url = url.QueryInterface(Components.interfaces.nsIRDFLiteral).Value;    else      url = this.resource.Value;    return url;  },  get title()  {    var ds = getSubscriptionsDS(this.server);    var title = ds.GetTarget(this.resource, DC_TITLE, true);    if (title)      title = title.QueryInterface(Components.interfaces.nsIRDFLiteral).Value;    return title;  },  set title (aNewTitle)   {    var ds = getSubscriptionsDS(this.server);    aNewTitle = rdf.GetLiteral(aNewTitle);    var old_title = ds.GetTarget(this.resource, DC_TITLE, true);    if (old_title)        ds.Change(this.resource, DC_TITLE, old_title, aNewTitle);    else        ds.Assert(this.resource, DC_TITLE, aNewTitle, true);  },  get lastModified()  {    var ds = getSubscriptionsDS(this.server);    var lastModified = ds.GetTarget(this.resource, DC_LASTMODIFIED, true);    if (lastModified)      lastModified = lastModified.QueryInterface(Components.interfaces.nsIRDFLiteral).Value;    return lastModified;  },  set lastModified(aLastModified)  {    var ds = getSubscriptionsDS(this.server);    aLastModified = rdf.GetLiteral(aLastModified);    var old_lastmodified = ds.GetTarget(this.resource, DC_LASTMODIFIED, true);    if (old_lastmodified)        ds.Change(this.resource, DC_LASTMODIFIED, old_lastmodified, aLastModified);    else        ds.Assert(this.resource, DC_LASTMODIFIED, aLastModified, true);      // do we need to flush every time this property changes?     ds = ds.QueryInterface(Components.interfaces.nsIRDFRemoteDataSource);        ds.Flush();    },  get quickMode ()  {    var ds = getSubscriptionsDS(this.server);    var quickMode = ds.GetTarget(this.resource, FZ_QUICKMODE, true);    if (quickMode)     {      quickMode = quickMode.QueryInterface(Components.interfaces.nsIRDFLiteral);      quickMode = quickMode.Value;      quickMode = eval(quickMode);    }        return quickMode;  },  set quickMode (aNewQuickMode)   {    var ds = getSubscriptionsDS(this.server);    aNewQuickMode = rdf.GetLiteral(aNewQuickMode);    var old_quickMode = ds.GetTarget(this.resource, FZ_QUICKMODE, true);    if (old_quickMode)      ds.Change(this.resource, FZ_QUICKMODE, old_quickMode, aNewQuickMode);    else      ds.Assert(this.resource, FZ_QUICKMODE, aNewQuickMode, true);  },  get link ()  {    var ds = getSubscriptionsDS(this.server);    var link = ds.GetTarget(this.resource, RSS_LINK, true);    if(link)      link = link.QueryInterface(Components.interfaces.nsIRDFLiteral).Value;    return link;  },  set link (aNewLink)  {    var ds = getSubscriptionsDS(this.server);    aNewLink = rdf.GetLiteral(aNewLink);    var old_link = ds.GetTarget(this.resource, RSS_LINK, true);    if (old_link)      ds.Change(this.resource, RSS_LINK, old_link, aNewLink);    else      ds.Assert(this.resource, RSS_LINK, aNewLink, true);  },  parse: function()   {    // Figures out what description language (RSS, Atom) and version this feed    // is using and calls a language/version-specific feed parser.    debug("parsing feed " + this.url);    if (!this.request.responseText)       return this.onParseError(this);          // create a feed parser which will parse the feed for us    var parser = new FeedParser();    this.itemsToStore = parser.parseFeed(this, this.request.responseText, this.request.responseXML, this.request.channel.URI);      // storeNextItem will iterate through the parsed items, storing each one.    this.itemsToStoreIndex = 0;    this.storeNextItem();  },  invalidateItems: function ()   {    var ds = getItemsDS(this.server);    debug("invalidating items for " + this.url);    var items = ds.GetSources(FZ_FEED, this.resource, true);    var item;      while (items.hasMoreElements())     {      item = items.getNext();      item = item.QueryInterface(Components.interfaces.nsIRDFResource);      debug("invalidating " + item.Value);      var valid = ds.GetTarget(item, FZ_VALID, true);      if (valid)        ds.Unassert(item, FZ_VALID, valid, true);    }  },   removeInvalidItems: function()   {    var ds = getItemsDS(this.server);    debug("removing invalid items for " + this.url);    var items = ds.GetSources(FZ_FEED, this.resource, true);    var item;    while (items.hasMoreElements())     {      item = items.getNext();      item = item.QueryInterface(Components.interfaces.nsIRDFResource);      if (ds.HasAssertion(item, FZ_VALID, RDF_LITERAL_TRUE, true))        continue;      debug("removing " + item.Value);      ds.Unassert(item, FZ_FEED, this.resource, true);      if (ds.hasArcOut(item, FZ_FEED))        debug(item.Value + " is from more than one feed; only the reference to this feed removed");      else        removeAssertions(ds, item);    }  },  createFolder: function()  {       if (!this.folder)       this.server.rootMsgFolder.createSubfolder(this.name, null /* supposed to be a msg window */);        },  // gets the next item from gItemsToStore and forces that item to be stored  // to the folder. If more items are left to be stored, fires a timer for the next one.  // otherwise it triggers a download done notification to the UI  storeNextItem: function()  {    if (!this.itemsToStore ||  !this.itemsToStore.length)    {      this.createFolder();      return this.cleanupParsingState(this);    }    var item = this.itemsToStore[this.itemsToStoreIndex];     item.store();    item.markValid();    // if the listener is tracking progress for storing each item, report it here...    if (item.feed.downloadCallback && item.feed.downloadCallback.onFeedItemStored)      item.feed.downloadCallback.onFeedItemStored(item.feed, this.itemsToStoreIndex, this.itemsToStore.length);     this.itemsToStoreIndex++    // eventually we'll report individual progress here....    if (this.itemsToStoreIndex < this.itemsToStore.length)    {      if (!this.storeItemsTimer)        this.storeItemsTimer = Components.classes["@mozilla.org/timer;1"].createInstance(Components.interfaces.nsITimer);      this.storeItemsTimer.initWithCallback(this, 50, Components.interfaces.nsITimer.TYPE_ONE_SHOT);    }    else    {      // we have just finished downloading one or more feed items into the destination folder,      // if the folder is still listed as having new messages in it, then we should set the biff state on the folder      // so the right RDF UI changes happen in the folder pane to indicate new mail.      if (item.feed.folder.hasNewMessages)        item.feed.folder.biffState = Components.interfaces.nsIMsgFolder.nsMsgBiffState_NewMail;      this.cleanupParsingState(item.feed);       }  },  cleanupParsingState: function(aFeed)   {    // now that we are done parsing the feed, remove the feed from our feed cache    FeedCache.removeFeed(aFeed.url);    aFeed.removeInvalidItems();    // let's be sure to flush any feed item changes back to disk    var ds = getItemsDS(aFeed.server);    ds.QueryInterface(Components.interfaces.nsIRDFRemoteDataSource).Flush(); // flush any changes    if (aFeed.downloadCallback)      aFeed.downloadCallback.downloaded(aFeed, kNewsBlogSuccess);    this.request = null; // force the xml http request to go away. This helps reduce some nasty assertions on shut down.     this.itemsToStore = "";    this.itemsToStoreIndex = 0;    this.storeItemsTimer = null;  },   notify: function(aTimer)   {    this.storeNextItem();  },   QueryInterface: function(aIID)   {    if (aIID.equals(Components.interfaces.nsITimerCallback) || aIID.equals(Components.interfaces.nsISupports))      return this;    Components.returnCode = Components.results.NS_ERROR_NO_INTERFACE;    return null;      }};