1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/addon-sdk/source/lib/sdk/content/worker.js Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,282 @@
1.4 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.5 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.6 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.7 +"use strict";
1.8 +
1.9 +module.metadata = {
1.10 + "stability": "unstable"
1.11 +};
1.12 +
1.13 +const { Class } = require('../core/heritage');
1.14 +const { EventTarget } = require('../event/target');
1.15 +const { on, off, emit, setListeners } = require('../event/core');
1.16 +const {
1.17 + attach, detach, destroy
1.18 +} = require('./utils');
1.19 +const { method } = require('../lang/functional');
1.20 +const { Ci, Cu, Cc } = require('chrome');
1.21 +const unload = require('../system/unload');
1.22 +const events = require('../system/events');
1.23 +const { getInnerId } = require("../window/utils");
1.24 +const { WorkerSandbox } = require('./sandbox');
1.25 +const { getTabForWindow } = require('../tabs/helpers');
1.26 +
1.27 +// A weak map of workers to hold private attributes that
1.28 +// should not be exposed
1.29 +const workers = new WeakMap();
1.30 +
1.31 +let modelFor = (worker) => workers.get(worker);
1.32 +
1.33 +const ERR_DESTROYED =
1.34 + "Couldn't find the worker to receive this message. " +
1.35 + "The script may not be initialized yet, or may already have been unloaded.";
1.36 +
1.37 +const ERR_FROZEN = "The page is currently hidden and can no longer be used " +
1.38 + "until it is visible again.";
1.39 +
1.40 +/**
1.41 + * Message-passing facility for communication between code running
1.42 + * in the content and add-on process.
1.43 + * @see https://addons.mozilla.org/en-US/developers/docs/sdk/latest/modules/sdk/content/worker.html
1.44 + */
1.45 +const Worker = Class({
1.46 + implements: [EventTarget],
1.47 + initialize: function WorkerConstructor (options) {
1.48 + // Save model in weak map to not expose properties
1.49 + let model = createModel();
1.50 + workers.set(this, model);
1.51 +
1.52 + options = options || {};
1.53 +
1.54 + if ('contentScriptFile' in options)
1.55 + this.contentScriptFile = options.contentScriptFile;
1.56 + if ('contentScriptOptions' in options)
1.57 + this.contentScriptOptions = options.contentScriptOptions;
1.58 + if ('contentScript' in options)
1.59 + this.contentScript = options.contentScript;
1.60 + if ('injectInDocument' in options)
1.61 + this.injectInDocument = !!options.injectInDocument;
1.62 +
1.63 + setListeners(this, options);
1.64 +
1.65 + unload.ensure(this, "destroy");
1.66 +
1.67 + // Ensure that worker.port is initialized for contentWorker to be able
1.68 + // to send events during worker initialization.
1.69 + this.port = createPort(this);
1.70 +
1.71 + model.documentUnload = documentUnload.bind(this);
1.72 + model.pageShow = pageShow.bind(this);
1.73 + model.pageHide = pageHide.bind(this);
1.74 +
1.75 + if ('window' in options)
1.76 + attach(this, options.window);
1.77 + },
1.78 +
1.79 + /**
1.80 + * Sends a message to the worker's global scope. Method takes single
1.81 + * argument, which represents data to be sent to the worker. The data may
1.82 + * be any primitive type value or `JSON`. Call of this method asynchronously
1.83 + * emits `message` event with data value in the global scope of this
1.84 + * symbiont.
1.85 + *
1.86 + * `message` event listeners can be set either by calling
1.87 + * `self.on` with a first argument string `"message"` or by
1.88 + * implementing `onMessage` function in the global scope of this worker.
1.89 + * @param {Number|String|JSON} data
1.90 + */
1.91 + postMessage: function (...data) {
1.92 + let model = modelFor(this);
1.93 + let args = ['message'].concat(data);
1.94 + if (!model.inited) {
1.95 + model.earlyEvents.push(args);
1.96 + return;
1.97 + }
1.98 + processMessage.apply(null, [this].concat(args));
1.99 + },
1.100 +
1.101 + get url () {
1.102 + let model = modelFor(this);
1.103 + // model.window will be null after detach
1.104 + return model.window ? model.window.document.location.href : null;
1.105 + },
1.106 +
1.107 + get contentURL () {
1.108 + let model = modelFor(this);
1.109 + return model.window ? model.window.document.URL : null;
1.110 + },
1.111 +
1.112 + get tab () {
1.113 + let model = modelFor(this);
1.114 + // model.window will be null after detach
1.115 + if (model.window)
1.116 + return getTabForWindow(model.window);
1.117 + return null;
1.118 + },
1.119 +
1.120 + // Implemented to provide some of the previous features of exposing sandbox
1.121 + // so that Worker can be extended
1.122 + getSandbox: function () {
1.123 + return modelFor(this).contentWorker;
1.124 + },
1.125 +
1.126 + toString: function () { return '[object Worker]'; },
1.127 + attach: method(attach),
1.128 + detach: method(detach),
1.129 + destroy: method(destroy)
1.130 +});
1.131 +exports.Worker = Worker;
1.132 +
1.133 +attach.define(Worker, function (worker, window) {
1.134 + let model = modelFor(worker);
1.135 + model.window = window;
1.136 + // Track document unload to destroy this worker.
1.137 + // We can't watch for unload event on page's window object as it
1.138 + // prevents bfcache from working:
1.139 + // https://developer.mozilla.org/En/Working_with_BFCache
1.140 + model.windowID = getInnerId(model.window);
1.141 + events.on("inner-window-destroyed", model.documentUnload);
1.142 +
1.143 + // Listen to pagehide event in order to freeze the content script
1.144 + // while the document is frozen in bfcache:
1.145 + model.window.addEventListener("pageshow", model.pageShow, true);
1.146 + model.window.addEventListener("pagehide", model.pageHide, true);
1.147 +
1.148 + // will set model.contentWorker pointing to the private API:
1.149 + model.contentWorker = WorkerSandbox(worker, model.window);
1.150 +
1.151 + // Mainly enable worker.port.emit to send event to the content worker
1.152 + model.inited = true;
1.153 + model.frozen = false;
1.154 +
1.155 + // Fire off `attach` event
1.156 + emit(worker, 'attach', window);
1.157 +
1.158 + // Process all events and messages that were fired before the
1.159 + // worker was initialized.
1.160 + model.earlyEvents.forEach(args => processMessage.apply(null, [worker].concat(args)));
1.161 +});
1.162 +
1.163 +/**
1.164 + * Remove all internal references to the attached document
1.165 + * Tells _port to unload itself and removes all the references from itself.
1.166 + */
1.167 +detach.define(Worker, function (worker, reason) {
1.168 + let model = modelFor(worker);
1.169 +
1.170 + // maybe unloaded before content side is created
1.171 + if (model.contentWorker) {
1.172 + model.contentWorker.destroy(reason);
1.173 + }
1.174 +
1.175 + model.contentWorker = null;
1.176 + if (model.window) {
1.177 + model.window.removeEventListener("pageshow", model.pageShow, true);
1.178 + model.window.removeEventListener("pagehide", model.pageHide, true);
1.179 + }
1.180 + model.window = null;
1.181 + // This method may be called multiple times,
1.182 + // avoid dispatching `detach` event more than once
1.183 + if (model.windowID) {
1.184 + model.windowID = null;
1.185 + events.off("inner-window-destroyed", model.documentUnload);
1.186 + model.earlyEvents.length = 0;
1.187 + emit(worker, 'detach');
1.188 + }
1.189 + model.inited = false;
1.190 +});
1.191 +
1.192 +/**
1.193 + * Tells content worker to unload itself and
1.194 + * removes all the references from itself.
1.195 + */
1.196 +destroy.define(Worker, function (worker, reason) {
1.197 + detach(worker, reason);
1.198 + modelFor(worker).inited = true;
1.199 + // Specifying no type or listener removes all listeners
1.200 + // from target
1.201 + off(worker);
1.202 +});
1.203 +
1.204 +/**
1.205 + * Events fired by workers
1.206 + */
1.207 +function documentUnload ({ subject, data }) {
1.208 + let model = modelFor(this);
1.209 + let innerWinID = subject.QueryInterface(Ci.nsISupportsPRUint64).data;
1.210 + if (innerWinID != model.windowID) return false;
1.211 + detach(this);
1.212 + return true;
1.213 +}
1.214 +
1.215 +function pageShow () {
1.216 + let model = modelFor(this);
1.217 + model.contentWorker.emitSync('pageshow');
1.218 + emit(this, 'pageshow');
1.219 + model.frozen = false;
1.220 +}
1.221 +
1.222 +function pageHide () {
1.223 + let model = modelFor(this);
1.224 + model.contentWorker.emitSync('pagehide');
1.225 + emit(this, 'pagehide');
1.226 + model.frozen = true;
1.227 +}
1.228 +
1.229 +/**
1.230 + * Fired from postMessage and emitEventToContent, or from the earlyMessage
1.231 + * queue when fired before the content is loaded. Sends arguments to
1.232 + * contentWorker if able
1.233 + */
1.234 +
1.235 +function processMessage (worker, ...args) {
1.236 + let model = modelFor(worker) || {};
1.237 + if (!model.contentWorker)
1.238 + throw new Error(ERR_DESTROYED);
1.239 + if (model.frozen)
1.240 + throw new Error(ERR_FROZEN);
1.241 + model.contentWorker.emit.apply(null, args);
1.242 +}
1.243 +
1.244 +function createModel () {
1.245 + return {
1.246 + // List of messages fired before worker is initialized
1.247 + earlyEvents: [],
1.248 + // Is worker connected to the content worker sandbox ?
1.249 + inited: false,
1.250 + // Is worker being frozen? i.e related document is frozen in bfcache.
1.251 + // Content script should not be reachable if frozen.
1.252 + frozen: true,
1.253 + /**
1.254 + * Reference to the content side of the worker.
1.255 + * @type {WorkerGlobalScope}
1.256 + */
1.257 + contentWorker: null,
1.258 + /**
1.259 + * Reference to the window that is accessible from
1.260 + * the content scripts.
1.261 + * @type {Object}
1.262 + */
1.263 + window: null
1.264 + };
1.265 +}
1.266 +
1.267 +function createPort (worker) {
1.268 + let port = EventTarget();
1.269 + port.emit = emitEventToContent.bind(null, worker);
1.270 + return port;
1.271 +}
1.272 +
1.273 +/**
1.274 + * Emit a custom event to the content script,
1.275 + * i.e. emit this event on `self.port`
1.276 + */
1.277 +function emitEventToContent (worker, ...eventArgs) {
1.278 + let model = modelFor(worker);
1.279 + let args = ['event'].concat(eventArgs);
1.280 + if (!model.inited) {
1.281 + model.earlyEvents.push(args);
1.282 + return;
1.283 + }
1.284 + processMessage.apply(null, [worker].concat(args));
1.285 +}
