SQL Operations Studio Public Preview 1 (0.23) release source code

extensions/markdown/src/tableOfContentsProvider.ts

@@ -0,0 +1,94 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the Source EULA. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+'use strict';
+
+import * as vscode from 'vscode';
+
+import { MarkdownEngine } from './markdownEngine';
+
+export interface TocEntry {
+	slug: string;
+	text: string;
+	level: number;
+	line: number;
+	location: vscode.Location;
+}
+
+export class TableOfContentsProvider {
+	private toc: TocEntry[];
+
+	public constructor(
+		private engine: MarkdownEngine,
+		private document: vscode.TextDocument
+	) { }
+
+	public async getToc(): Promise<TocEntry[]> {
+		if (!this.toc) {
+			try {
+				this.toc = await this.buildToc(this.document);
+			} catch (e) {
+				this.toc = [];
+			}
+		}
+		return this.toc;
+	}
+
+	public async lookup(fragment: string): Promise<number> {
+		const slug = TableOfContentsProvider.slugify(fragment);
+		for (const entry of await this.getToc()) {
+			if (entry.slug === slug) {
+				return entry.line;
+			}
+		}
+		return NaN;
+	}
+
+	private async buildToc(document: vscode.TextDocument): Promise<TocEntry[]> {
+		const toc: TocEntry[] = [];
+		const tokens = await this.engine.parse(document.uri, document.getText());
+
+		for (const heading of tokens.filter(token => token.type === 'heading_open')) {
+			const lineNumber = heading.map[0];
+			const line = document.lineAt(lineNumber);
+			const href = TableOfContentsProvider.slugify(line.text);
+			const level = TableOfContentsProvider.getHeaderLevel(heading.markup);
+			if (href) {
+				toc.push({
+					slug: href,
+					text: TableOfContentsProvider.getHeaderText(line.text),
+					level: level,
+					line: lineNumber,
+					location: new vscode.Location(document.uri, line.range)
+				});
+			}
+		}
+		return toc;
+	}
+
+	private static getHeaderLevel(markup: string): number {
+		if (markup === '=') {
+			return 1;
+		} else if (markup === '-') {
+			return 2;
+		} else { // '#', '##', ...
+			return markup.length;
+		}
+	}
+
+	private static getHeaderText(header: string): string {
+		return header.replace(/^\s*#+\s*(.*?)\s*\1*$/, (_, word) => `${word.trim()}`);
+	}
+
+	public static slugify(header: string): string {
+		return encodeURI(header.trim()
+			.toLowerCase()
+			.replace(/[\]\[\!\"\#\$\%\&\'\(\)\*\+\,\.\/\:\;\<\=\>\?\@\\\^\_\{\|\}\~\`]/g, '')
+			.replace(/\s+/g, '-')
+			.replace(/^\-+/, '')
+			.replace(/\-+$/, ''));
+	}
+}
+