summaryrefslogtreecommitdiffstats
path: root/application/basilisk/base/content/browser-feeds.js
blob: 6f29d89153cc7f87d8dc25ab983a61cc69c58fb2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*-
 * 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/. */

XPCOMUtils.defineLazyModuleGetter(this, "DeferredTask",
                                  "resource://gre/modules/DeferredTask.jsm");

const TYPE_MAYBE_FEED = "application/vnd.mozilla.maybe.feed";
const TYPE_MAYBE_AUDIO_FEED = "application/vnd.mozilla.maybe.audio.feed";
const TYPE_MAYBE_VIDEO_FEED = "application/vnd.mozilla.maybe.video.feed";

const PREF_SHOW_FIRST_RUN_UI = "browser.feeds.showFirstRunUI";

const PREF_SELECTED_APP = "browser.feeds.handlers.application";
const PREF_SELECTED_WEB = "browser.feeds.handlers.webservice";
const PREF_SELECTED_ACTION = "browser.feeds.handler";
const PREF_SELECTED_READER = "browser.feeds.handler.default";

const PREF_VIDEO_SELECTED_APP = "browser.videoFeeds.handlers.application";
const PREF_VIDEO_SELECTED_WEB = "browser.videoFeeds.handlers.webservice";
const PREF_VIDEO_SELECTED_ACTION = "browser.videoFeeds.handler";
const PREF_VIDEO_SELECTED_READER = "browser.videoFeeds.handler.default";

const PREF_AUDIO_SELECTED_APP = "browser.audioFeeds.handlers.application";
const PREF_AUDIO_SELECTED_WEB = "browser.audioFeeds.handlers.webservice";
const PREF_AUDIO_SELECTED_ACTION = "browser.audioFeeds.handler";
const PREF_AUDIO_SELECTED_READER = "browser.audioFeeds.handler.default";

const PREF_UPDATE_DELAY = 2000;

const SETTABLE_PREFS = new Set([
  PREF_VIDEO_SELECTED_ACTION,
  PREF_AUDIO_SELECTED_ACTION,
  PREF_SELECTED_ACTION,
  PREF_VIDEO_SELECTED_READER,
  PREF_AUDIO_SELECTED_READER,
  PREF_SELECTED_READER,
  PREF_VIDEO_SELECTED_WEB,
  PREF_AUDIO_SELECTED_WEB,
  PREF_SELECTED_WEB
]);

const EXECUTABLE_PREFS = new Set([
  PREF_SELECTED_APP,
  PREF_VIDEO_SELECTED_APP,
  PREF_AUDIO_SELECTED_APP
]);

const VALID_ACTIONS = new Set(["ask", "reader", "bookmarks"]);
const VALID_READERS = new Set(["web", "client", "default", "bookmarks"]);

XPCOMUtils.defineLazyPreferenceGetter(this, "SHOULD_LOG",
                                      "feeds.log", false);

function LOG(str) {
  if (SHOULD_LOG)
    dump("*** Feeds: " + str + "\n");
}

function getPrefActionForType(t) {
  switch (t) {
    case Ci.nsIFeed.TYPE_VIDEO:
      return PREF_VIDEO_SELECTED_ACTION;

    case Ci.nsIFeed.TYPE_AUDIO:
      return PREF_AUDIO_SELECTED_ACTION;

    default:
      return PREF_SELECTED_ACTION;
  }
}

function getPrefReaderForType(t) {
  switch (t) {
    case Ci.nsIFeed.TYPE_VIDEO:
      return PREF_VIDEO_SELECTED_READER;

    case Ci.nsIFeed.TYPE_AUDIO:
      return PREF_AUDIO_SELECTED_READER;

    default:
      return PREF_SELECTED_READER;
  }
}

function getPrefWebForType(t) {
  switch (t) {
    case Ci.nsIFeed.TYPE_VIDEO:
      return PREF_VIDEO_SELECTED_WEB;

    case Ci.nsIFeed.TYPE_AUDIO:
      return PREF_AUDIO_SELECTED_WEB;

    default:
      return PREF_SELECTED_WEB;
  }
}

function getPrefAppForType(t) {
  switch (t) {
    case Ci.nsIFeed.TYPE_VIDEO:
      return PREF_VIDEO_SELECTED_APP;

    case Ci.nsIFeed.TYPE_AUDIO:
      return PREF_AUDIO_SELECTED_APP;

    default:
      return PREF_SELECTED_APP;
  }
}

/**
 * Maps a feed type to a maybe-feed mimetype.
 */
function getMimeTypeForFeedType(aFeedType) {
  switch (aFeedType) {
    case Ci.nsIFeed.TYPE_VIDEO:
      return TYPE_MAYBE_VIDEO_FEED;

    case Ci.nsIFeed.TYPE_AUDIO:
      return TYPE_MAYBE_AUDIO_FEED;

    default:
      return TYPE_MAYBE_FEED;
  }
}

/**
 * The Feed Handler object manages discovery of RSS/ATOM feeds in web pages
 * and shows UI when they are discovered.
 */
var FeedHandler = {
  _prefChangeCallback: null,

  /** Called when the user clicks on the Subscribe to This Page... menu item,
   * or when the user clicks the feed button when the page contains multiple
   * feeds.
   * Builds a menu of unique feeds associated with the page, and if there
   * is only one, shows the feed inline in the browser window.
   * @param   container
   *          The feed list container (menupopup or subview) to be populated.
   * @param   isSubview
   *          Whether we're creating a subview (true) or menu (false/undefined)
   * @return  true if the menu/subview should be shown, false if there was only
   *          one feed and the feed should be shown inline in the browser
   *          window (do not show the menupopup/subview).
   */
  buildFeedList(container, isSubview) {
    let feeds = gBrowser.selectedBrowser.feeds;
    if (!isSubview && feeds == null) {
      // XXX hack -- menu opening depends on setting of an "open"
      // attribute, and the menu refuses to open if that attribute is
      // set (because it thinks it's already open).  onpopupshowing gets
      // called after the attribute is unset, and it doesn't get unset
      // if we return false.  so we unset it here; otherwise, the menu
      // refuses to work past this point.
      container.parentNode.removeAttribute("open");
      return false;
    }

    for (let i = container.childNodes.length - 1; i >= 0; --i) {
      let node = container.childNodes[i];
      if (isSubview && node.localName == "label")
        continue;
      container.removeChild(node);
    }

    if (!feeds || feeds.length <= 1)
      return false;

    // Build the menu showing the available feed choices for viewing.
    let itemNodeType = isSubview ? "toolbarbutton" : "menuitem";
    for (let feedInfo of feeds) {
      let item = document.createElement(itemNodeType);
      let baseTitle = feedInfo.title || feedInfo.href;
      item.setAttribute("label", baseTitle);
      item.setAttribute("feed", feedInfo.href);
      item.setAttribute("tooltiptext", feedInfo.href);
      item.setAttribute("crop", "center");
      let className = "feed-" + itemNodeType;
      if (isSubview) {
        className += " subviewbutton";
      }
      item.setAttribute("class", className);
      container.appendChild(item);
    }
    return true;
  },

  /**
   * Subscribe to a given feed.  Called when
   *   1. Page has a single feed and user clicks feed icon in location bar
   *   2. Page has a single feed and user selects Subscribe menu item
   *   3. Page has multiple feeds and user selects from feed icon popup (or subview)
   *   4. Page has multiple feeds and user selects from Subscribe submenu
   * @param   href
   *          The feed to subscribe to. May be null, in which case the
   *          event target's feed attribute is examined.
   * @param   event
   *          The event this method is handling. Used to decide where
   *          to open the preview UI. (Optional, unless href is null)
   */
  subscribeToFeed(href, event) {
    // Just load the feed in the content area to either subscribe or show the
    // preview UI
    if (!href)
      href = event.target.getAttribute("feed");
    urlSecurityCheck(href, gBrowser.contentPrincipal,
                     Ci.nsIScriptSecurityManager.DISALLOW_INHERIT_PRINCIPAL);
    let feedURI = makeURI(href, document.characterSet);
    // Use the feed scheme so X-Moz-Is-Feed will be set
    // The value doesn't matter
    if (/^https?$/.test(feedURI.scheme))
      href = "feed:" + href;
    this.loadFeed(href, event);
  },

  loadFeed(href, event) {
    let feeds = gBrowser.selectedBrowser.feeds;
    try {
      openUILink(href, event, { ignoreAlt: true });
    }
    finally {
      // We might default to a livebookmarks modal dialog,
      // so reset that if the user happens to click it again
      gBrowser.selectedBrowser.feeds = feeds;
    }
  },

  get _feedMenuitem() {
    delete this._feedMenuitem;
    return this._feedMenuitem = document.getElementById("singleFeedMenuitemState");
  },

  get _feedMenupopup() {
    delete this._feedMenupopup;
    return this._feedMenupopup = document.getElementById("multipleFeedsMenuState");
  },

  /**
   * Update the browser UI to show whether or not feeds are available when
   * a page is loaded or the user switches tabs to a page that has feeds.
   */
  updateFeeds() {
    if (this._updateFeedTimeout)
      clearTimeout(this._updateFeedTimeout);

    let feeds = gBrowser.selectedBrowser.feeds;
    let haveFeeds = feeds && feeds.length > 0;

    let feedButton = document.getElementById("feed-button");
    if (feedButton) {
      if (haveFeeds) {
        feedButton.removeAttribute("disabled");
      } else {
        feedButton.setAttribute("disabled", "true");
      }
    }

    if (!haveFeeds) {
      this._feedMenuitem.setAttribute("disabled", "true");
      this._feedMenuitem.removeAttribute("hidden");
      this._feedMenupopup.setAttribute("hidden", "true");
      return;
    }

    if (feeds.length > 1) {
      this._feedMenuitem.setAttribute("hidden", "true");
      this._feedMenupopup.removeAttribute("hidden");
    } else {
      this._feedMenuitem.setAttribute("feed", feeds[0].href);
      this._feedMenuitem.removeAttribute("disabled");
      this._feedMenuitem.removeAttribute("hidden");
      this._feedMenupopup.setAttribute("hidden", "true");
    }
  },

  addFeed(link, browserForLink) {
    if (!browserForLink.feeds)
      browserForLink.feeds = [];

    browserForLink.feeds.push({ href: link.href, title: link.title });

    // If this addition was for the current browser, update the UI. For
    // background browsers, we'll update on tab switch.
    if (browserForLink == gBrowser.selectedBrowser) {
      // Batch updates to avoid updating the UI for multiple onLinkAdded events
      // fired within 100ms of each other.
      if (this._updateFeedTimeout)
        clearTimeout(this._updateFeedTimeout);
      this._updateFeedTimeout = setTimeout(this.updateFeeds.bind(this), 100);
    }
  },

   /**
   * Get the human-readable display name of a file. This could be the
   * application name.
   * @param   file
   *          A nsIFile to look up the name of
   * @return  The display name of the application represented by the file.
   */
  _getFileDisplayName(file) {
    switch (AppConstants.platform) {
      case "win":
        if (file instanceof Ci.nsILocalFileWin) {
          try {
            return file.getVersionInfoField("FileDescription");
          } catch (e) {}
        }
        break;
      case "macosx":
        if (file instanceof Ci.nsILocalFileMac) {
          try {
            return file.bundleDisplayName;
          } catch (e) {}
        }
        break;
    }

    return file.leafName;
  },

  _chooseClientApp(aTitle, aTypeName, aBrowser) {
    const prefName = getPrefAppForType(aTypeName);
    let fp = Cc["@mozilla.org/filepicker;1"].createInstance(Ci.nsIFilePicker);

    fp.init(window, aTitle, Ci.nsIFilePicker.modeOpen);
    fp.appendFilters(Ci.nsIFilePicker.filterApps);

    fp.open((aResult) => {
      if (aResult == Ci.nsIFilePicker.returnOK) {
        let selectedApp = fp.file;
        if (selectedApp) {
          // XXXben - we need to compare this with the running instance
          //          executable just don't know how to do that via script
          // XXXmano TBD: can probably add this to nsIShellService
          let appName = "";
          switch (AppConstants.platform) {
            case "win":
              appName = AppConstants.MOZ_APP_NAME + ".exe";
              break;
            case "macosx":
              appName = AppConstants.MOZ_MACBUNDLE_NAME;
              break;
            default:
              appName = AppConstants.MOZ_APP_NAME + "-bin";
              break;
          }

          if (fp.file.leafName != appName) {
            Services.prefs.setComplexValue(prefName, Ci.nsILocalFile, selectedApp);
            aBrowser.messageManager.sendAsyncMessage("FeedWriter:SetApplicationLauncherMenuItem",
                                                    { name: this._getFileDisplayName(selectedApp),
                                                      type: "SelectedAppMenuItem" });
          }
        }
      }
    });

  },

  executeClientApp(aSpec, aTitle, aSubtitle, aFeedHandler) {
    // aFeedHandler is either "default", indicating the system default reader, or a pref-name containing
    // an nsILocalFile pointing to the feed handler's executable.

    let clientApp = null;
    if (aFeedHandler == "default") {
      clientApp = Cc["@mozilla.org/browser/shell-service;1"]
                    .getService(Ci.nsIShellService)
                    .defaultFeedReader;
    } else {
      clientApp = Services.prefs.getComplexValue(aFeedHandler, Ci.nsILocalFile);
    }

    // For the benefit of applications that might know how to deal with more
    // URLs than just feeds, send feed: URLs in the following format:
    //
    // http urls: replace scheme with feed, e.g.
    // http://foo.com/index.rdf -> feed://foo.com/index.rdf
    // other urls: prepend feed: scheme, e.g.
    // https://foo.com/index.rdf -> feed:https://foo.com/index.rdf
    let feedURI = NetUtil.newURI(aSpec);
    if (feedURI.schemeIs("http")) {
      feedURI.scheme = "feed";
      aSpec = feedURI.spec;
    } else {
      aSpec = "feed:" + aSpec;
    }

    // Retrieving the shell service might fail on some systems, most
    // notably systems where GNOME is not installed.
    try {
      let ss = Cc["@mozilla.org/browser/shell-service;1"]
                 .getService(Ci.nsIShellService);
      ss.openApplicationWithURI(clientApp, aSpec);
    } catch (e) {
      // If we couldn't use the shell service, fallback to using a
      // nsIProcess instance
      let p = Cc["@mozilla.org/process/util;1"]
                .createInstance(Ci.nsIProcess);
      p.init(clientApp);
      p.run(false, [aSpec], 1);
    }
  },

  // nsISupports

  QueryInterface: XPCOMUtils.generateQI([Ci.nsIObserver,
                                         Ci.nsISupportsWeakReference]),

  init() {
    window.messageManager.addMessageListener("FeedWriter:ChooseClientApp", this);
    window.messageManager.addMessageListener("FeedWriter:GetSubscriptionUI", this);
    window.messageManager.addMessageListener("FeedWriter:SetFeedPrefsAndSubscribe", this);
    window.messageManager.addMessageListener("FeedWriter:ShownFirstRun", this);

    Services.ppmm.addMessageListener("FeedConverter:ExecuteClientApp", this);

    const prefs = Services.prefs;
    prefs.addObserver(PREF_SELECTED_ACTION, this, true);
    prefs.addObserver(PREF_SELECTED_READER, this, true);
    prefs.addObserver(PREF_SELECTED_WEB, this, true);
    prefs.addObserver(PREF_VIDEO_SELECTED_ACTION, this, true);
    prefs.addObserver(PREF_VIDEO_SELECTED_READER, this, true);
    prefs.addObserver(PREF_VIDEO_SELECTED_WEB, this, true);
    prefs.addObserver(PREF_AUDIO_SELECTED_ACTION, this, true);
    prefs.addObserver(PREF_AUDIO_SELECTED_READER, this, true);
    prefs.addObserver(PREF_AUDIO_SELECTED_WEB, this, true);
  },

  uninit() {
    Services.ppmm.removeMessageListener("FeedConverter:ExecuteClientApp", this);

    this._prefChangeCallback = null;
  },

  // nsIObserver
  observe(subject, topic, data) {
    if (topic == "nsPref:changed") {
      LOG(`Pref changed ${data}`)
      if (this._prefChangeCallback) {
        this._prefChangeCallback.disarm();
      }
      // Multiple prefs are set at the same time, debounce to reduce noise
      // This can happen in one feed and we want to message all feed pages
      this._prefChangeCallback = new DeferredTask(() => {
        this._prefChanged(data);
      }, PREF_UPDATE_DELAY);
      this._prefChangeCallback.arm();
    }
  },

  _prefChanged(prefName) {
    // Don't observe for PREF_*SELECTED_APP as user likely just picked one
    // That is also handled by SetApplicationLauncherMenuItem call
    // Rather than the others which happen on subscription
    switch (prefName) {
      case PREF_SELECTED_READER:
      case PREF_SELECTED_WEB:
      case PREF_VIDEO_SELECTED_READER:
      case PREF_VIDEO_SELECTED_WEB:
      case PREF_AUDIO_SELECTED_READER:
      case PREF_AUDIO_SELECTED_WEB:
      case PREF_SELECTED_ACTION:
      case PREF_VIDEO_SELECTED_ACTION:
      case PREF_AUDIO_SELECTED_ACTION:
        const response = {
         default: this._getReaderForType(Ci.nsIFeed.TYPE_FEED),
         [Ci.nsIFeed.TYPE_AUDIO]: this._getReaderForType(Ci.nsIFeed.TYPE_AUDIO),
         [Ci.nsIFeed.TYPE_VIDEO]: this._getReaderForType(Ci.nsIFeed.TYPE_VIDEO)
        };
        Services.mm.broadcastAsyncMessage("FeedWriter:PreferenceUpdated",
                                          response);
        break;
    }
  },

  _initSubscriptionUIResponse(feedType) {
    const wccr = Cc["@mozilla.org/embeddor.implemented/web-content-handler-registrar;1"].
               getService(Ci.nsIWebContentConverterService);
    const handlersRaw = wccr.getContentHandlers(getMimeTypeForFeedType(feedType));
    const handlers = [];
    for (let handler of handlersRaw) {
      LOG(`Handler found: ${handler}`);
      handlers.push({
        name: handler.name,
        uri: handler.uri
      });
    }
    let showFirstRunUI = true;
    // eslint-disable-next-line mozilla/use-default-preference-values
    try {
      showFirstRunUI = Services.prefs.getBoolPref(PREF_SHOW_FIRST_RUN_UI);
    } catch (ex) { }
    const response = { handlers, showFirstRunUI };
    let selectedClientApp;
    const feedTypePref = getPrefAppForType(feedType);
    try {
      selectedClientApp = Services.prefs.getComplexValue(feedTypePref, Ci.nsILocalFile);
    } catch (ex) {
      // Just do nothing, then we won't bother populating
    }

    let defaultClientApp = null;
    try {
      // This can sometimes not exist
      defaultClientApp = Cc["@mozilla.org/browser/shell-service;1"]
                           .getService(Ci.nsIShellService)
                           .defaultFeedReader;
    } catch (ex) {
      // Just do nothing, then we don't bother populating
    }

    if (selectedClientApp && selectedClientApp.exists()) {
      if (defaultClientApp && selectedClientApp.path != defaultClientApp.path) {
        // Only set the default menu item if it differs from the selected one
        response.defaultMenuItem = this._getFileDisplayName(defaultClientApp);
      }
      response.selectedMenuItem = this._getFileDisplayName(selectedClientApp);
    }
    response.reader = this._getReaderForType(feedType);
    return response;
  },

  _setPref(aPrefName, aPrefValue, aIsComplex = false) {
    LOG(`FeedWriter._setPref ${aPrefName}`);
    // Ensure we have a pref that is settable
    if (aPrefName && SETTABLE_PREFS.has(aPrefName)) {
      if (aIsComplex) {
        const supportsString = Cc["@mozilla.org/supports-string;1"].
                             createInstance(Ci.nsISupportsString);
        supportsString.data = aPrefValue;
        Services.prefs.setComplexValue(aPrefName, Ci.nsISupportsString, supportsString);
      } else {
        Services.prefs.setCharPref(aPrefName, aPrefValue);
      }
    } else {
      LOG(`FeedWriter._setPref ${aPrefName} not allowed`);
    }
  },

  _getReaderForType(feedType) {
    let prefs = Services.prefs;
    let handler = "bookmarks";
    let url;
    // eslint-disable-next-line mozilla/use-default-preference-values
    try {
      handler = prefs.getCharPref(getPrefReaderForType(feedType));
    } catch (ex) { }

    if (handler === "web") {
      try {
        url = prefs.getComplexValue(getPrefWebForType(feedType), Ci.nsISupportsString).data;
      } catch (ex) {
        LOG("FeedWriter._setSelectedHandler: invalid or no handler in prefs");
        url = null;
      }
    }
    const alwaysUse = this._getAlwaysUseState(feedType);
    const action = prefs.getCharPref(getPrefActionForType(feedType));
    return { handler, url, alwaysUse, action };
  },

  _getAlwaysUseState(feedType) {
    try {
      return Services.prefs.getCharPref(getPrefActionForType(feedType)) != "ask";
    } catch (ex) { }
    return false;
  },

  receiveMessage(msg) {
    let handler;
    switch (msg.name) {
      case "FeedWriter:GetSubscriptionUI":
        const response = this._initSubscriptionUIResponse(msg.data.feedType);
        msg.target.messageManager
           .sendAsyncMessage("FeedWriter:GetSubscriptionUIResponse",
                            response);
        break;
      case "FeedWriter:ChooseClientApp":
        this._chooseClientApp(msg.data.title, msg.data.feedType, msg.target);
        break;
      case "FeedWriter:ShownFirstRun":
        Services.prefs.setBoolPref(PREF_SHOW_FIRST_RUN_UI, false);
        break;
      case "FeedWriter:SetFeedPrefsAndSubscribe":
        const settings = msg.data;
        if (!settings.action || !VALID_ACTIONS.has(settings.action)) {
          LOG(`Invalid action ${settings.action}`);
          return;
        }
        if (!settings.reader || !VALID_READERS.has(settings.reader)) {
          LOG(`Invalid reader ${settings.reader}`);
          return;
        }
        const actionPref = getPrefActionForType(settings.feedType);
        this._setPref(actionPref, settings.action);
        const readerPref = getPrefReaderForType(settings.feedType);
        this._setPref(readerPref, settings.reader);
        handler = null;

        switch (settings.reader) {
          case "web":
            // This is a web set URI by content using window.registerContentHandler()
            // Lets make sure we know about it before setting it
            const webPref = getPrefWebForType(settings.feedType);
            let wccr = Cc["@mozilla.org/embeddor.implemented/web-content-handler-registrar;1"].
                       getService(Ci.nsIWebContentConverterService);
            // If the user provided an invalid web URL this function won't give us a reference
            handler = wccr.getWebContentHandlerByURI(getMimeTypeForFeedType(settings.feedType), settings.uri);
            if (handler) {
              this._setPref(webPref, settings.uri, true);
              if (settings.useAsDefault) {
                wccr.setAutoHandler(getMimeTypeForFeedType(settings.feedType), handler);
              }
              msg.target.messageManager
                 .sendAsyncMessage("FeedWriter:SetFeedPrefsAndSubscribeResponse",
                                  { redirect: handler.getHandlerURI(settings.feedLocation) });
            } else {
              LOG(`No handler found for web ${settings.feedType} ${settings.uri}`);
            }
            break;
          default:
            const feedService = Cc["@mozilla.org/browser/feeds/result-service;1"].
                                getService(Ci.nsIFeedResultService);

            feedService.addToClientReader(settings.feedLocation,
                                          settings.feedTitle,
                                          settings.feedSubtitle,
                                          settings.feedType,
                                          settings.reader);
        }
        break;
      case "FeedConverter:ExecuteClientApp":
        // Always check feedHandler is from a set array of executable prefs
        if (EXECUTABLE_PREFS.has(msg.data.feedHandler)) {
          this.executeClientApp(msg.data.spec, msg.data.title,
                                msg.data.subtitle, msg.data.feedHandler);
        } else {
          LOG(`FeedConverter:ExecuteClientApp - Will not exec ${msg.data.feedHandler}`);
        }
        break;
    }
  },
};