gecko-dev/b2g/components/YoutubeProtocolHandler.js

126 lines
4.0 KiB
JavaScript

/* 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 Cc = Components.classes;
const Ci = Components.interfaces;
const Cu = Components.utils;
Cu.import("resource://gre/modules/XPCOMUtils.jsm");
Cu.import("resource://gre/modules/Services.jsm");
XPCOMUtils.defineLazyGetter(this, "cpmm", function() {
return Cc["@mozilla.org/childprocessmessagemanager;1"]
.getService(Ci.nsIMessageSender);
});
// Splits parameters in a query string.
function extractParameters(aQuery) {
let params = aQuery.split("&");
let res = {};
params.forEach(function(aParam) {
let obj = aParam.split("=");
res[obj[0]] = decodeURIComponent(obj[1]);
});
return res;
}
function YoutubeProtocolHandler() {
}
YoutubeProtocolHandler.prototype = {
classID: Components.ID("{c3f1b945-7e71-49c8-95c7-5ae9cc9e2bad}"),
QueryInterface: XPCOMUtils.generateQI([Ci.nsIProtocolHandler]),
scheme: "vnd.youtube",
defaultPort: -1,
protocolFlags: Ci.nsIProtocolHandler.URI_NORELATIVE |
Ci.nsIProtocolHandler.URI_NOAUTH |
Ci.nsIProtocolHandler.URI_LOADABLE_BY_ANYONE,
// Sample URL:
// vnd.youtube:iNuKL2Gy_QM?vndapp=youtube_mobile&vndclient=mv-google&vndel=watch&vnddnc=1
newURI: function yt_phNewURI(aSpec, aOriginCharset, aBaseURI) {
let uri = Cc["@mozilla.org/network/standard-url;1"]
.createInstance(Ci.nsIStandardURL);
let id = aSpec.substring(this.scheme.length + 1);
id = id.substring(0, id.indexOf('?'));
uri.init(Ci.nsIStandardURL.URLTYPE_STANDARD, -1, this.scheme + "://dummy_host/" + id, aOriginCharset,
aBaseURI);
return uri.QueryInterface(Ci.nsIURI);
},
newChannel: function yt_phNewChannel(aURI) {
// Get a list of streams for this video id.
let infoURI = "http://www.youtube.com/get_video_info?&video_id=" +
aURI.path.substring(1);
let xhr = Cc["@mozilla.org/xmlextras/xmlhttprequest;1"]
.createInstance(Ci.nsIXMLHttpRequest);
xhr.open("GET", infoURI, true);
xhr.addEventListener("load", function() {
// Youtube sends the response as a double wrapped url answer:
// we first extract the url_encoded_fmt_stream_map parameter,
// and from each comma-separated entry in this value, we extract
// other parameters (url and type).
let key = "url_encoded_fmt_stream_map=";
let pos = xhr.responseText.indexOf(key);
if (pos == -1) {
return;
}
let streams = decodeURIComponent(xhr.responseText
.substring(pos + key.length)).split(",");
let uri;
let mimeType;
// Recognized mime types, ordered from the less usable to the most usable.
let recognizedTypes = ["video/webm"];
#ifdef MOZ_WIDGET_GONK
recognizedTypes.push("video/mp4");
#endif
let bestType = -1;
let extras = { }
streams.forEach(function(aStream) {
let params = extractParameters(aStream);
let url = params["url"];
let type = params["type"] ? params["type"].split(";")[0] : null;
let index;
if (url && type && ((index = recognizedTypes.indexOf(type)) != -1) &&
index > bestType) {
uri = url;
mimeType = type;
bestType = index;
}
for (let param in params) {
if (["thumbnail_url", "length_seconds", "title"].indexOf(param) != -1) {
extras[param] = decodeURIComponent(params[param]);
}
}
});
if (uri && mimeType) {
cpmm.sendAsyncMessage("content-handler", {
url: uri,
type: mimeType,
extras: extras
});
}
});
xhr.send(null);
throw Components.results.NS_ERROR_ILLEGAL_VALUE;
},
allowPort: function yt_phAllowPort(aPort, aScheme) {
return false;
}
};
const NSGetFactory = XPCOMUtils.generateNSGetFactory([YoutubeProtocolHandler]);