extract reusable userSettings library

src/vs/workbench/node/userSettings.ts

@@ -0,0 +1,178 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+
+'use strict';
+
+import fs = require('fs');
+import path = require('path');
+
+import json = require('vs/base/common/json');
+import objects = require('vs/base/common/objects');
+import {EventProvider} from 'vs/base/common/eventProvider';
+import {EventSource} from 'vs/base/common/eventSource';
+
+export interface ISettings {
+	settings: any;
+	settingsParseErrors?: string[];
+	keybindings: any
+}
+
+export class UserSettings {
+
+	private static CHANGE_BUFFER_DELAY = 300;
+
+	public globalSettings: ISettings;
+
+	private timeoutHandle: number;
+	private watcher: fs.FSWatcher;
+	private appSettingsPath: string;
+	private appKeybindingsPath: string;
+
+	private _onChange: EventSource<(settings: ISettings) => void>;
+
+	constructor(appSettingsPath:string, appKeybindingsPath: string) {
+		this.appSettingsPath = appSettingsPath;
+		this.appKeybindingsPath = appKeybindingsPath;
+		this._onChange = new EventSource<(settings: ISettings) => void>();
+
+		this.registerWatchers();
+	}
+
+	public get onChange(): EventProvider<(settings: ISettings) => void> {
+		return this._onChange.value;
+	}
+
+	public getValue(key: string, fallback?: any): any {
+		if (!key) {
+			return fallback;
+		}
+
+		let value = this.globalSettings.settings;
+
+		let parts = key.split('\.');
+		while (parts.length && value) {
+			let part = parts.shift();
+			value = value[part];
+		}
+
+		return typeof value !== 'undefined' ? value : fallback;
+	}
+
+	private registerWatchers(): void {
+		this.watcher = fs.watch(path.dirname(this.appSettingsPath));
+		this.watcher.on('change', (eventType: string, fileName: string) => this.onSettingsFileChange(eventType, fileName));
+	}
+
+	private onSettingsFileChange(eventType: string, fileName: string): void {
+
+		// we can get multiple change events for one change, so we buffer through a timeout
+		if (this.timeoutHandle) {
+			global.clearTimeout(this.timeoutHandle);
+			delete this.timeoutHandle;
+		}
+
+		this.timeoutHandle = global.setTimeout(() => {
+
+			// Reload
+			let didChange = this.load();
+
+			// Emit event
+			if (didChange) {
+				this._onChange.fire(this.globalSettings);
+			}
+
+		}, UserSettings.CHANGE_BUFFER_DELAY);
+	}
+
+	public load(): boolean {
+		let loadedSettings = this.doLoad();
+		if (!objects.equals(loadedSettings, this.globalSettings)) {
+
+			// Keep in class
+			this.globalSettings = loadedSettings;
+
+			return true; // changed value
+		}
+
+		return false; // no changed value
+	}
+
+	private doLoad(): ISettings {
+		let settings = this.doLoadSettings();
+
+		return {
+			settings: settings.contents,
+			settingsParseErrors: settings.parseErrors,
+			keybindings: this.doLoadKeybindings()
+		};
+	}
+
+	private doLoadSettings(): { contents: any; parseErrors?: string[]; } {
+
+		function setNode(root: any, key: string, value: any): any {
+			let segments = key.split('.');
+			let last = segments.pop();
+
+			let curr = root;
+			segments.forEach((s) => {
+				let obj = curr[s];
+				switch (typeof obj) {
+					case 'undefined':
+						obj = curr[s] = {};
+						break;
+					case 'object':
+						break;
+					default:
+						console.log('Conflicting user settings: ' + key + ' at ' + s + ' with ' + JSON.stringify(obj));
+				}
+				curr = obj;
+			});
+			curr[last] = value;
+		}
+
+
+		try {
+			let root = {};
+			let content = '{}';
+			try {
+				content = fs.readFileSync(this.appSettingsPath).toString();
+			} catch (error) {
+				// ignore
+			}
+
+			let contents = json.parse(content) || {};
+			for (let key in contents) {
+				setNode(root, key, contents[key]);
+			}
+			return {
+				contents: root
+			};
+		} catch (error) {
+			// parse problem
+			return {
+				contents: {},
+				parseErrors: [this.appSettingsPath]
+			};
+		}
+	}
+
+	private doLoadKeybindings(): any {
+		try {
+			return json.parse(fs.readFileSync(this.appKeybindingsPath).toString());
+		} catch (error) {
+			// Ignore loading and parsing errors
+		}
+
+		return [];
+	}
+
+	public dispose(): void {
+		if (this.watcher) {
+			this.watcher.close();
+			this.watcher = null;
+		}
+	}
+}