gecko-dev/uriloader/exthandler/WebHandlerApp.jsm

/* 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/. */

////////////////////////////////////////////////////////////////////////////////
//// Constants

const {XPCOMUtils} = ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
const {NetUtil} = ChromeUtils.import("resource://gre/modules/NetUtil.jsm");
const {Services} = ChromeUtils.import('resource://gre/modules/Services.jsm');

////////////////////////////////////////////////////////////////////////////////
//// nsWebHandler class

function nsWebHandlerApp() {}

nsWebHandlerApp.prototype = {
  //////////////////////////////////////////////////////////////////////////////
  //// nsWebHandler

  classDescription: "A web handler for protocols and content",
  classID: Components.ID("8b1ae382-51a9-4972-b930-56977a57919d"),
  contractID: "@mozilla.org/uriloader/web-handler-app;1",

  _name: null,
  _detailedDescription: null,
  _uriTemplate: null,

  //////////////////////////////////////////////////////////////////////////////
  //// nsIHandlerApp

  get name() {
    return this._name;
  },

  set name(aName) {
    this._name = aName;
  },

  get detailedDescription() {
    return this._detailedDescription;
  },

  set detailedDescription(aDesc) {
    this._detailedDescription = aDesc;
  },

  equals: function(aHandlerApp) {
    if (!aHandlerApp)
      throw Cr.NS_ERROR_NULL_POINTER;

    if (aHandlerApp instanceof Ci.nsIWebHandlerApp &&
        aHandlerApp.uriTemplate &&
        this.uriTemplate &&
        aHandlerApp.uriTemplate == this.uriTemplate)
      return true;

    return false;
  },

  launchWithURI: function nWHA__launchWithURI(aURI, aWindowContext) {

    // XXX need to strip passwd & username from URI to handle, as per the
    // WhatWG HTML5 draft.  nsSimpleURL, which is what we're going to get,
    // can't do this directly.  Ideally, we'd fix nsStandardURL to make it
    // possible to turn off all of its quirks handling, and use that...

    // encode the URI to be handled
    var escapedUriSpecToHandle = encodeURIComponent(aURI.spec);

    // insert the encoded URI and create the object version 
    var uriSpecToSend = this.uriTemplate.replace("%s", escapedUriSpecToHandle);
    var ioService = Cc["@mozilla.org/network/io-service;1"].
                    getService(Ci.nsIIOService);
    var uriToSend = ioService.newURI(uriSpecToSend);
    
    // if we have a window context, use the URI loader to load there
    if (aWindowContext) {
      try {
        // getInterface throws if the object doesn't implement the given
        // interface, so this try/catch statement is more of an if.
        // If aWindowContext refers to a remote docshell, send the load
        // request to the correct process.
        aWindowContext.getInterface(Ci.nsIRemoteWindowContext)
                      .openURI(uriToSend);
        return;
      } catch (e) {
        if (e.result != Cr.NS_NOINTERFACE) {
          throw e;
        }
      }

      // create a channel from this URI
      var channel = NetUtil.newChannel({
        uri: uriToSend,
        loadUsingSystemPrincipal: true
      });
      channel.loadFlags = Ci.nsIChannel.LOAD_DOCUMENT_URI;

      // load the channel
      var uriLoader = Cc["@mozilla.org/uriloader;1"].
                      getService(Ci.nsIURILoader);
      // XXX ideally, whether to pass the IS_CONTENT_PREFERRED flag should be
      // passed in from above.  Practically, the flag is probably a reasonable
      // default since browsers don't care much, and link click is likely to be
      // the more interesting case for non-browser apps.  See 
      // <https://bugzilla.mozilla.org/show_bug.cgi?id=392957#c9> for details.
      uriLoader.openURI(channel, Ci.nsIURILoader.IS_CONTENT_PREFERRED,
                        aWindowContext);
      return;
    } 

    // since we don't have a window context, hand it off to a browser
    var windowMediator = Cc["@mozilla.org/appshell/window-mediator;1"].
      getService(Ci.nsIWindowMediator);

    // get browser dom window
    var browserDOMWin = windowMediator.getMostRecentWindow("navigator:browser")
                        .QueryInterface(Ci.nsIDOMChromeWindow)
                        .browserDOMWindow;

    // if we got an exception, there are several possible reasons why:
    // a) this gecko embedding doesn't provide an nsIBrowserDOMWindow
    //    implementation (i.e. doesn't support browser-style functionality),
    //    so we need to kick the URL out to the OS default browser.  This is
    //    the subject of bug 394479.
    // b) this embedding does provide an nsIBrowserDOMWindow impl, but
    //    there doesn't happen to be a browser window open at the moment; one
    //    should be opened.  It's not clear whether this situation will really
    //    ever occur in real life.  If it does, the only API that I can find
    //    that seems reasonably likely to work for most embedders is the
    //    command line handler.  
    // c) something else went wrong 
    //
    // it's not clear how one would differentiate between the three cases
    // above, so for now we don't catch the exception

    // openURI
    browserDOMWin.openURI(uriToSend,
                          null, // no window.opener
                          Ci.nsIBrowserDOMWindow.OPEN_DEFAULTWINDOW,
                          Ci.nsIBrowserDOMWindow.OPEN_NEW,
                          Services.scriptSecurityManager.getSystemPrincipal());
      
    return;
  },

  //////////////////////////////////////////////////////////////////////////////
  //// nsIWebHandlerApp

  get uriTemplate() {
    return this._uriTemplate;
  },

  set uriTemplate(aURITemplate) {
    this._uriTemplate = aURITemplate;
  },

  //////////////////////////////////////////////////////////////////////////////
  //// nsISupports

  QueryInterface: ChromeUtils.generateQI([Ci.nsIWebHandlerApp, Ci.nsIHandlerApp])
};

var EXPORTED_SYMBOLS = ["nsWebHandlerApp"];