gecko-dev/testing/marionette/proxy.js

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6.4 KiB
JavaScript
Исходник Ответственный История

Этот файл содержит невидимые символы Юникода!

Этот файл содержит невидимые символы Юникода, которые могут быть отображены не так, как показано ниже. Если это намеренно, можете спокойно проигнорировать это предупреждение. Используйте кнопку Экранировать, чтобы показать скрытые символы.

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
"use strict";
const {classes: Cc, interfaces: Ci, utils: Cu} = Components;
Cu.import("resource://gre/modules/Log.jsm");
Cu.import("chrome://marionette/content/modal.js");
this.EXPORTED_SYMBOLS = ["proxy"];
const MARIONETTE_OK = "Marionette:ok";
const MARIONETTE_DONE = "Marionette:done";
const MARIONETTE_ERROR = "Marionette:error";
const logger = Log.repository.getLogger("Marionette");
const uuidgen = Cc["@mozilla.org/uuid-generator;1"].getService(Ci.nsIUUIDGenerator);
// Proxy handler that traps requests to get a property. Will prioritise
// properties that exist on the object's own prototype.
var ownPriorityGetterTrap = {
get: (obj, prop) => {
if (obj.hasOwnProperty(prop)) {
return obj[prop];
}
return (...args) => obj.send(prop, args);
}
};
this.proxy = {};
/**
* Creates a transparent interface between the chrome- and content
* contexts.
*
* Calls to this object will be proxied via the message manager to the active
* browsing context (content) and responses will be provided back as
* promises.
*
* The argument sequence is serialised and passed as an array, unless it
* consists of a single object type that isn't null, in which case it's
* passed literally. The latter specialisation is temporary to achieve
* backwards compatibility with listener.js.
*
* @param {function(): (nsIMessageSender|nsIMessageBroadcaster)} mmFn
* Function returning the current message manager.
* @param {function(string, Object, number)} sendAsyncFn
* Callback for sending async messages to the current listener.
*/
proxy.toListener = function(mmFn, sendAsyncFn) {
let sender = new AsyncContentSender(mmFn, sendAsyncFn);
return new Proxy(sender, ownPriorityGetterTrap);
};
/**
* The AsyncContentSender allows one to make synchronous calls to the
* message listener of the content frame of the current browsing context.
*
* Presumptions about the responses from content space are made so we
* can provide a nicer API on top of the message listener primitives that
* make calls from chrome- to content space seem synchronous by leveraging
* promises.
*
* The promise is guaranteed not to resolve until the execution of the
* command in content space is complete.
*/
this.AsyncContentSender = class {
constructor(mmFn, sendAsyncFn) {
this.curId = null;
this.sendAsync = sendAsyncFn;
this.mmFn_ = mmFn;
this._listeners = [];
}
get mm() {
return this.mmFn_();
}
removeListeners() {
this._listeners.map(l => this.mm.removeMessageListener(l[0], l[1]));
this._listeners = [];
}
/**
* Call registered function in the frame script environment of the
* current browsing context's content frame.
*
* @param {string} name
* Function to call in the listener, e.g. for "Marionette:foo8",
* use "foo".
* @param {Array} args
* Argument list to pass the function. If args has a single entry
* that is an object, we assume it's an old style dispatch, and
* the object will passed literally.
*
* @return {Promise}
* A promise that resolves to the result of the command.
*/
send(name, args) {
if (this._listeners[0]) {
// A prior (probably timed-out) request has left listeners behind.
// Remove them before proceeding.
logger.warn("A previous failed command left content listeners behind!");
this.removeListeners();
}
this.curId = uuidgen.generateUUID().toString();
let proxy = new Promise((resolve, reject) => {
let removeListeners = (n, fn) => {
let rmFn = msg => {
if (this.curId !== msg.json.command_id) {
logger.warn("Skipping out-of-sync response from listener: " +
`Expected response to ${name} with ID ${this.curId}, ` +
"but got: " + msg.name + msg.json.toSource());
return;
}
this.removeListeners();
modal.removeHandler(handleDialog);
fn(msg);
this.curId = null;
};
this._listeners.push([n, rmFn]);
return rmFn;
};
let okListener = () => resolve();
let valListener = msg => resolve(msg.json.value);
let errListener = msg => reject(msg.objects.error);
let handleDialog = (subject, topic) => {
this.removeListeners()
modal.removeHandler(handleDialog);
this.sendAsync("cancelRequest");
resolve();
};
// start content process listeners, and install observers for global-
// and tab modal dialogues
this.mm.addMessageListener(MARIONETTE_OK, removeListeners(MARIONETTE_OK, okListener));
this.mm.addMessageListener(MARIONETTE_DONE, removeListeners(MARIONETTE_DONE, valListener));
this.mm.addMessageListener(MARIONETTE_ERROR, removeListeners(MARIONETTE_ERROR, errListener));
modal.addHandler(handleDialog);
this.sendAsync(name, marshal(args), this.curId);
});
return proxy;
}
};
/**
* Creates a transparent interface from the content- to the chrome context.
*
* Calls to this object will be proxied via the frame's sendSyncMessage
* (nsISyncMessageSender) function. Since the message is synchronous,
* the return value is presented as a return value.
*
* Example on how to use from a frame content script:
*
* let chrome = proxy.toChrome(sendSyncMessage.bind(this));
* let cookie = chrome.getCookie("foo");
*
* @param {nsISyncMessageSender} sendSyncMessageFn
* The frame message manager's sendSyncMessage function.
*/
proxy.toChrome = function(sendSyncMessageFn) {
let sender = new SyncChromeSender(sendSyncMessageFn);
return new Proxy(sender, ownPriorityGetterTrap);
};
/**
* The SyncChromeSender sends synchronous RPC messages to the chrome
* context, using a frame's sendSyncMessage (nsISyncMessageSender) function.
*
* Example on how to use from a frame content script:
*
* let sender = new SyncChromeSender(sendSyncMessage.bind(this));
* let res = sender.send("addCookie", cookie);
*/
this.SyncChromeSender = class {
constructor(sendSyncMessage) {
this.sendSyncMessage_ = sendSyncMessage;
}
send(func, args) {
let name = "Marionette:" + func;
return this.sendSyncMessage_(name, marshal(args));
}
};
var marshal = function(args) {
if (args.length == 1 && typeof args[0] == "object") {
return args[0];
}
return args;
};