				/* Obsidians implementation:
+					e.prototype.onScroll = function(e, t) {
+						var n, i = null !== (n = this.scrollTops.get(e)) && void 0 !== n ? n : 0;
+						if (this.scrollTops.set(e, t),
+						Yl.isPhone && !Yl.mobileSoftKeyboardVisible && this.app.vault.getConfig("autoFullScreen")) {
+								var r = t - i;
+								t < .1 && i < .1 || Math.abs(r) < .125 || (r > 0 ? this.hideNavigation() : this.restoreNavigation())
+						}
+					}
+			 */
+
+				const maxScroll = this.viewAssistant.scrollContainer.scrollHeight - this.viewAssistant.scrollContainer.clientHeight;
+				const currentScrollTop = Math.min(Math.max(0, this.viewAssistant.scrollContainer.scrollTop), maxScroll);
+				const delta = currentScrollTop - this.scroll.previousScrollTop;
+				const previousScrollTop = this.scroll.previousScrollTop;
+				this.scroll.previousScrollTop = currentScrollTop;
+
+				// 0.125 is probably just guarding against floating point values that are technically non-zero but represent no real movement.
+				if (!(currentScrollTop < 0.1 && previousScrollTop < 0.1) && Math.abs(delta) >= 0.125)
+					this.ui.showNavigation(delta <= 0);
+			}
+			else {
+				this.ui.showNavigation(true);
+			}
+		},
+
+		handleScrollDebounced: debounce(() => {
+			this.scroll.onScroll();
+		}, 50, true),
+
+		previousScrollTop: 0,
+
+		/** Used when a scroll event will be triggered programmatically to disable scroll handling temporarily. */
+		nextScrollIsProgrammatic: false,
+
+		resetState() {
+			this.previousScrollTop = 0;
+			this.nextScrollIsProgrammatic = false;
+		},
+	};
+
+
+	/**
+		* Obsidian adds code so that navigation is restored when user taps once.
+		* This method catches the `mousedown` event and stops its propagation if navigation is hidden.
+		* It then re-dispatches the event after a short delay if no double tap occurred.
+		*/
+	private readonly doubleTap = {
+
+		reg: (el: HTMLElement, onDoubleTap: () => void) => {
+			/*
+			Obsidian adds this code so that navigation is restored when user taps once.
+			```
+			 window.addEventListener("mousedown", (function() {
+					return t.restoreNavigation(!0)
+				}
+			```
+			Catch it before it propagates to the window.
+			*/
+			this.component.registerDomEvent(el, 'mousedown', (e) => {
+				if (DomState.Interface.isNavigationHidden(this.docOrThrow)) {
+					e.stopPropagation();
+					this.doubleTap.dispatchMouseDown(e);
+				}
+			});
+
+			this.component.registerDomEvent(el, "dblclick", () => {
+				this.doubleTap.clearMouseDownTimer();
+				onDoubleTap();
+			});
+		},
+
+		dispatchMouseDown: (e: MouseEvent) => {
+			this.doubleTap.clearMouseDownTimer();
+
+			const win = this.docOrThrow.win;
+			this.doubleTap.mouseDownTimer = win.setTimeout(() => {
+				this.doubleTap.mouseDownTimer = null;
+				win.dispatchEvent(new MouseEvent('mousedown', e));
+			}, 300);
+
+		},
+
+		clearMouseDownTimer: () => {
+			if (this.doubleTap.mouseDownTimer !== null) {
+				this.docOrThrow.win.clearTimeout(this.doubleTap.mouseDownTimer);
+				this.doubleTap.mouseDownTimer = null;
+			}
+		},
+
+		mouseDownTimer: null as number | null,
+	};
+}

src/utils/obs/RecycleComponent.ts

@@ -21,19 +21,19 @@ export abstract class RecycleComponent extends Component {
 		return super.addChild(component);
 	}
 
-  public override removeChild<T extends Component>(component: T): T {
+	public override removeChild<T extends Component>(component: T): T {
-  	Env.assert(false);
+		Env.assert(false);
 		return super.removeChild(component);
-  }
+	}
 
 	/**
 		* The {@link recycleComponent} was loaded.
 		* Create and add children here.
 		*/
-	protected onRecycled(component: Component): void {};
+	protected onRecycled(component: Component): void { }; // eslint-disable-line @typescript-eslint/no-unused-vars
 
 	/** The {@link recycleComponent} is about to unload. */
-	protected onRecycling(): void {};
+	protected onRecycling(): void { };
 
 	protected get recycleComponent() {
 		return this.internalRecycleComponent!;
@@ -46,15 +46,12 @@ export abstract class RecycleComponent extends Component {
 
 	private create(): void {
 		this.internalRecycleComponent = new Component();
-
+		this.internalRecycleComponent.load();
-		if (this.internalRecycleComponent) {
+		this.onRecycled(this.internalRecycleComponent);
-			this.internalRecycleComponent.load();
-			this.onRecycled(this.internalRecycleComponent);
-		}
 	}
 
 	private dispose(): void {
-		if (this.internalRecycleComponent) {
+		if (this.internalRecycleComponent !== null) {
 			this.onRecycling();
 			// Clears its internal list of children and deregisters all its resources. The component is disposed and should no longer be used.
 			this.internalRecycleComponent.unload();

src/utils/obs/ViewAssistant.ts

@@ -1,11 +1,15 @@
-import { Env } from "env";
+import { Env } from "#/env";
+import { El } from "#/utils/dom/dom";
+import { UnexpectedUndefinedError } from "#/utils/errors";
+import { CssClass, HtmlAttribute } from "#/utils/obs/constants";
+import { Arr } from "#/utils/ts";
 import { ItemView } from "obsidian";
-import { UnexpectedUndefinedError } from "utils/errors";
-import { CssClass } from "utils/obs/constants";
-import { Arr } from "utils/ts";
 
+/** Knows about the Obsidian specifc DOM structure. */
 export class ViewAssistant {
 
+	/** `<div class="workspace-leaf-content …>` */
+	private workspaceLeafContentEl: HTMLElement | undefined;
 	private markdownViewRootEl: HTMLDivElement | undefined;
 	private previewView: HTMLDivElement | undefined;
 	private previewSizerEl: HTMLDivElement | undefined;
@@ -13,6 +17,9 @@ export class ViewAssistant {
 	public init(view: ItemView) {
 		this.deinit();
 
+		this.workspaceLeafContentEl = view.containerEl;
+		El.setAttribute(this.workspaceLeafContentEl, HtmlAttribute.Data.MODE, CssClass.Workspace.Data.PREVIEW_MODE);
+
 		this.markdownViewRootEl = view.contentEl.createDiv({ cls: CssClass.MarkdownView.READING }, (readerViewEl) => {
 			this.previewView = readerViewEl.createDiv({ cls: Arr.toMutable(CssClass.MarkdownView.PREVIEW) }, (previewViewEl) => {
 				this.previewSizerEl = previewViewEl.createDiv({ cls: Arr.toMutable(CssClass.MarkdownView.SIZER) }, (el) => {
@@ -23,8 +30,18 @@ export class ViewAssistant {
 		});
 	}
 
+	public get isInitialized(): boolean {
+		return this.markdownViewRootEl !== undefined;
+	}
+
 	/** Undos what {@link init} did. */
 	public deinit() {
+
+		if (this.workspaceLeafContentEl !== undefined) {
+			El.removeAttribute(this.workspaceLeafContentEl, HtmlAttribute.Data.MODE);
+			this.workspaceLeafContentEl = undefined;
+		}
+
 		if (this.markdownViewRootEl) {
 			this.markdownViewRootEl.empty();
 			this.markdownViewRootEl = undefined;
@@ -33,7 +50,7 @@ export class ViewAssistant {
 	}
 
 	public empty() {
-		if (this.previewSizerEl) {
+		if (this.previewSizerEl !== undefined) {
 			const children = this.previewSizerEl.children;
 			for (let i = children.length - 1; i >= 2; i--) {
 				const child = children[i];
@@ -44,33 +61,37 @@ export class ViewAssistant {
 		}
 	}
 
+	/** @throws `Error` if {@link init} has not been called. */
+	public get workspaceLeafEl() {
+		this.throwIfNotInitialized(this.workspaceLeafContentEl);
+		return this.workspaceLeafContentEl;
+	}
+
 	/** @throws `Error` if {@link init} has not been called. */
 	public get containerEl() {
-		if (this.markdownViewRootEl === undefined)
+		this.throwIfNotInitialized(this.markdownViewRootEl);
-			throw new Error("Not initialized.");
 		return this.markdownViewRootEl;
 	}
 
 	/** @throws `Error` if {@link init} has not been called. */
 	public get contentEl() {
-		if (this.previewSizerEl === undefined)
+		this.throwIfNotInitialized(this.previewSizerEl);
-			throw new Error("Not initialized.");
 		return this.previewSizerEl;
 	}
 
+	/** @throws `Error` if {@link init} has not been called. */
 	public get scrollContainer() {
+		this.throwIfNotInitialized(this.previewView);
 		return this.previewView;
 	}
 
 	public adjustAvailableVerticalScrolling() {
-		if (!this.scrollContainer || !this.previewSizerEl)
-			return;
 
 		const containerHeight = this.scrollContainer.clientHeight;
 		const paddingBottom = Math.floor(containerHeight * 0.5);
 		const minHeight = Math.floor(containerHeight * 0.53);
 
-		this.previewSizerEl.setCssStyles({
+		this.contentEl.setCssStyles({
 			"paddingBottom": `${paddingBottom}px`,
 			"minHeight": `${minHeight}px`,
 		});
@@ -78,4 +99,8 @@ export class ViewAssistant {
 		Env.log.view(`ViewAssistant:adjustAvailableVerticalScrolling: \`padding-bottom\`: "${paddingBottom}px", \`min-height\`: "${minHeight}px"`);
 	}
 
+	private throwIfNotInitialized<T extends HTMLElement | undefined>(el: T): asserts el is Exclude<T, undefined> {
+		if (el === undefined)
+			throw new Error("Not initialized.");
+	}
 }

src/utils/obs/constants.ts

@@ -1,9 +1,50 @@
+export const HtmlAttribute = {
+	Data: {
+		MODE: "data-mode"
+	}
+} as const;
+
 export const CssClass = {
 
 	wrapperClassForEl: <K extends keyof HTMLElementTagNameMap>(tag: K) => {
 		return "el-" + tag;
 	},
 
+	Body: {
+
+		Setting: {
+			/**
+				* Added when "Full screen" is enabled in settings.
+				* "Automatically hide interface elements while reading."
+				*
+				*/
+			AUTO_FULL_SCREEN: "auto-full-screen",
+
+			/**
+				* Added when "Floating navigation" is enabled in settings.
+				* "Navigation buttons float over the content instead of being anchored."
+				*/
+			IS_FLOATING_NAV: "is-floating-nav",
+		},
+
+		Platform: {
+			IS_PHONE: "is-phone",
+		},
+
+		Interface: {
+			/** Added when the navigation such as the header view is hidden (or about to be hidden once transitioned). */
+			IS_HIDDEN_NAV: "is-hidden-nav",
+			IS_SHOW_INDENT_GUIDE: "show-indentation-guide"
+		}
+	},
+
+	Workspace: {
+		LEAF_CONTENT_MODIFIER: "workspace-leaf-content",
+		Data: {
+			PREVIEW_MODE: "preview"
+		}
+	},
+
 	MarkdownView: {
 		READING: "markdown-reading-view",
 

src/utils/obs/dom.ts

@@ -84,17 +84,3 @@ export function createElWrapperHtml<K extends keyof HTMLElementTagNameMap>(tag:
 	else
 		return `<div class="${CssClass.wrapperClassForEl(tag)}">${html}</div>`;
 }
-
-/**
-	* Use `element.win` and `element.doc` to get the window/document that your Dom element is located in.
-	*
-	* `activeWindow`/`Document` refers to the current focused window which might not be the same one your element is in.
-	*/
-export function getDoc(el: HTMLElement) {
-	return el.doc;
-}
-
-/** @see {@link getDoc} */
-export function getWin(el: HTMLElement) {
-	return el.win;
-}

src/utils/obs/internal.ts

@@ -1,5 +1,6 @@
-import { Env } from "env";
+import { Env } from "#/env";
-import { App, KeymapEventListener, Scope } from "obsidian";
+import { Bln } from "#/utils/ts";
+import { App, KeymapEventListener, Scope, Vault } from "obsidian";
 
 export const InternalApi = {
 
@@ -41,4 +42,28 @@ export const InternalApi = {
 		}
 	},
 
+	getConfig: (vault: Vault, key: "autoFullScreen" | "floatingNavigation" | "showInlineTitle" | "showIndentGuide" | "rightToLeft") => {
+		try {
+			// @ts-expect-error
+			const value = vault.getConfig(key);
+			return Bln.isTrue(value);
+		}
+		catch (e) {
+			Env.log.e("Failed to get config.", e, key);
+			return false;
+		}
+	},
+
+	hideNav: (app: App, hide: boolean) => {
+		try {
+			if (hide)
+				(app as any).mobileNavbar?.hideNavigation(); // eslint-disable-line @typescript-eslint/no-explicit-any
+			else
+				(app as any).mobileNavbar?.restoreNavigation(); // eslint-disable-line @typescript-eslint/no-explicit-any
+		}
+		catch (e) {
+			Env.log.e("Failed to hide navigation.", e);
+		}
+	}
+
 } as const;

src/utils/ts.ts

@@ -2,11 +2,20 @@ import { Env } from "env";
 import { UnsignedInteger } from "types";
 import { TimeoutError } from "utils/errors";
 
+/** Strips index signatures to ensure only hard-coded properties are allowed in the union. */
+export type StrictKeys<T> = keyof {
+	[K in keyof T as string extends K ? never : number extends K ? never : K]: unknown;
+};
+
+/** Extract only the keys present in T1 that are not in T2 using {@link StrictKeys}. */
+export type LocalStrictKeys<T1, T2> = Exclude<StrictKeys<T1>, StrictKeys<T2>>;
+
 export const Arr = {
 	firstOrNull: <T>(a: Array<T>): T | null => a.first() ?? null,
 	nonEmpty: <T>(v: T[] | unknown): v is Array<T> => Array.isArray(v) && v.length > 0,
 	toMutable: <T>(a: readonly T[]): T[] => [...a],
-} as const;
+	clear: <T>(a: T[]): void => { a.length = 0; },
+};
 
 export const Async = {
 	/**
@@ -40,22 +49,34 @@ export const Async = {
 			timeoutPromise
 		]);
 	}
-}
+};
+
+export type BoolStr = "true" | "false";
+
+export const Bln = {
+	is: (value: unknown): value is boolean => typeof value === "boolean",
+	isTrue: (value: unknown): value is boolean => typeof value === "boolean" && value === true,
+	TRUE_STR: "true" as BoolStr,
+	isTrueStr: (value: unknown): boolean => typeof value === "string" && value === Bln.TRUE_STR,
+};
+
 
 export const Err = {
 	toError: (e: unknown): Error => e instanceof Error ? e : new Error(String(e)),
-} as const;
+};
 
 export const KeyValue = {
 	isNotEmpty: <K, V>(v: Map<K, V> | undefined): v is Map<K, V> => v !== undefined && v.size > 0,
-} as const;
+};
 
 export const Num = {
 
 	is: (value: unknown): value is number => {
-		return typeof value === "number";
+		return typeof value === "number" && !Number.isNaN(value);
 	},
 
+	isNaN: (value: unknown) => Number.isNaN(value),
+
 	UInt: {
 		assert: (n: number) => Env.assert(isUnsignedInteger(n)),
 		create: (n: number): UnsignedInteger => {
@@ -66,7 +87,11 @@ export const Num = {
 		is: isUnsignedInteger,
 	} as const,
 
-} as const;
+};
+
+export const Null = {
+	is: (value: unknown): value is null => value === null, // typeof value === "object" && !Str.is(value) && !Num.is(value) && !Bln.is(value)
+};
 
 export const Obj = {
 	/**
@@ -76,18 +101,85 @@ export const Obj = {
 		* @returns `true` if `typeof` for {@link value} returns `"object"` and {@link value} is not `null`.
 		*/
 	is: (value: unknown): value is object => {
-		return typeof value === "object" && value !== null; // `null` is an object
+		return typeof value === "object" && value !== null; // In JavaScript runtime, `null` is an object. In TypeScript, with `strictNullChecks`, it is not.
 	},
-}
+
+	/**
+		* Trims all string values of top-level properties of {@link obj} in place (non-recursive).
+		*
+		* @param obj The object whose string values to trim. Non-string values are ignored.
+		*/
+	trimValues: (obj: Record<string, unknown>): void => {
+		for (const key of Object.keys(obj)) {
+			const value = obj[key];
+			if (Str.is(value))
+				obj[key] = value.trim();
+		}
+	},
+
+	/**
+		* @param obj
+		* @param key
+		* @param callbacks Optional validation functions. Each receives the property value, the object itself, and the key.
+		* @returns `true` if {@link obj} is an object and the {@link key} exists and all {@link callbacks} pass.
+		*/
+	hasKey: <T extends Record<string, unknown>, K extends StrictKeys<T>>(
+		obj: Record<string, unknown>,
+		key: K,
+		...callbacks: Array<(value: T[K], obj: Record<string, unknown>, key: K) => boolean>
+	): boolean => {
+
+		if (!Obj.is(obj) || !Object.hasOwn(obj, key as PropertyKey))
+			return false;
+
+		return callbacks.every((cb) => cb(obj[key] as T[K], obj, key));
+	},
+
+	getKey: <T extends Record<string, unknown>, K extends StrictKeys<T>>(
+		obj: Record<string, unknown>,
+		key: K
+	): T[K] => {
+		return obj[key] as T[K];
+	},
+
+	setKey: <T extends Record<string, unknown>, K extends StrictKeys<T>>(
+		obj: Record<string, unknown>,
+		key: K,
+		value: T[K]
+	): void => {
+		obj[key] = value;
+	},
+};
 
 export const Str = {
 	EMPTY: "",
 	SPACE: " ",
 	NON_BREAKING_SPACE: " ",
+	LF: "\n",
+	TAB: "\t",
 
+	/**
+		* Checks whether `value` is a string.
+		*
+		* @param value The value to check.
+		* @returns `true` if `value` is a string, otherwise `false`.
+		*/
 	is: (value: unknown): value is string => typeof value === "string",
+
+	/**
+		* Checks whether `value` is a non-empty string.
+		*
+		* @param value The value to check.
+		* @returns `true` if `value` is a string with at least one character, otherwise `false`.
+		*/
 	isNonEmpty: (value: unknown): value is string => typeof value === "string" && value !== "",
 
+	/**
+		* Returns `value` if it is a non-empty string, otherwise `undefined`.
+		*
+		* @param value The value to check.
+		* @returns The original string if non-empty, or `undefined`.
+		*/
 	nonEmpty: (value: unknown): string | undefined => typeof value === "string" && value !== "" ? value : undefined,
 
 	/**
@@ -102,8 +194,50 @@ export const Str = {
 	toIsoStringOrNull: (date: Date | undefined) => {
 		return date !== undefined ? date.toISOString() : null
 	},
-} as const;
+};
 
 function isUnsignedInteger(value: unknown): value is UnsignedInteger {
 	return Num.is(value) && Number.isInteger(value) && value >= 0;
 }
+
+/**
+	* A second union member to suppress ESLint's `no-unnecessary-condition` rule from firing. This occurs when TypeScript narrows a union to a single literal (i.e. the union has only one real value), making comparisons appear always true.
+	*
+	* @example
+	* // Without UNARY_UNION_SUPPRESS, ESLint warns: "comparison is always true, since 'value' === 'value'"
+	* type MyType = "value";
+	*
+	* // With UNARY_UNION_SUPPRESS, the union has two values and ESLint is satisfied:
+	* type MyType = "value" | typeof UNARY_UNION_SUPPRESS;
+	*
+	* // In a switch, add a case for UNARY_UNION_SUPPRESS to satisfy exhaustiveness checking.
+	* // The default case handles truly unexpected values:
+	* switch (myValue) {
+	*	  case UNARY_UNION_SUPPRESS:
+	*		  break;
+	*	  case "value": {
+	*		  // handle value
+	*		  break;
+	*	  }
+	*   // Also possible to cover unexpected value if needed, e.g., if value comes from user.
+	*	  //default:
+	*	  //  throw new Error(`Unexpected value: ${myValue}`);
+	* }
+	*
+	* // Once a second real value is added to the union, UNARY_UNION_SUPPRESS is no longer needed and can be removed:
+	* type MyType = "value" | "anotherValue";
+	*
+	* switch (myValue) {
+	*	  case "value": {
+	*		  // handle value
+	*		  break;
+	*	  }
+	*	  case "anotherValue": {
+	*		  // handle anotherValue
+	*		  break;
+	*	  }
+	*	  //default:
+	*	  //  throw new Error(`Unexpected value: ${myValue}`);
+	* }
+	*/
+export const UNARY_UNION_SUPPRESS = "suppress" as const;

src/views/BaseView.ts

@@ -1,19 +1,23 @@
-import { DataStore, DataStoreRoot } from "data/DataStore";
+import { CssClass } from "#/constants";
-import { Env } from "env";
+import { DataStore, DataStoreRoot } from "#/data/DataStore";
+import { Env } from "#/env";
+import { ContentRenderer, createRenderConfig } from "#/renderings/content/ContentRenderer";
+import { PluginSettings, SettingsChanged, SettingsManager } from "#/Settings";
+import { Icon } from "#/ui/constants";
+import { Doc, El } from "#/utils/dom/dom";
+import { ElementCreator } from "#/utils/ElementCreator";
+import { InteractionAssistant } from "#/utils/obs/InteractionAssistant";
+import { ViewAssistant } from "#/utils/obs/ViewAssistant";
+import { Bln } from "#/utils/ts";
 import { IconName, ItemView, ViewStateResult, WorkspaceLeaf } from "obsidian";
-import { ContentRenderer, createRenderConfig } from "renderings/content/ContentRenderer";
-import { PluginSettings, SettingsChanged, SettingsManager } from "Settings";
-import { Icon } from "ui/constants";
-import { ElementCreator } from "utils/ElementCreator";
-import { getDoc } from "utils/obs/dom";
-import { ViewAssistant } from "utils/obs/ViewAssistant";
-import { CssClass } from "views/constants";
 
 export type BaseViewOptionalParameters = {
 	data?: DataStore;
 };
 
 export interface BaseViewState {
+	/** {@link BaseView.prototype.setState} only forwards the state to subclasses once unless this is set. Therefore, set this to render based on a new state in an already opened view. Use {@linkcode BaseView.withDefaultViewState}. */
+	forceUpdate?: boolean;
 	[key: string]: unknown;
 }
 
@@ -21,10 +25,21 @@ export interface BaseViewEphemeralState {
 	[key: string]: unknown;
 }
 
+export interface BaseViewScrollToOptions extends ScrollToOptions { // eslint-disable-line @typescript-eslint/no-empty-object-type
+}
+
 export abstract class BaseView<State extends BaseViewState> extends ItemView {
 
+	protected static withDefaultViewState<T extends BaseViewState>(state: T): T {
+		return {
+			...state,
+			forceUpdate: true
+		};
+	}
+
 	protected readonly settingsManager: SettingsManager;
 	protected readonly contentRenderer: ContentRenderer;
+	protected readonly interactionAssistant: InteractionAssistant;
 
 	private readonly options?: BaseViewOptionalParameters;
 	private readonly viewAssistant: ViewAssistant;
@@ -38,6 +53,7 @@ export abstract class BaseView<State extends BaseViewState> extends ItemView {
 		this.options = options;
 
 		this.viewAssistant = new ViewAssistant();
+		this.interactionAssistant = new InteractionAssistant(this.app, this, this.viewAssistant);
 		this.contentRenderer = new ContentRenderer(this.app, createRenderConfig(settingsManager.settings));
 		this.addChild(this.contentRenderer);
 	}
@@ -67,8 +83,10 @@ export abstract class BaseView<State extends BaseViewState> extends ItemView {
 		}
 
 		this.contentEl.empty();
-		this.containerEl.addClass(CssClass.WORKSPACE_LEAF_CONTENT_MODIFIER);
 		this.viewAssistant.init(this);
+		this.interactionAssistant.init(Doc.get(this.contentEl));
+
+		El.Cls.add(this.viewAssistant.workspaceLeafEl, CssClass.View.WORKSPACE_LEAF_CONTENT_MODIFIER);
 	}
 
 	protected override async onClose(): Promise<void> {
@@ -82,8 +100,10 @@ export abstract class BaseView<State extends BaseViewState> extends ItemView {
 
 		this.contentRenderer.unload(); // Will also be unloaded when this view unloads.
 		this.domFacade = null;
+
+		El.Cls.remove(this.viewAssistant.workspaceLeafEl, CssClass.View.WORKSPACE_LEAF_CONTENT_MODIFIER);
+		this.interactionAssistant.deinit();
 		this.viewAssistant.deinit();
-		this.containerEl.removeClass(CssClass.WORKSPACE_LEAF_CONTENT_MODIFIER);
 	}
 
 	public override onResize(): void {
@@ -98,13 +118,21 @@ export abstract class BaseView<State extends BaseViewState> extends ItemView {
 		Env.log.d("BaseView:setState:", this.didSetState, state);
 		await super.setState(state, result);
 
-		if (!this.didSetState) {
+		const setState = state as State | null | undefined;
-			this.onSetState(state as State, result);
+		Env.assert(setState !== undefined && setState !== null);
-			this.didSetState = true;
+		if (setState === undefined || setState === null)
+			return;
 
-			//this.contentRenderer.recycle();
+		const proceed = async () => {
-			Env.log.view("BaseView:setState: refreshing view because state was set");
+			this.onSetState(setState, result);
 			await this.render();
+		};
+
+		if (!this.didSetState) {
+			this.didSetState = true;
+			await proceed();
+		} else if (Bln.isTrue(setState.forceUpdate)) {
+			await proceed();
 		}
 	}
 	/** Subclasses should store and manage their own {@link BaseViewState}. {@link onSetState} is only called once per instantiation of this class. */
@@ -182,22 +210,24 @@ export abstract class BaseView<State extends BaseViewState> extends ItemView {
 	protected abstract onSetState(state: State, result: ViewStateResult): void;
 	/** Supply the state to the system. */
 	protected abstract onGetState(): State;
-	protected onSetEphemeralState(state: unknown): void { };
+	protected onSetEphemeralState(state: unknown): void { }; // eslint-disable-line @typescript-eslint/no-unused-vars
 	protected onGetEphemeralState(): Record<string, unknown> { return {}; };
 	protected abstract onRender(): Promise<void>;
 
-	protected onDataChanged(data: DataStoreRoot, out: { skipRender: boolean }): void { };
+	protected onDataChanged(data: DataStoreRoot, out: { skipRender: boolean }): void { }; // eslint-disable-line @typescript-eslint/no-unused-vars
-	protected onSettingsChanged(settings: PluginSettings, isExternal: boolean, out: { skipRender: boolean }): void { };
+	protected onSettingsChanged(settings: PluginSettings, isExternal: boolean, out: { skipRender: boolean }): void { }; // eslint-disable-line @typescript-eslint/no-unused-vars
 
 	protected get scrollPosition(): { top: number, left: number } {
-		return this.viewAssistant.scrollContainer
+		return {
-			? { top: this.viewAssistant.scrollContainer.scrollTop, left: this.viewAssistant.scrollContainer.scrollLeft }
+			top: this.viewAssistant.scrollContainer.scrollTop, left: this.viewAssistant.scrollContainer.scrollLeft
-			: { top: 0, left: 0 };
+		};
 	}
 
-	protected setScrollPosition(options: ScrollToOptions) {
+	/** The call is asynchronous, i.e., the scroll position is not updated immediately. */
+	protected setScrollPosition(options: BaseViewScrollToOptions) {
 		Env.log.d("BaseView:setScrollPosition", options);
-		this.viewAssistant.scrollContainer?.scrollTo(options)
+		this.interactionAssistant.nextScrollIsProgrammatic();
+		this.viewAssistant.scrollContainer.scrollTo(options)
 	}
 
 	protected saveState() {
@@ -212,7 +242,7 @@ export abstract class BaseView<State extends BaseViewState> extends ItemView {
 			this.domFacade = {
 				contentEl: contentEl,
 				create: new ElementCreator(contentEl),
-				doc: getDoc(contentEl),
+				doc: Doc.get(contentEl),
 			}
 		}
 		return this.domFacade;

src/views/DecksView.ts

@@ -8,6 +8,10 @@ export class DecksView extends BaseView<BaseViewState> {
 
 	public static readonly TYPE = "come-through-view-decks";
 
+	public static createViewState(): BaseViewState {
+		return BaseView.withDefaultViewState({});
+	}
+
 	private readonly data: DataStore;
 
 	constructor(leaf: WorkspaceLeaf, settingsManager: SettingsManager, data: DataStore) {
@@ -29,7 +33,7 @@ export class DecksView extends BaseView<BaseViewState> {
 		return "Decks";
 	}
 
-	protected override onSetState(state: BaseViewState, result: ViewStateResult): void {
+	protected override onSetState(_state: BaseViewState, _result: ViewStateResult): void {
 	}
 
 	protected override onGetState(): BaseViewState {
@@ -78,7 +82,7 @@ export class DecksView extends BaseView<BaseViewState> {
 						el.createEl("button", { text: "Add" }, (button) => {
 							setIcon(button, "plus");
 							setTooltip(button, "Add new deck");
-							this.contentRenderer.registerDomEvent(button, "click", () => new DeckModal(this.app, this.data, () => { }).open());
+							this.contentRenderer.registerDomEvent(button, "click", () => DeckModal.add(this.app, this.data));
 						});
 					});
 				});
@@ -105,7 +109,7 @@ export class DecksView extends BaseView<BaseViewState> {
 									menu.addItem((item) => {
 										item.setTitle("Edit");
 										item.setIcon("pen");
-										item.onClick(() => new DeckModal(this.app, this.data, () => { }, deck.id).open());
+										item.onClick(() => DeckModal.edit(this.app, this.data, deck.id));
 									});
 
 									menu.addItem((item) => {

src/views/DefinedContentView.ts

@@ -14,9 +14,9 @@ export class DefinedContentView extends BaseView<DefinedContentViewState> {
 
 	public static readonly TYPE = "come-through-view-defined-content";
 	public static createViewState(file: TFile): DefinedContentViewState {
-		return {
+		return BaseView.withDefaultViewState({
 			filePath: file.path,
-		};
+		} satisfies DefinedContentViewState);
 	}
 
 	/**
@@ -25,9 +25,6 @@ export class DefinedContentView extends BaseView<DefinedContentViewState> {
 		*/
 	private file: TFile | null | undefined;
 
-	/** Keeps track of which details elements have been dynamically created on expand. */
-	private hasRendered: WeakMap<HTMLDetailsElement, boolean>;
-
 	/**
 		* @param data Used to receive data changed notifications.
 		*/
@@ -55,12 +52,14 @@ export class DefinedContentView extends BaseView<DefinedContentViewState> {
 		// Note that the data change callback will also be called on file rename.
 		// The "rename" event will be called first.
 		// The difference is that when there's a rename event, we want to update the display text.
-		this.registerEvent(this.app.vault.on("rename", this.onFileRename.bind(this)));
+		this.registerEvent(this.app.vault.on("rename", (file, oldPath) => {
+			if (file instanceof TFile)
+				this.onFileRename(file, oldPath);
+		}));
 	}
 
 	public override onunload(): void {
 		super.onunload();
-		this.hasRendered = new WeakMap<HTMLDetailsElement, boolean>();
 	}
 
 	public override onPaneMenu(menu: Menu, source: 'more-options' | 'tab-header' | string): void {
@@ -76,7 +75,7 @@ export class DefinedContentView extends BaseView<DefinedContentViewState> {
 		});
 	}
 
-	protected override onSetState(state: DefinedContentViewState, result: ViewStateResult): void {
+	protected override onSetState(state: DefinedContentViewState, _result: ViewStateResult): void {
 		this.file = state.filePath ? this.app.vault.getFileByPath(state.filePath) : undefined;
 		this.contentRenderer.file = this.file;
 	}
@@ -119,7 +118,9 @@ export class DefinedContentView extends BaseView<DefinedContentViewState> {
 
 		// <summary> is styled as a <h2>, this will normalize its children to start at <h3>.
 		this.contentRenderer.setCustomProcessors([new HeadingProcessor(3)]);
-		this.hasRendered = new WeakMap<HTMLDetailsElement, boolean>();
+
+		// Keeps track of which details elements have been dynamically created on expand.
+		const hasRendered = new WeakMap<HTMLDetailsElement, boolean>();
 
 		this.dom.create.el("h1", { text: t.views.declarations.title(this.file) });
 		const infoPara = this.dom.create.paraWrapper();
@@ -137,19 +138,19 @@ export class DefinedContentView extends BaseView<DefinedContentViewState> {
 
 			if (parsedUnit.complete !== null) {
 				const completeUnit = parsedUnit.complete;
-				this.createDefinedContentBlockSection(`${completeUnit.frontID.cardID}: Front`, completeUnit.frontMarkdown);
+				this.createDefinedContentBlockSection(hasRendered, `${completeUnit.frontID.cardID}: Front`, completeUnit.frontMarkdown);
-				this.createDefinedContentBlockSection(`${completeUnit.backID.cardID}: Back`, completeUnit.backMarkdown);
+				this.createDefinedContentBlockSection(hasRendered, `${completeUnit.backID.cardID}: Back`, completeUnit.backMarkdown);
 				numberOfContentDefinitions += 2;
 			}
 			else if (parsedUnit.incomplete !== null) {
 				const incompleteUnit = parsedUnit.incomplete;
 
 				if (incompleteUnit.frontID) {
-					this.createDefinedContentBlockSection(`${incompleteUnit.frontID.cardID}: Front (incomplete)`, incompleteUnit.frontMarkdown);
+					this.createDefinedContentBlockSection(hasRendered, `${incompleteUnit.frontID.cardID}: Front (incomplete)`, incompleteUnit.frontMarkdown);
 					numberOfIncompleteContentDefinitionsInFile += 1;
 				}
 				if (incompleteUnit.backID) {
-					this.createDefinedContentBlockSection(`${incompleteUnit.backID.cardID}: Back (incomplete)`, incompleteUnit.backMarkdown);
+					this.createDefinedContentBlockSection(hasRendered, `${incompleteUnit.backID.cardID}: Back (incomplete)`, incompleteUnit.backMarkdown);
 					numberOfIncompleteContentDefinitionsInFile += 1;
 				}
 			}
@@ -163,13 +164,13 @@ export class DefinedContentView extends BaseView<DefinedContentViewState> {
 		await this.contentRenderer.render(markdownText, infoPara);
 	}
 
-	private createDefinedContentBlockSection(summary: string, content?: string) {
+	private createDefinedContentBlockSection(hasRendered: WeakMap<HTMLDetailsElement, boolean>, summary: string, content?: string) {
 		this.dom.create.el("details", undefined, (detailsEl) => {
 			detailsEl.createEl("summary", { text: summary });
 			const contentDiv = detailsEl.createDiv();
 			this.contentRenderer.registerDomEvent(detailsEl, "toggle", async () => {
-				if (detailsEl.open && !this.hasRendered.has(detailsEl)) {
+				if (detailsEl.open && !hasRendered.has(detailsEl)) {
-					this.hasRendered.set(detailsEl, true);
+					hasRendered.set(detailsEl, true);
 					if (content)
 						await this.contentRenderer.render(content, contentDiv);
 				}

src/views/constants.ts

@@ -1,3 +0,0 @@
-export const CssClass = {
-	WORKSPACE_LEAF_CONTENT_MODIFIER: "come-through-workspace-leaf-content"
-} as const;

src/views/review/ReviewView.ts

@@ -1,26 +1,32 @@
-import { ContentParser } from "ContentParser";
+import { ContentParser } from "#/ContentParser";
-import { DataStore, DeckIDDataTuple } from "data/DataStore";
+import { DataStore, DeckIDDataTuple } from "#/data/DataStore";
-import { DeckID } from "data/FullID";
+import { DeckID } from "#/data/FullID";
-import { Env } from "env";
+import { Env } from "#/env";
-import t from "Localization";
+import t from "#/Localization";
-import { ReviewItemInfoModal } from "modals/ReviewItemInfoModal";
+import { ReviewItemInfoModal } from "#/modals/ReviewItemInfoModal";
+import { HeadingProcessor } from "#/renderings/content/HeadingProcessor";
+import { ReviewItemInfo } from "#/scheduling/ReviewItemInfo";
+import { Scheduler } from "#/scheduling/Scheduler";
+import { NextReviewItemOptions, Rating, ReviewSortOrder } from "#/scheduling/types";
+import { SettingsManager } from "#/Settings";
+import { OmitIndexSignature, UnsignedInteger } from "#/types";
+import { Icon } from "#/ui/constants";
+import { UIAssistant } from "#/ui/UIAssistant";
+import { UnexpectedUndefinedError } from "#/utils/errors";
+import { FileParserError } from "#/utils/obs/FileParser";
+import { InternalApi } from "#/utils/obs/internal";
+import { Bln, Num, Obj, Str } from "#/utils/ts";
+import { BaseView, BaseViewEphemeralState, BaseViewState } from "#/views/BaseView";
+import { ContentUnit } from "#/views/review/ContentUnit";
+import { createMetadataEl, createRatingButtons } from "#/views/review/elements";
+import { ReviewState } from "#/views/review/types";
 import { IconName, Keymap, KeymapEventListener, Menu, PaneType, Scope, setIcon, setTooltip, TFile, ViewStateResult, WorkspaceLeaf } from "obsidian";
-import { HeadingProcessor } from "renderings/content/HeadingProcessor";
+
-import { ReviewItemInfo } from "scheduling/ReviewItemInfo";
+declare global {
-import { Scheduler } from "scheduling/Scheduler";
+	interface DOMStringMap {
-import { Rating } from "scheduling/types";
+		didAdjustButtons?: import("#/utils/ts").BoolStr;
-import { NextReviewItemOptions, ReviewSortOrder } from "scheduling/types";
+	}
-import { SettingsManager } from "Settings";
+}
-import { OmitIndexSignature, UnsignedInteger } from "types";
-import { Icon } from "ui/constants";
-import { UIAssistant } from "ui/UIAssistant";
-import { FileParserError } from "utils/obs/FileParser";
-import { InternalApi } from "utils/obs/internal";
-import { Num, Obj, Str } from "utils/ts";
-import { BaseView, BaseViewEphemeralState, BaseViewState } from "views/BaseView";
-import { ContentUnit } from "views/review/ContentUnit";
-import { createMetadataEl, createRatingButtons } from "views/review/elements";
-import { ReviewState } from "views/review/types";
 
 interface ReviewViewState extends BaseViewState {
 	deckID: DeckID | null;
@@ -51,12 +57,12 @@ export class ReviewView extends BaseView<ReviewViewState> {
 	public static readonly TYPE = "come-through-view-review";
 	public static createViewState(deckID: DeckID | null): ReviewViewState {
 		Env.log.d("ReviewView:createViewState: collection ID:", deckID);
-		return {
+		return BaseView.withDefaultViewState({
 			...DEFAULT_STATE,
 			...{
 				deckID: deckID,
 			},
-		} satisfies ReviewViewState;
+		} satisfies ReviewViewState);
 	}
 
 	private readonly data: DataStore;
@@ -177,14 +183,6 @@ export class ReviewView extends BaseView<ReviewViewState> {
 		return this.deck ? `Review: ${this.deck.data.n}` : "Review";
 	}
 
-	public override onload(): void {
-		Env.log.d("ReviewView:onload");
-		super.onload();
-
-		if (Env.isMobile)
-			this.registerDomEvent(this.contentEl, "dblclick", () => { this.displayNextContentItem(); });
-	}
-
 	public override onPaneMenu(menu: Menu, source: 'more-options' | 'tab-header' | string): void {
 		Env.log.d("ReviewView:onPaneMenu");
 		super.onPaneMenu(menu, source);
@@ -241,17 +239,40 @@ export class ReviewView extends BaseView<ReviewViewState> {
 		Env.log.d("ReviewView:onOpen");
 		await super.onOpen();
 
+		if (Env.isMobile)
+			this.interactionAssistant.registerDoubleClick(this.contentEl, () => this.displayNextContentItem());
+
 		const props = this.forwardBackwardButtonProps();
 		this.displayNextContentButton = this.addAction(props.icon, props.title, () => this.displayNextContentItem());
 	}
 
-	protected override onSetState(state: ReviewViewState, result: ViewStateResult): void {
+	protected override onSetState(state: ReviewViewState, _result: ViewStateResult): void {
 		Env.log.d("ReviewView:onSetState", state);
-		this.state = { ...DEFAULT_STATE, ...state };
+
-		this.deck = state.deckID ? {
+		const setState = () => {
-			id: state.deckID,
+			this.state = { ...DEFAULT_STATE, ...state };
-			data: this.data.getDeck(state.deckID, true)!
+			this.deck = state.deckID ? {
-		} : null;
+				id: state.deckID,
+				data: this.data.getDeck(state.deckID, true)!
+			} : null;
+		};
+
+		if (Bln.isTrue(state.forceUpdate)) {
+
+			// Makes sense to retain these "settings" when the same leaf is reused.
+			const retainedStateProps = DEFAULT_STATE;
+			retainedStateProps.sortOrder = this.state.sortOrder;
+			retainedStateProps.showMetadata = this.state.showMetadata;
+
+			setState();
+
+			this.state.sortOrder = retainedStateProps.sortOrder;
+			this.state.showMetadata = retainedStateProps.showMetadata;
+
+			this.removeAllPages(true);
+		} else {
+			setState();
+		}
 	}
 
 	protected override onGetState(): ReviewViewState {
@@ -498,8 +519,11 @@ export class ReviewView extends BaseView<ReviewViewState> {
 		this.refreshUI();
 	}
 
+	/**
+		* Gets the avalable content from the pager and inserts it into the DOM, replacing the current content.
+		*/
 	private displayPageAtIndex(index: UnsignedInteger): boolean {
-		Env.log.d("ReviewView:displayContentAtIndex:", index, "review", this.reviewState);
+		Env.log.d("ReviewView:displayPageAtIndex:", index, "review", this.reviewState);
 
 		Num.UInt.assert(index);
 		if (!Num.UInt.is(index))
@@ -526,7 +550,7 @@ export class ReviewView extends BaseView<ReviewViewState> {
 			this.dom.contentEl.appendChild(contentToDisplay);
 		}
 		else {
-			Env.assert(currentContent.parentElement); // Uncaught NotFoundError: Failed to execute 'replaceChild' on 'Node': The node to be replaced is not a child of this node.
+			Env.assert(currentContent.parentElement !== null); // Uncaught NotFoundError: Failed to execute 'replaceChild' on 'Node': The node to be replaced is not a child of this node.
 			this.dom.contentEl.replaceChild(contentToDisplay, currentContent);
 		}
 
@@ -539,6 +563,9 @@ export class ReviewView extends BaseView<ReviewViewState> {
 	/**
 		* Removes all cached pages/divs created from the last review unit.
 		*
+		* Sometimes you want to call render to build additional components, like the info view, without rebuilding the review content.
+		* Even if {@link BaseView.render} removes all content, the created pages are still retained/cached in the {@link pager} and inserted.
+		*
 		* @param includeEphemeralState Explicitly declare intent to reset ephemeral state
 		*/
 	private removeAllPages(includeEphemeralState: boolean) {
@@ -579,6 +606,7 @@ export class ReviewView extends BaseView<ReviewViewState> {
 		return this.pager.currentIndex === 1;
 	}
 
+	/** Adjusts the UI components (such as buttons, scrollbar) based on the current state. */
 	private refreshUI() {
 		Env.log.d("ReviewView:refreshUI");
 
@@ -626,7 +654,7 @@ export class ReviewView extends BaseView<ReviewViewState> {
 		if (!this.ratingButtonsContainer)
 			return;
 
-		if (this.ratingButtonsContainer.dataset.didAdjustButtons)
+		if (Bln.isTrueStr(this.ratingButtonsContainer.dataset.didAdjustButtons))
 			return;
 
 		// The container needs to be in the DOM otherwise widths may not be available.
@@ -638,14 +666,33 @@ export class ReviewView extends BaseView<ReviewViewState> {
 			return;
 
 		let maxWidth = 0;
+		let minContentWidth = Infinity;
+
 		ratingButtons.forEach((btn) => {
 			const width = btn.offsetWidth;
 			if (width > maxWidth)
 				maxWidth = width;
+
+			// Find the button whose content/text is of minimum width, this is used to widen the button if the radius is too large.
+			const firstChild = btn.firstElementChild;
+			if (firstChild instanceof HTMLElement && firstChild.offsetWidth < minContentWidth)
+				minContentWidth = firstChild.offsetWidth;
 		});
+
+		// The width of the wides button is now found.
+		// But before setting this width, check that the current radius (set by the Obsidian theme) is not so large that the button becomes a circle.
+		// If the radius is too large, adjust the width to avoid the circular appearance.
+		const firstBtn = ratingButtons[0];
+		if (firstBtn === undefined)
+			throw new UnexpectedUndefinedError();
+		const borderRadius = parseFloat(getComputedStyle(firstBtn).borderRadius);
+		const minDimension = Math.min(maxWidth, firstBtn.offsetHeight);
+		if (borderRadius >= minDimension / 2) // Radius is to large relative to the buttons dimensions. For example, a true circle results from a square button (equal width and height) with a radius of half that size.
+			maxWidth = borderRadius * 2 + (minContentWidth === Infinity ? 2 : minContentWidth) * 0.5; //"borderRadius * 2" is the width that makes it a circle, then whatever is added will make up the horizontal border.
+
 		ratingButtons.forEach(btn => btn.setCssProps({ "width": maxWidth + "px" }));
 
-		this.ratingButtonsContainer.dataset.didAdjustButtons = "yes";
+		this.ratingButtonsContainer.dataset.didAdjustButtons = "true";
 	}
 
 	/**

src/views/review/elements.ts

@@ -9,7 +9,7 @@ import { ElementCreator } from "utils/ElementCreator";
 import { KeyValue } from "utils/ts";
 import { ReviewState } from "views/review/types";
 
-export function createRatingButtons(nextItemsWithInfo: { item: NextItem, info: ReviewItemInfo }[], reviewState: ReviewState, sortOrder: ReviewSortOrder, cb: (button: HTMLButtonElement, rating: Rating) => void) {
+export function createRatingButtons(nextItemsWithInfo: { item: NextItem, info: ReviewItemInfo }[], reviewState: ReviewState, _sortOrder: ReviewSortOrder, cb: (button: HTMLButtonElement, rating: Rating) => void) {
 	Env.log.d("createRatingButtons");
 
 	const ratingButtonsContainer = createDiv({ cls: "rating-buttons" });
@@ -155,7 +155,7 @@ export function createMetadataEl(
 			}
 
 			row.add((col) => {
-				col.add({ text: "Last review" })
+				col.add({ text: "Last reviewed" })
 				const date = info.lastReview;
 				col.add({
 					text: date !== null ? DateTime.toString(date) : "This is the first review.",

styles/reviewView.css

@@ -16,6 +16,11 @@ div.come-through-workspace-leaf-content[data-type='come-through-view-review'] .r
 	width: auto;
 }
 
+/* Phone and tablet-specific line-height */
+.is-mobile div.come-through-workspace-leaf-content[data-type='come-through-view-review'] .rating-buttons > div > button {
+    line-height: 1.8;
+}
+
 /* Counter this selector: body.is-phone:not(.is-android:not(.material-off)) button:not(.clickable-icon) */
 div.come-through-workspace-leaf-content[data-type='come-through-view-review'] .view-content .rating-buttons > div > button {
 	justify-content: center;

styles/view.css

@@ -14,3 +14,17 @@ div.come-through-workspace-leaf-content .markdown-reading-view {
 div.come-through-workspace-leaf-content :lang(th) {
   font-size: 1.25rem;
 }
+
+/* Apr 25, 2026: Obsidian zeroes --view-top-spacing for markdown views via:
+ *
+ *   .workspace-leaf-content[data-type="markdown"] {
+ *     --view-top-spacing: 0;
+ *   }
+ *
+ * Custom views have a different data-type and do not get this automatically.
+ * Without it, double top spacing occurs when "Full screen" or "Floating
+ * navigation" is enabled (Appearance, mobile v1.11.6+).
+ */
+div.come-through-workspace-leaf-content {
+  --view-top-spacing: 0;
+}

tsconfig.json

@@ -1,22 +1,38 @@
 {
 	"compilerOptions": {
-		"baseUrl": "./src",
+		// Enable to check TS7 compatibility.
+		"stableTypeOrdering": false,
+
+		"rootDir": "./src",
+		"paths": {
+			"*": ["./src/*"],
+			"#/*": ["./src/*"]
+		},
+
 		"inlineSourceMap": true,
 		"inlineSources": true,
-		"module": "ESNext",
+
 		"target": "ES2022",
-		"allowJs": true,
-		"noImplicitAny": true,
-		"moduleResolution": "node",
-		"importHelpers": true,
-		"isolatedModules": true,
-		//"strict": true,
-		"strictNullChecks": true,
-		"noUncheckedIndexedAccess": true,
 		"lib": [
 			"DOM",
 			"ES2022"
-		]
+		],
+		"types": ["node"],
+
+		"moduleResolution": "bundler",
+		"isolatedModules": true,
+
+		"importHelpers": true,
+
+		"noUncheckedIndexedAccess": true,
+		"noImplicitOverride": true,
+		"noPropertyAccessFromIndexSignature": true,
+		"erasableSyntaxOnly": false,
+		"exactOptionalPropertyTypes": false,
+
+		// For ESLint to handle:
+		"allowUnreachableCode": true,
+		"allowUnusedLabels": true,
 	},
 	"include": [
 		"./src/**/*.ts"

version-bump.mjs

@@ -1,4 +1,5 @@
 import { readFileSync, writeFileSync } from "fs";
+import process from "process";
 
 const targetVersion = process.env.npm_package_version;
 

versions.json

@@ -1,4 +1,5 @@
 {
+	"0.6.1": "1.8.2",
 	"0.6.0": "1.8.0",
 	"0.5.1": "1.8.0",
 	"0.5.0": "1.8.0",