The Tor Browser: toolkit/components/feeds/FeedProcessor.js@6474c204b198 (annotated)

toolkit/components/feeds/FeedProcessor.js@6474c204b198 (annotated)

toolkit/components/feeds/FeedProcessor.js

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 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/. */
 function LOG(str) {
   dump("*** " + str + "\n");
 }
 const Ci = Components.interfaces;
 const Cc = Components.classes;
 const Cr = Components.results;
 Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
 const FP_CONTRACTID = "@mozilla.org/feed-processor;1";
 const FP_CLASSID = Components.ID("{26acb1f0-28fc-43bc-867a-a46aabc85dd4}");
 const FP_CLASSNAME = "Feed Processor";
 const FR_CONTRACTID = "@mozilla.org/feed-result;1";
 const FR_CLASSID = Components.ID("{072a5c3d-30c6-4f07-b87f-9f63d51403f2}");
 const FR_CLASSNAME = "Feed Result";
 const FEED_CONTRACTID = "@mozilla.org/feed;1";
 const FEED_CLASSID = Components.ID("{5d0cfa97-69dd-4e5e-ac84-f253162e8f9a}");
 const FEED_CLASSNAME = "Feed";
 const ENTRY_CONTRACTID = "@mozilla.org/feed-entry;1";
 const ENTRY_CLASSID = Components.ID("{8e4444ff-8e99-4bdd-aa7f-fb3c1c77319f}");
 const ENTRY_CLASSNAME = "Feed Entry";
 const TEXTCONSTRUCT_CONTRACTID = "@mozilla.org/feed-textconstruct;1";
 const TEXTCONSTRUCT_CLASSID =
   Components.ID("{b992ddcd-3899-4320-9909-924b3e72c922}");
 const TEXTCONSTRUCT_CLASSNAME = "Feed Text Construct";
 const GENERATOR_CONTRACTID = "@mozilla.org/feed-generator;1";
 const GENERATOR_CLASSID =
   Components.ID("{414af362-9ad8-4296-898e-62247f25a20e}");
 const GENERATOR_CLASSNAME = "Feed Generator";
 const PERSON_CONTRACTID = "@mozilla.org/feed-person;1";
 const PERSON_CLASSID = Components.ID("{95c963b7-20b2-11db-92f6-001422106990}");
 const PERSON_CLASSNAME = "Feed Person";
 const IO_CONTRACTID = "@mozilla.org/network/io-service;1"
 const BAG_CONTRACTID = "@mozilla.org/hash-property-bag;1"
 const ARRAY_CONTRACTID = "@mozilla.org/array;1";
 const SAX_CONTRACTID = "@mozilla.org/saxparser/xmlreader;1";
 const PARSERUTILS_CONTRACTID = "@mozilla.org/parserutils;1";
 var gIoService = null;
 const XMLNS = "http://www.w3.org/XML/1998/namespace";
 const RSS090NS = "http://my.netscape.com/rdf/simple/0.9/";
 /***** Some general utils *****/
 function strToURI(link, base) {
   var base = base || null;
   if (!gIoService)
     gIoService = Cc[IO_CONTRACTID].getService(Ci.nsIIOService);
   try {
     return gIoService.newURI(link, null, base);
   }
   catch(e) {
     return null;
   }
 }
 function isArray(a) {
   return isObject(a) && a.constructor == Array;
 }
 function isObject(a) {
   return (a && typeof a == "object") || isFunction(a);
 }
 function isFunction(a) {
   return typeof a == "function";
 }
 function isIID(a, iid) {
   var rv = false;
   try {
     a.QueryInterface(iid);
     rv = true;
   }
   catch(e) {
   }
   return rv;
 }
 function isIArray(a) {
   return isIID(a, Ci.nsIArray);
 }
 function isIFeedContainer(a) {
   return isIID(a, Ci.nsIFeedContainer);
 }
 function stripTags(someHTML) {
   return someHTML.replace(/<[^>]+>/g,"");
 }
 /**
  * Searches through an array of links and returns a JS array
  * of matching property bags.
  */
 const IANA_URI = "http://www.iana.org/assignments/relation/";
 function findAtomLinks(rel, links) {
   var rvLinks = [];
   for (var i = 0; i < links.length; ++i) {
     var linkElement = links.queryElementAt(i, Ci.nsIPropertyBag2);
     // atom:link MUST have @href
     if (bagHasKey(linkElement, "href")) {
       var relAttribute = null;
       if (bagHasKey(linkElement, "rel"))
         relAttribute = linkElement.getPropertyAsAString("rel")
       if ((!relAttribute && rel == "alternate") || relAttribute == rel) {
         rvLinks.push(linkElement);
         continue;
       }
       // catch relations specified by IANA URI
       if (relAttribute == IANA_URI + rel) {
         rvLinks.push(linkElement);
       }
     }
   }
   return rvLinks;
 }
 function xmlEscape(s) {
   s = s.replace(/&/g, "&amp;");
   s = s.replace(/>/g, "&gt;");
   s = s.replace(/</g, "&lt;");
   s = s.replace(/"/g, "&quot;");
   s = s.replace(/'/g, "&apos;");
   return s;
 }
 function arrayContains(array, element) {
   for (var i = 0; i < array.length; ++i) {
     if (array[i] == element) {
       return true;
     }
   }
   return false;
 }
 // XXX add hasKey to nsIPropertyBag
 function bagHasKey(bag, key) {
   try {
     bag.getProperty(key);
     return true;
   }
   catch (e) {
     return false;
   }
 }
 function makePropGetter(key) {
   return function FeedPropGetter(bag) {
     try {
       return value = bag.getProperty(key);
     }
     catch(e) {
     }
     return null;
   }
 }
 const RDF_NS = "http://www.w3.org/1999/02/22-rdf-syntax-ns#";
 // namespace map
 var gNamespaces = {
   "http://webns.net/mvcb/":"admin",
   "http://backend.userland.com/rss":"",
   "http://blogs.law.harvard.edu/tech/rss":"",
   "http://www.w3.org/2005/Atom":"atom",
   "http://purl.org/atom/ns#":"atom03",
   "http://purl.org/rss/1.0/modules/content/":"content",
   "http://purl.org/dc/elements/1.1/":"dc",
   "http://purl.org/dc/terms/":"dcterms",
   "http://www.w3.org/1999/02/22-rdf-syntax-ns#":"rdf",
   "http://purl.org/rss/1.0/":"rss1",
   "http://my.netscape.com/rdf/simple/0.9/":"rss1",
   "http://wellformedweb.org/CommentAPI/":"wfw",
   "http://purl.org/rss/1.0/modules/wiki/":"wiki",
   "http://www.w3.org/XML/1998/namespace":"xml",
   "http://search.yahoo.com/mrss/":"media",
   "http://search.yahoo.com/mrss":"media"
 }
 // We allow a very small set of namespaces in XHTML content,
 // for attributes only
 var gAllowedXHTMLNamespaces = {
   "http://www.w3.org/XML/1998/namespace":"xml",
   // if someone ns qualifies XHTML, we have to prefix it to avoid an
   // attribute collision.
   "http://www.w3.org/1999/xhtml":"xhtml"
 }
 function FeedResult() {}
 FeedResult.prototype = {
   bozo: false,
   doc: null,
   version: null,
   headers: null,
   uri: null,
   stylesheet: null,
   registerExtensionPrefix: function FR_registerExtensionPrefix(ns, prefix) {
     throw Cr.NS_ERROR_NOT_IMPLEMENTED;
   },
   // XPCOM stuff
   classID: FR_CLASSID,
   QueryInterface: XPCOMUtils.generateQI([Ci.nsIFeedResult])
 }
 function Feed() {
   this.subtitle = null;
   this.title = null;
   this.items = Cc[ARRAY_CONTRACTID].createInstance(Ci.nsIMutableArray);
   this.link = null;
   this.id = null;
   this.generator = null;
   this.authors = Cc[ARRAY_CONTRACTID].createInstance(Ci.nsIMutableArray);
   this.contributors = Cc[ARRAY_CONTRACTID].createInstance(Ci.nsIMutableArray);
   this.baseURI = null;
   this.enclosureCount = 0;
   this.type = Ci.nsIFeed.TYPE_FEED;
 }
 Feed.prototype = {
   searchLists: {
     title: ["title", "rss1:title", "atom03:title", "atom:title"],
     subtitle: ["description","dc:description","rss1:description",
                "atom03:tagline","atom:subtitle"],
     items: ["items","atom03_entries","entries"],
     id: ["atom:id","rdf:about"],
     generator: ["generator"],
     authors : ["authors"],
     contributors: ["contributors"],
     title: ["title","rss1:title", "atom03:title","atom:title"],
     link:  [["link",strToURI],["rss1:link",strToURI]],
     categories: ["categories", "dc:subject"],
     rights: ["atom03:rights","atom:rights"],
     cloud: ["cloud"],
     image: ["image", "rss1:image", "atom:logo"],
     textInput: ["textInput", "rss1:textinput"],
     skipDays: ["skipDays"],
     skipHours: ["skipHours"],
     updated: ["pubDate", "lastBuildDate", "atom03:modified", "dc:date",
               "dcterms:modified", "atom:updated"]
   },
   normalize: function Feed_normalize() {
     fieldsToObj(this, this.searchLists);
     if (this.skipDays)
       this.skipDays = this.skipDays.getProperty("days");
     if (this.skipHours)
       this.skipHours = this.skipHours.getProperty("hours");
     if (this.updated)
       this.updated = dateParse(this.updated);
     // Assign Atom link if needed
     if (bagHasKey(this.fields, "links"))
       this._atomLinksToURI();
     this._calcEnclosureCountAndFeedType();
     // Resolve relative image links
     if (this.image && bagHasKey(this.image, "url"))
       this._resolveImageLink();
     this._resetBagMembersToRawText([this.searchLists.subtitle,
                                     this.searchLists.title]);
   },
   _calcEnclosureCountAndFeedType: function Feed_calcEnclosureCountAndFeedType() {
     var entries_with_enclosures = 0;
     var audio_count = 0;
     var image_count = 0;
     var video_count = 0;
     var other_count = 0;
     for (var i = 0; i < this.items.length; ++i) {
       var entry = this.items.queryElementAt(i, Ci.nsIFeedEntry);
       entry.QueryInterface(Ci.nsIFeedContainer);
       if (entry.enclosures && entry.enclosures.length > 0) {
         ++entries_with_enclosures;
         for (var e = 0; e < entry.enclosures.length; ++e) {
           var enc = entry.enclosures.queryElementAt(e, Ci.nsIWritablePropertyBag2);
           if (enc.hasKey("type")) {
             var enctype = enc.get("type");
             if (/^audio/.test(enctype)) {
               ++audio_count;
             } else if (/^image/.test(enctype)) {
               ++image_count;
             } else if (/^video/.test(enctype)) {
               ++video_count;
             } else {
               ++other_count;
             }
           } else {
             ++other_count;
           }
         }
       }
     }
     var feedtype = Ci.nsIFeed.TYPE_FEED;
     // For a feed to be marked as TYPE_VIDEO, TYPE_AUDIO and TYPE_IMAGE,
     // we enforce two things:
     //
     //    1. all entries must have at least one enclosure
     //    2. all enclosures must be video for TYPE_VIDEO, audio for TYPE_AUDIO or image
     //       for TYPE_IMAGE
     //
     // Otherwise it's a TYPE_FEED.
     if (entries_with_enclosures == this.items.length && other_count == 0) {
       if (audio_count > 0 && !video_count && !image_count) {
         feedtype = Ci.nsIFeed.TYPE_AUDIO;
       } else if (image_count > 0 && !audio_count && !video_count) {
         feedtype = Ci.nsIFeed.TYPE_IMAGE;
       } else if (video_count > 0 && !audio_count && !image_count) {
         feedtype = Ci.nsIFeed.TYPE_VIDEO;
       }
     }
     this.type = feedtype;
     this.enclosureCount = other_count + video_count + audio_count + image_count;
   },
   _atomLinksToURI: function Feed_linkToURI() {
     var links = this.fields.getPropertyAsInterface("links", Ci.nsIArray);
     var alternates = findAtomLinks("alternate", links);
     if (alternates.length > 0) {
       var href = alternates[0].getPropertyAsAString("href");
       var base;
       if (bagHasKey(alternates[0], "xml:base"))
         base = alternates[0].getPropertyAsAString("xml:base");
       this.link = this._resolveURI(href, base);
     }
   },
   _resolveImageLink: function Feed_resolveImageLink() {
     var base;
     if (bagHasKey(this.image, "xml:base"))
       base = this.image.getPropertyAsAString("xml:base");
     var url = this._resolveURI(this.image.getPropertyAsAString("url"), base);
     if (url)
       this.image.setPropertyAsAString("url", url.spec);
   },
   _resolveURI: function Feed_resolveURI(linkSpec, baseSpec) {
     var uri = null;
     try {
       var base = baseSpec ? strToURI(baseSpec, this.baseURI) : this.baseURI;
       uri = strToURI(linkSpec, base);
     }
     catch(e) {
       LOG(e);
     }
     return uri;
   },
   // reset the bag to raw contents, not text constructs
   _resetBagMembersToRawText: function Feed_resetBagMembers(fieldLists) {
     for (var i=0; i<fieldLists.length; i++) {
       for (var j=0; j<fieldLists[i].length; j++) {
         if (bagHasKey(this.fields, fieldLists[i][j])) {
           var textConstruct = this.fields.getProperty(fieldLists[i][j]);
           this.fields.setPropertyAsAString(fieldLists[i][j],
                                            textConstruct.text);
         }
       }
     }
   },
   // XPCOM stuff
   classID: FEED_CLASSID,
   QueryInterface: XPCOMUtils.generateQI([Ci.nsIFeed, Ci.nsIFeedContainer])
 }
 function Entry() {
   this.summary = null;
   this.content = null;
   this.title = null;
   this.fields = Cc["@mozilla.org/hash-property-bag;1"].
     createInstance(Ci.nsIWritablePropertyBag2);
   this.link = null;
   this.id = null;
   this.baseURI = null;
   this.updated = null;
   this.published = null;
   this.authors = Cc[ARRAY_CONTRACTID].createInstance(Ci.nsIMutableArray);
   this.contributors = Cc[ARRAY_CONTRACTID].createInstance(Ci.nsIMutableArray);
 }
 Entry.prototype = {
   fields: null,
   enclosures: null,
   mediaContent: null,
   searchLists: {
     title: ["title", "rss1:title", "atom03:title", "atom:title"],
     link: [["link",strToURI],["rss1:link",strToURI]],
     id: [["guid", makePropGetter("guid")], "rdf:about",
          "atom03:id", "atom:id"],
     authors : ["authors"],
     contributors: ["contributors"],
     summary: ["description", "rss1:description", "dc:description",
               "atom03:summary", "atom:summary"],
     content: ["content:encoded","atom03:content","atom:content"],
     rights: ["atom03:rights","atom:rights"],
     published: ["pubDate", "atom03:issued", "dcterms:issued", "atom:published"],
     updated: ["pubDate", "atom03:modified", "dc:date", "dcterms:modified",
               "atom:updated"]
   },
   normalize: function Entry_normalize() {
     fieldsToObj(this, this.searchLists);
     // Assign Atom link if needed
     if (bagHasKey(this.fields, "links"))
       this._atomLinksToURI();
     // Populate enclosures array
     this._populateEnclosures();
     // The link might be a guid w/ permalink=true
     if (!this.link && bagHasKey(this.fields, "guid")) {
       var guid = this.fields.getProperty("guid");
       var isPermaLink = true;
       if (bagHasKey(guid, "isPermaLink"))
         isPermaLink = guid.getProperty("isPermaLink").toLowerCase() != "false";
       if (guid && isPermaLink)
         this.link = strToURI(guid.getProperty("guid"));
     }
     if (this.updated)
       this.updated = dateParse(this.updated);
     if (this.published)
       this.published = dateParse(this.published);
     this._resetBagMembersToRawText([this.searchLists.content,
                                     this.searchLists.summary,
                                     this.searchLists.title]);
   },
   _populateEnclosures: function Entry_populateEnclosures() {
     if (bagHasKey(this.fields, "links"))
       this._atomLinksToEnclosures();
     // Add RSS2 enclosure to enclosures
     if (bagHasKey(this.fields, "enclosure"))
       this._enclosureToEnclosures();
     // Add media:content to enclosures
     if (bagHasKey(this.fields, "mediacontent"))
       this._mediacontentToEnclosures();
     // Add media:content in media:group to enclosures
     if (bagHasKey(this.fields, "mediagroup"))
       this._mediagroupToEnclosures();
   },
   __enclosure_map: null,
   _addToEnclosures: function Entry_addToEnclosures(new_enc) {
     // items we add to the enclosures array get displayed in the FeedWriter and
     // they must have non-empty urls.
     if (!bagHasKey(new_enc, "url") || new_enc.getPropertyAsAString("url") == "")
       return;
     if (this.__enclosure_map == null)
       this.__enclosure_map = {};
     var previous_enc = this.__enclosure_map[new_enc.getPropertyAsAString("url")];
     if (previous_enc != undefined) {
       previous_enc.QueryInterface(Ci.nsIWritablePropertyBag2);
       if (!bagHasKey(previous_enc, "type") && bagHasKey(new_enc, "type"))
         previous_enc.setPropertyAsAString("type", new_enc.getPropertyAsAString("type"));
       if (!bagHasKey(previous_enc, "length") && bagHasKey(new_enc, "length"))
         previous_enc.setPropertyAsAString("length", new_enc.getPropertyAsAString("length"));
       return;
     }
     if (this.enclosures == null) {
       this.enclosures = Cc[ARRAY_CONTRACTID].createInstance(Ci.nsIMutableArray);
       this.enclosures.QueryInterface(Ci.nsIMutableArray);
     }
     this.enclosures.appendElement(new_enc, false);
     this.__enclosure_map[new_enc.getPropertyAsAString("url")] = new_enc;
   },
   _atomLinksToEnclosures: function Entry_linkToEnclosure() {
     var links = this.fields.getPropertyAsInterface("links", Ci.nsIArray);
     var enc_links = findAtomLinks("enclosure", links);
     if (enc_links.length == 0)
       return;
     for (var i = 0; i < enc_links.length; ++i) {
       var link = enc_links[i];
       // an enclosure must have an href
       if (!(link.getProperty("href")))
         return;
       var enc = Cc[BAG_CONTRACTID].createInstance(Ci.nsIWritablePropertyBag2);
       // copy Atom bits over to equivalent enclosure bits
       enc.setPropertyAsAString("url", link.getPropertyAsAString("href"));
       if (bagHasKey(link, "type"))
         enc.setPropertyAsAString("type", link.getPropertyAsAString("type"));
       if (bagHasKey(link, "length"))
         enc.setPropertyAsAString("length", link.getPropertyAsAString("length"));
       this._addToEnclosures(enc);
     }
   },
   _enclosureToEnclosures: function Entry_enclosureToEnclosures() {
     var enc = this.fields.getPropertyAsInterface("enclosure", Ci.nsIPropertyBag2);
     if (!(enc.getProperty("url")))
       return;
     this._addToEnclosures(enc);
   },
   _mediacontentToEnclosures: function Entry_mediacontentToEnclosures() {
     var mediacontent = this.fields.getPropertyAsInterface("mediacontent", Ci.nsIArray);
     for (var i = 0; i < mediacontent.length; ++i) {
       var contentElement = mediacontent.queryElementAt(i, Ci.nsIWritablePropertyBag2);
       // media:content don't require url, but if it's not there, we should
       // skip it.
       if (!bagHasKey(contentElement, "url"))
         continue;
       var enc = Cc[BAG_CONTRACTID].createInstance(Ci.nsIWritablePropertyBag2);
       // copy media:content bits over to equivalent enclosure bits
       enc.setPropertyAsAString("url", contentElement.getPropertyAsAString("url"));
       if (bagHasKey(contentElement, "type")) {
         enc.setPropertyAsAString("type", contentElement.getPropertyAsAString("type"));
       }
       if (bagHasKey(contentElement, "fileSize")) {
         enc.setPropertyAsAString("length", contentElement.getPropertyAsAString("fileSize"));
       }
       this._addToEnclosures(enc);
     }
   },
   _mediagroupToEnclosures: function Entry_mediagroupToEnclosures() {
     var group = this.fields.getPropertyAsInterface("mediagroup", Ci.nsIPropertyBag2);
     var content = group.getPropertyAsInterface("mediacontent", Ci.nsIArray);
     for (var i = 0; i < content.length; ++i) {
       var contentElement = content.queryElementAt(i, Ci.nsIWritablePropertyBag2);
       // media:content don't require url, but if it's not there, we should
       // skip it.
       if (!bagHasKey(contentElement, "url"))
         continue;
       var enc = Cc[BAG_CONTRACTID].createInstance(Ci.nsIWritablePropertyBag2);
       // copy media:content bits over to equivalent enclosure bits
       enc.setPropertyAsAString("url", contentElement.getPropertyAsAString("url"));
       if (bagHasKey(contentElement, "type")) {
         enc.setPropertyAsAString("type", contentElement.getPropertyAsAString("type"));
       }
       if (bagHasKey(contentElement, "fileSize")) {
         enc.setPropertyAsAString("length", contentElement.getPropertyAsAString("fileSize"));
       }
       this._addToEnclosures(enc);
     }
   },
   // XPCOM stuff
   classID: ENTRY_CLASSID,
   QueryInterface: XPCOMUtils.generateQI(
     [Ci.nsIFeedEntry, Ci.nsIFeedContainer]
   )
 }
 Entry.prototype._atomLinksToURI = Feed.prototype._atomLinksToURI;
 Entry.prototype._resolveURI = Feed.prototype._resolveURI;
 Entry.prototype._resetBagMembersToRawText =
    Feed.prototype._resetBagMembersToRawText;
 // TextConstruct represents and element that could contain (X)HTML
 function TextConstruct() {
   this.lang = null;
   this.base = null;
   this.type = "text";
   this.text = null;
   this.parserUtils = Cc[PARSERUTILS_CONTRACTID].getService(Ci.nsIParserUtils);
 }
 TextConstruct.prototype = {
   plainText: function TC_plainText() {
     if (this.type != "text") {
       return this.parserUtils.convertToPlainText(stripTags(this.text),
         Ci.nsIDocumentEncoder.OutputSelectionOnly |
         Ci.nsIDocumentEncoder.OutputAbsoluteLinks,
 );
     }
     return this.text;
   },
   createDocumentFragment: function TC_createDocumentFragment(element) {
     if (this.type == "text") {
       var doc = element.ownerDocument;
       var docFragment = doc.createDocumentFragment();
       var node = doc.createTextNode(this.text);
       docFragment.appendChild(node);
       return docFragment;
     }
     var isXML;
     if (this.type == "xhtml")
       isXML = true
     else if (this.type == "html")
       isXML = false;
     else
       return null;
     return this.parserUtils.parseFragment(this.text, 0, isXML,
                                           this.base, element);
   },
   // XPCOM stuff
   classID: TEXTCONSTRUCT_CLASSID,
   QueryInterface: XPCOMUtils.generateQI([Ci.nsIFeedTextConstruct])
 }
 // Generator represents the software that produced the feed
 function Generator() {
   this.lang = null;
   this.agent = null;
   this.version = null;
   this.uri = null;
   // nsIFeedElementBase
   this._attributes = null;
   this.baseURI = null;
 }
 Generator.prototype = {
   get attributes() {
     return this._attributes;
   },
   set attributes(value) {
     this._attributes = value;
     this.version = this._attributes.getValueFromName("","version");
     var uriAttribute = this._attributes.getValueFromName("","uri") ||
                        this._attributes.getValueFromName("","url");
     this.uri = strToURI(uriAttribute, this.baseURI);
     // RSS1
     uriAttribute = this._attributes.getValueFromName(RDF_NS,"resource");
     if (uriAttribute) {
       this.agent = uriAttribute;
       this.uri = strToURI(uriAttribute, this.baseURI);
     }
   },
   // XPCOM stuff
   classID: GENERATOR_CLASSID,
   QueryInterface: XPCOMUtils.generateQI(
     [Ci.nsIFeedGenerator, Ci.nsIFeedElementBase]
   )
 }
 function Person() {
   this.name = null;
   this.uri = null;
   this.email = null;
   // nsIFeedElementBase
   this.attributes = null;
   this.baseURI = null;
 }
 Person.prototype = {
   // XPCOM stuff
   classID: PERSON_CLASSID,
   QueryInterface: XPCOMUtils.generateQI(
     [Ci.nsIFeedPerson, Ci.nsIFeedElementBase]
   )
 }
 /**
  * Map a list of fields into properties on a container.
  *
  * @param container An nsIFeedContainer
  * @param fields A list of fields to search for. List members can
  *               be a list, in which case the second member is
  *               transformation function (like parseInt).
  */
 function fieldsToObj(container, fields) {
   var props,prop,field,searchList;
   for (var key in fields) {
     searchList = fields[key];
     for (var i=0; i < searchList.length; ++i) {
       props = searchList[i];
       prop = null;
       field = isArray(props) ? props[0] : props;
       try {
         prop = container.fields.getProperty(field);
       }
       catch(e) {
       }
       if (prop) {
         prop = isArray(props) ? props[1](prop) : prop;
         container[key] = prop;
       }
     }
   }
 }
 /**
  * Lower cases an element's localName property
  * @param   element A DOM element.
  *
  * @returns The lower case localName property of the specified element
  */
 function LC(element) {
   return element.localName.toLowerCase();
 }
 // TODO move these post-processor functions
 // create a generator element
 function atomGenerator(s, generator) {
   generator.QueryInterface(Ci.nsIFeedGenerator);
   generator.agent = s.trim();
   return generator;
 }
 // post-process atom:logo to create an RSS2-like structure
 function atomLogo(s, logo) {
   logo.setPropertyAsAString("url", s.trim());
 }
 // post-process an RSS category, map it to the Atom fields.
 function rssCatTerm(s, cat) {
   // add slash handling?
   cat.setPropertyAsAString("term", s.trim());
   return cat;
 }
 // post-process a GUID
 function rssGuid(s, guid) {
   guid.setPropertyAsAString("guid", s.trim());
   return guid;
 }
 // post-process an RSS author element
 //
 // It can contain a field like this:
 //
 //  <author>lawyer@boyer.net (Lawyer Boyer)</author>
 //
 // or, delightfully, a field like this:
 //
 //  <dc:creator>Simon St.Laurent (mailto:simonstl@simonstl.com)</dc:creator>
 //
 // We want to split this up and assign it to corresponding Atom
 // fields.
 //
 function rssAuthor(s,author) {
   author.QueryInterface(Ci.nsIFeedPerson);
   // check for RSS2 string format
   var chars = s.trim();
   var matches = chars.match(/(.*)\((.*)\)/);
   var emailCheck =
     /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
   if (matches) {
     var match1 = matches[1].trim();
     var match2 = matches[2].trim();
     if (match2.indexOf("mailto:") == 0)
       match2 = match2.substring(7);
     if (emailCheck.test(match1)) {
       author.email = match1;
       author.name = match2;
     }
     else if (emailCheck.test(match2)) {
       author.email = match2;
       author.name = match1;
     }
     else {
       // put it back together
       author.name = match1 + " (" + match2 + ")";
     }
   }
   else {
     author.name = chars;
     if (chars.indexOf('@'))
       author.email = chars;
   }
   return author;
 }
 //
 // skipHours and skipDays map to arrays, so we need to change the
 // string to an nsISupports in order to stick it in there.
 //
 function rssArrayElement(s) {
   var str = Cc["@mozilla.org/supports-string;1"].
               createInstance(Ci.nsISupportsString);
   str.data = s;
   str.QueryInterface(Ci.nsISupportsString);
   return str;
 }
 /**
  * Tries parsing a string through the JavaScript Date object.
  * @param aDateString
  *        A string that is supposedly an RFC822 or RFC3339 date.
  * @return A Date.toUTCString, or null if the string can't be parsed.
  */
 function dateParse(aDateString) {
   let dateString = aDateString.trim();
   // Without bug 682781 fixed, JS won't parse an RFC822 date with a Z for the
   // timezone, so convert to -00:00 which works for any date format.
   dateString = dateString.replace(/z$/i, "-00:00");
   let date = new Date(dateString);
   if (!isNaN(date)) {
     return date.toUTCString();
   }
   return null;
 }
 const XHTML_NS = "http://www.w3.org/1999/xhtml";
 // The XHTMLHandler handles inline XHTML found in things like atom:summary
 function XHTMLHandler(processor, isAtom) {
   this._buf = "";
   this._processor = processor;
   this._depth = 0;
   this._isAtom = isAtom;
   // a stack of lists tracking in-scope namespaces
   this._inScopeNS = [];
 }
 // The fidelity can be improved here, to allow handling of stuff like
 // SVG and MathML. XXX
 XHTMLHandler.prototype = {
    // look back up at the declared namespaces
    // we always use the same prefixes for our safe stuff
   _isInScope: function XH__isInScope(ns) {
     for (var i in this._inScopeNS) {
       for (var uri in this._inScopeNS[i]) {
         if (this._inScopeNS[i][uri] == ns)
           return true;
       }
     }
     return false;
   },
   startDocument: function XH_startDocument() {
   },
   endDocument: function XH_endDocument() {
   },
   startElement: function XH_startElement(uri, localName, qName, attributes) {
     ++this._depth;
     this._inScopeNS.push([]);
     // RFC4287 requires XHTML to be wrapped in a div that is *not* part of
     // the content. This prevents people from screwing up namespaces, but
     // we need to skip it here.
     if (this._isAtom && this._depth == 1 && localName == "div")
       return;
     // If it's an XHTML element, record it. Otherwise, it's ignored.
     if (uri == XHTML_NS) {
       this._buf += "<" + localName;
       var uri;
       for (var i=0; i < attributes.length; ++i) {
         uri = attributes.getURI(i);
         // XHTML attributes aren't in a namespace
         if (uri == "") {
           this._buf += (" " + attributes.getLocalName(i) + "='" +
                         xmlEscape(attributes.getValue(i)) + "'");
         } else {
           // write a small set of allowed attribute namespaces
           var prefix = gAllowedXHTMLNamespaces[uri];
           if (prefix != null) {
             // The attribute value we'll attempt to write
             var attributeValue = xmlEscape(attributes.getValue(i));
             // it's an allowed attribute NS.
             // write the attribute
             this._buf += (" " + prefix + ":" +
                           attributes.getLocalName(i) +
                           "='" + attributeValue + "'");
             // write an xmlns declaration if necessary
             if (prefix != "xml" && !this._isInScope(uri)) {
               this._inScopeNS[this._inScopeNS.length - 1].push(uri);
               this._buf += " xmlns:" + prefix + "='" + uri + "'";
             }
           }
         }
       }
       this._buf += ">";
     }
   },
   endElement: function XH_endElement(uri, localName, qName) {
     --this._depth;
     this._inScopeNS.pop();
     // We need to skip outer divs in Atom. See comment in startElement.
     if (this._isAtom && this._depth == 0 && localName == "div")
       return;
     // When we peek too far, go back to the main processor
     if (this._depth < 0) {
       this._processor.returnFromXHTMLHandler(this._buf.trim(),
                                              uri, localName, qName);
       return;
     }
     // If it's an XHTML element, record it. Otherwise, it's ignored.
     if (uri == XHTML_NS) {
       this._buf += "</" + localName + ">";
     }
   },
   characters: function XH_characters(data) {
     this._buf += xmlEscape(data);
   },
   startPrefixMapping: function XH_startPrefixMapping(prefix, uri) {
   },
   endPrefixMapping: function FP_endPrefixMapping(prefix) {
   },
   processingInstruction: function XH_processingInstruction() {
   },
 }
 /**
  * The ExtensionHandler deals with elements we haven't explicitly
  * added to our transition table in the FeedProcessor.
  */
 function ExtensionHandler(processor) {
   this._buf = "";
   this._depth = 0;
   this._hasChildElements = false;
   // The FeedProcessor
   this._processor = processor;
   // Fields of the outermost extension element.
   this._localName = null;
   this._uri = null;
   this._qName = null;
   this._attrs = null;
 }
 ExtensionHandler.prototype = {
   startDocument: function EH_startDocument() {
   },
   endDocument: function EH_endDocument() {
   },
   startElement: function EH_startElement(uri, localName, qName, attrs) {
     ++this._depth;
     var prefix = gNamespaces[uri] ? gNamespaces[uri] + ":" : "";
     var key =  prefix + localName;
     if (this._depth == 1) {
       this._uri = uri;
       this._localName = localName;
       this._qName = qName;
       this._attrs = attrs;
     }
     // if we descend into another element, we won't send text
     this._hasChildElements = (this._depth > 1);
   },
   endElement: function EH_endElement(uri, localName, qName) {
     --this._depth;
     if (this._depth == 0) {
       var text = this._hasChildElements ? null : this._buf.trim();
       this._processor.returnFromExtHandler(this._uri, this._localName,
                                            text, this._attrs);
     }
   },
   characters: function EH_characters(data) {
     if (!this._hasChildElements)
       this._buf += data;
   },
   startPrefixMapping: function EH_startPrefixMapping() {
   },
   endPrefixMapping: function EH_endPrefixMapping() {
   },
   processingInstruction: function EH_processingInstruction() {
   },
 };
 /**
  * ElementInfo is a simple container object that describes
  * some characteristics of a feed element. For example, it
  * says whether an element can be expected to appear more
  * than once inside a given entry or feed.
  */
 function ElementInfo(fieldName, containerClass, closeFunc, isArray) {
   this.fieldName = fieldName;
   this.containerClass = containerClass;
   this.closeFunc = closeFunc;
   this.isArray = isArray;
   this.isWrapper = false;
 }
 /**
  * FeedElementInfo represents a feed element, usually the root.
  */
 function FeedElementInfo(fieldName, feedVersion) {
   this.isWrapper = false;
   this.fieldName = fieldName;
   this.feedVersion = feedVersion;
 }
 /**
  * Some feed formats include vestigial wrapper elements that we don't
  * want to include in our object model, but we do need to keep track
  * of during parsing.
  */
 function WrapperElementInfo(fieldName) {
   this.isWrapper = true;
   this.fieldName = fieldName;
 }
 /***** The Processor *****/
 function FeedProcessor() {
   this._reader = Cc[SAX_CONTRACTID].createInstance(Ci.nsISAXXMLReader);
   this._buf =  "";
   this._feed = Cc[BAG_CONTRACTID].createInstance(Ci.nsIWritablePropertyBag2);
   this._handlerStack = [];
   this._xmlBaseStack = []; // sparse array keyed to nesting depth
   this._depth = 0;
   this._state = "START";
   this._result = null;
   this._extensionHandler = null;
   this._xhtmlHandler = null;
   this._haveSentResult = false;
   // The nsIFeedResultListener waiting for the parse results
   this.listener = null;
   // These elements can contain (X)HTML or plain text.
   // We keep a table here that contains their default treatment
   this._textConstructs = {"atom:title":"text",
                           "atom:summary":"text",
                           "atom:rights":"text",
                           "atom:content":"text",
                           "atom:subtitle":"text",
                           "description":"html",
                           "rss1:description":"html",
                           "dc:description":"html",
                           "content:encoded":"html",
                           "title":"text",
                           "rss1:title":"text",
                           "atom03:title":"text",
                           "atom03:tagline":"text",
                           "atom03:summary":"text",
                           "atom03:content":"text"};
   this._stack = [];
   this._trans = {
     "START": {
       //If we hit a root RSS element, treat as RSS2.
       "rss": new FeedElementInfo("RSS2", "rss2"),
       // If we hit an RDF element, if could be RSS1, but we can't
       // verify that until we hit a rss1:channel element.
       "rdf:RDF": new WrapperElementInfo("RDF"),
       // If we hit a Atom 1.0 element, treat as Atom 1.0.
       "atom:feed": new FeedElementInfo("Atom", "atom"),
       // Treat as Atom 0.3
       "atom03:feed": new FeedElementInfo("Atom03", "atom03"),
     },
     /********* RSS2 **********/
     "IN_RSS2": {
       "channel": new WrapperElementInfo("channel")
     },
     "IN_CHANNEL": {
       "item": new ElementInfo("items", Cc[ENTRY_CONTRACTID], null, true),
       "managingEditor": new ElementInfo("authors", Cc[PERSON_CONTRACTID],
                                         rssAuthor, true),
       "dc:creator": new ElementInfo("authors", Cc[PERSON_CONTRACTID],
                                     rssAuthor, true),
       "dc:author": new ElementInfo("authors", Cc[PERSON_CONTRACTID],
                                    rssAuthor, true),
       "dc:contributor": new ElementInfo("contributors", Cc[PERSON_CONTRACTID],
                                          rssAuthor, true),
       "category": new ElementInfo("categories", null, rssCatTerm, true),
       "cloud": new ElementInfo("cloud", null, null, false),
       "image": new ElementInfo("image", null, null, false),
       "textInput": new ElementInfo("textInput", null, null, false),
       "skipDays": new ElementInfo("skipDays", null, null, false),
       "skipHours": new ElementInfo("skipHours", null, null, false),
       "generator": new ElementInfo("generator", Cc[GENERATOR_CONTRACTID],
                                    atomGenerator, false),
     },
     "IN_ITEMS": {
       "author": new ElementInfo("authors", Cc[PERSON_CONTRACTID],
                                 rssAuthor, true),
       "dc:creator": new ElementInfo("authors", Cc[PERSON_CONTRACTID],
                                     rssAuthor, true),
       "dc:author": new ElementInfo("authors", Cc[PERSON_CONTRACTID],
                                    rssAuthor, true),
       "dc:contributor": new ElementInfo("contributors", Cc[PERSON_CONTRACTID],
                                          rssAuthor, true),
       "category": new ElementInfo("categories", null, rssCatTerm, true),
       "enclosure": new ElementInfo("enclosure", null, null, false),
       "media:content": new ElementInfo("mediacontent", null, null, true),
       "media:group": new ElementInfo("mediagroup", null, null, false),
       "guid": new ElementInfo("guid", null, rssGuid, false)
     },
     "IN_SKIPDAYS": {
       "day": new ElementInfo("days", null, rssArrayElement, true)
     },
     "IN_SKIPHOURS":{
       "hour": new ElementInfo("hours", null, rssArrayElement, true)
     },
     "IN_MEDIAGROUP": {
       "media:content": new ElementInfo("mediacontent", null, null, true)
     },
     /********* RSS1 **********/
     "IN_RDF": {
       // If we hit a rss1:channel, we can verify that we have RSS1
       "rss1:channel": new FeedElementInfo("rdf_channel", "rss1"),
       "rss1:image": new ElementInfo("image", null, null, false),
       "rss1:textinput": new ElementInfo("textInput", null, null, false),
       "rss1:item": new ElementInfo("items", Cc[ENTRY_CONTRACTID], null, true),
     },
     "IN_RDF_CHANNEL": {
       "admin:generatorAgent": new ElementInfo("generator",
                                               Cc[GENERATOR_CONTRACTID],
                                               null, false),
       "dc:creator": new ElementInfo("authors", Cc[PERSON_CONTRACTID],
                                     rssAuthor, true),
       "dc:author": new ElementInfo("authors", Cc[PERSON_CONTRACTID],
                                    rssAuthor, true),
       "dc:contributor": new ElementInfo("contributors", Cc[PERSON_CONTRACTID],
                                          rssAuthor, true),
     },
     /********* ATOM 1.0 **********/
     "IN_ATOM": {
       "atom:author": new ElementInfo("authors", Cc[PERSON_CONTRACTID],
                                      null, true),
       "atom:generator": new ElementInfo("generator", Cc[GENERATOR_CONTRACTID],
                                         atomGenerator, false),
       "atom:contributor": new ElementInfo("contributors",  Cc[PERSON_CONTRACTID],
                                           null, true),
       "atom:link": new ElementInfo("links", null, null, true),
       "atom:logo": new ElementInfo("atom:logo", null, atomLogo, false),
       "atom:entry": new ElementInfo("entries", Cc[ENTRY_CONTRACTID],
                                     null, true)
     },
     "IN_ENTRIES": {
       "atom:author": new ElementInfo("authors", Cc[PERSON_CONTRACTID],
                                      null, true),
       "atom:contributor": new ElementInfo("contributors", Cc[PERSON_CONTRACTID],
                                           null, true),
       "atom:link": new ElementInfo("links", null, null, true),
     },
     /********* ATOM 0.3 **********/
     "IN_ATOM03": {
       "atom03:author": new ElementInfo("authors", Cc[PERSON_CONTRACTID],
                                        null, true),
       "atom03:contributor": new ElementInfo("contributors",
                                             Cc[PERSON_CONTRACTID],
                                             null, true),
       "atom03:link": new ElementInfo("links", null, null, true),
       "atom03:entry": new ElementInfo("atom03_entries", Cc[ENTRY_CONTRACTID],
                                       null, true),
       "atom03:generator": new ElementInfo("generator", Cc[GENERATOR_CONTRACTID],
                                           atomGenerator, false),
     },
     "IN_ATOM03_ENTRIES": {
       "atom03:author": new ElementInfo("authors", Cc[PERSON_CONTRACTID],
                                        null, true),
       "atom03:contributor": new ElementInfo("contributors",
                                             Cc[PERSON_CONTRACTID],
                                             null, true),
       "atom03:link": new ElementInfo("links", null, null, true),
       "atom03:entry": new ElementInfo("atom03_entries", Cc[ENTRY_CONTRACTID],
                                       null, true)
     }
   }
 }
 // See startElement for a long description of how feeds are processed.
 FeedProcessor.prototype = {
   // Set ourselves as the SAX handler, and set the base URI
   _init: function FP_init(uri) {
     this._reader.contentHandler = this;
     this._reader.errorHandler = this;
     this._result = Cc[FR_CONTRACTID].createInstance(Ci.nsIFeedResult);
     if (uri) {
       this._result.uri = uri;
       this._reader.baseURI = uri;
       this._xmlBaseStack[0] = uri;
     }
   },
   // This function is called once we figure out what type of feed
   // we're dealing with. Some feed types require digging a bit further
   // than the root.
   _docVerified: function FP_docVerified(version) {
     this._result.doc = Cc[FEED_CONTRACTID].createInstance(Ci.nsIFeed);
     this._result.doc.baseURI =
       this._xmlBaseStack[this._xmlBaseStack.length - 1];
     this._result.doc.fields = this._feed;
     this._result.version = version;
   },
   // When we're done with the feed, let the listener know what
   // happened.
   _sendResult: function FP_sendResult() {
     this._haveSentResult = true;
     try {
       // Can be null when a non-feed is fed to us
       if (this._result.doc)
         this._result.doc.normalize();
     }
     catch (e) {
       LOG("FIXME: " + e);
     }
     try {
       if (this.listener != null)
         this.listener.handleResult(this._result);
     }
     finally {
       this._result = null;
     }
   },
   // Parsing functions
   parseFromStream: function FP_parseFromStream(stream, uri) {
     this._init(uri);
     this._reader.parseFromStream(stream, null, stream.available(),
                                  "application/xml");
     this._reader = null;
   },
   parseFromString: function FP_parseFromString(inputString, uri) {
     this._init(uri);
     this._reader.parseFromString(inputString, "application/xml");
     this._reader = null;
   },
   parseAsync: function FP_parseAsync(requestObserver, uri) {
     this._init(uri);
     this._reader.parseAsync(requestObserver);
   },
   // nsIStreamListener
   // The XMLReader will throw sensible exceptions if these get called
   // out of order.
   onStartRequest: function FP_onStartRequest(request, context) {
     // this will throw if the request is not a channel, but so will nsParser.
     var channel = request.QueryInterface(Ci.nsIChannel);
     channel.contentType = "application/vnd.mozilla.maybe.feed";
     this._reader.onStartRequest(request, context);
   },
   onStopRequest: function FP_onStopRequest(request, context, statusCode) {
     try {
       this._reader.onStopRequest(request, context, statusCode);
     }
     finally {
       this._reader = null;
     }
   },
   onDataAvailable:
   function FP_onDataAvailable(request, context, inputStream, offset, count) {
     this._reader.onDataAvailable(request, context, inputStream, offset, count);
   },
   // nsISAXErrorHandler
   // We only care about fatal errors. When this happens, we may have
   // parsed through the feed metadata and some number of entries. The
   // listener can still show some of that data if it wants, and we'll
   // set the bozo bit to indicate we were unable to parse all the way
   // through.
   fatalError: function FP_reportError() {
     this._result.bozo = true;
     //XXX need to QI to FeedProgressListener
     if (!this._haveSentResult)
       this._sendResult();
   },
   // nsISAXContentHandler
   startDocument: function FP_startDocument() {
     //LOG("----------");
   },
   endDocument: function FP_endDocument() {
     if (!this._haveSentResult)
       this._sendResult();
   },
   // The transitions defined above identify elements that contain more
   // than just text. For example RSS items contain many fields, and so
   // do Atom authors. The only commonly used elements that contain
   // mixed content are Atom Text Constructs of type="xhtml", which we
   // delegate to another handler for cleaning. That leaves a couple
   // different types of elements to deal with: those that should occur
   // only once, such as title elements, and those that can occur
   // multiple times, such as the RSS category element and the Atom
   // link element. Most of the RSS1/DC elements can occur multiple
   // times in theory, but in practice, the only ones that do have
   // analogues in Atom.
   //
   // Some elements are also groups of attributes or sub-elements,
   // while others are simple text fields. For the most part, we don't
   // have to pay explicit attention to the simple text elements,
   // unless we want to post-process the resulting string to transform
   // it into some richer object like a Date or URI.
   //
   // Elements that have more sophisticated content models still end up
   // being dictionaries, whether they are based on attributes like RSS
   // cloud, sub-elements like Atom author, or even items and
   // entries. These elements are treated as "containers". It's
   // theoretically possible for a container to have an attribute with
   // the same universal name as a sub-element, but none of the feed
   // formats allow this by default, and I don't of any extension that
   // works this way.
   //
   startElement: function FP_startElement(uri, localName, qName, attributes) {
     this._buf = "";
     ++this._depth;
     var elementInfo;
     //LOG("<" + localName + ">");
     // Check for xml:base
     var base = attributes.getValueFromName(XMLNS, "base");
     if (base) {
       this._xmlBaseStack[this._depth] =
         strToURI(base, this._xmlBaseStack[this._xmlBaseStack.length - 1]);
     }
     // To identify the element we're dealing with, we look up the
     // namespace URI in our gNamespaces dictionary, which will give us
     // a "canonical" prefix for a namespace URI. For example, this
     // allows Dublin Core "creator" elements to be consistently mapped
     // to "dc:creator", for easy field access by consumer code. This
     // strategy also happens to shorten up our state table.
     var key =  this._prefixForNS(uri) + localName;
     // Check to see if we need to hand this off to our XHTML handler.
     // The elements we're dealing with will look like this:
     //
     // <title type="xhtml">
     //   <div xmlns="http://www.w3.org/1999/xhtml">
     //     A title with <b>bold</b> and <i>italics</i>.
     //   </div>
     // </title>
     //
     // When it returns in returnFromXHTMLHandler, the handler should
     // give us back a string like this:
     //
     //    "A title with <b>bold</b> and <i>italics</i>."
     //
     // The Atom spec explicitly says the div is not part of the content,
     // and explicitly allows whitespace collapsing.
     //
     if ((this._result.version == "atom" || this._result.version == "atom03") &&
         this._textConstructs[key] != null) {
       var type = attributes.getValueFromName("","type");
       if (type != null && type.indexOf("xhtml") >= 0) {
         this._xhtmlHandler =
           new XHTMLHandler(this, (this._result.version == "atom"));
         this._reader.contentHandler = this._xhtmlHandler;
         return;
       }
     }
     // Check our current state, and see if that state has a defined
     // transition. For example, this._trans["atom:entry"]["atom:author"]
     // will have one, and it tells us to add an item to our authors array.
     if (this._trans[this._state] && this._trans[this._state][key]) {
       elementInfo = this._trans[this._state][key];
     }
     else {
       // If we don't have a transition, hand off to extension handler
       this._extensionHandler = new ExtensionHandler(this);
       this._reader.contentHandler = this._extensionHandler;
       this._extensionHandler.startElement(uri, localName, qName, attributes);
       return;
     }
     // This distinguishes wrappers like 'channel' from elements
     // we'd actually like to do something with (which will test true).
     this._handlerStack[this._depth] = elementInfo;
     if (elementInfo.isWrapper) {
       this._state = "IN_" + elementInfo.fieldName.toUpperCase();
       this._stack.push([this._feed, this._state]);
     }
     else if (elementInfo.feedVersion) {
       this._state = "IN_" + elementInfo.fieldName.toUpperCase();
       // Check for the older RSS2 variants
       if (elementInfo.feedVersion == "rss2")
         elementInfo.feedVersion = this._findRSSVersion(attributes);
       else if (uri == RSS090NS)
         elementInfo.feedVersion = "rss090";
       this._docVerified(elementInfo.feedVersion);
       this._stack.push([this._feed, this._state]);
       this._mapAttributes(this._feed, attributes);
     }
     else {
       this._state = this._processComplexElement(elementInfo, attributes);
     }
   },
   // In the endElement handler, we decrement the stack and look
   // for cleanup/transition functions to execute. The second part
   // of the state transition works as above in startElement, but
   // the state we're looking for is prefixed with an underscore
   // to distinguish endElement events from startElement events.
   endElement:  function FP_endElement(uri, localName, qName) {
     var elementInfo = this._handlerStack[this._depth];
     //LOG("</" + localName + ">");
     if (elementInfo && !elementInfo.isWrapper)
       this._closeComplexElement(elementInfo);
     // cut down xml:base context
     if (this._xmlBaseStack.length == this._depth + 1)
       this._xmlBaseStack = this._xmlBaseStack.slice(0, this._depth);
     // our new state is whatever is at the top of the stack now
     if (this._stack.length > 0)
       this._state = this._stack[this._stack.length - 1][1];
     this._handlerStack = this._handlerStack.slice(0, this._depth);
     --this._depth;
   },
   // Buffer up character data. The buffer is cleared with every
   // opening element.
   characters: function FP_characters(data) {
     this._buf += data;
   },
   // TODO: It would be nice to check new prefixes here, and if they
   // don't conflict with the ones we've defined, throw them in a
   // dictionary to check.
   startPrefixMapping: function FP_startPrefixMapping(prefix, uri) {
   },
   endPrefixMapping: function FP_endPrefixMapping(prefix) {
   },
   processingInstruction: function FP_processingInstruction(target, data) {
     if (target == "xml-stylesheet") {
       var hrefAttribute = data.match(/href=[\"\'](.*?)[\"\']/);
       if (hrefAttribute && hrefAttribute.length == 2)
         this._result.stylesheet = strToURI(hrefAttribute[1], this._result.uri);
     }
   },
   // end of nsISAXContentHandler
   // Handle our more complicated elements--those that contain
   // attributes and child elements.
   _processComplexElement:
   function FP__processComplexElement(elementInfo, attributes) {
     var obj, key, prefix;
     // If the container is an entry/item, it'll need to have its
     // more esoteric properties put in the 'fields' property bag.
     if (elementInfo.containerClass == Cc[ENTRY_CONTRACTID]) {
       obj = elementInfo.containerClass.createInstance(Ci.nsIFeedEntry);
       obj.baseURI = this._xmlBaseStack[this._xmlBaseStack.length - 1];
       this._mapAttributes(obj.fields, attributes);
     }
     else if (elementInfo.containerClass) {
       obj = elementInfo.containerClass.createInstance(Ci.nsIFeedElementBase);
       obj.baseURI = this._xmlBaseStack[this._xmlBaseStack.length - 1];
       obj.attributes = attributes; // just set the SAX attributes
     }
     else {
       obj = Cc[BAG_CONTRACTID].createInstance(Ci.nsIWritablePropertyBag2);
       this._mapAttributes(obj, attributes);
     }
     // We should have a container/propertyBag that's had its
     // attributes processed. Now we need to attach it to its
     // container.
     var newProp;
     // First we'll see what's on top of the stack.
     var container = this._stack[this._stack.length - 1][0];
     // Check to see if it has the property
     var prop;
     try {
       prop = container.getProperty(elementInfo.fieldName);
     }
     catch(e) {
     }
     if (elementInfo.isArray) {
       if (!prop) {
         container.setPropertyAsInterface(elementInfo.fieldName,
                                          Cc[ARRAY_CONTRACTID].
                                          createInstance(Ci.nsIMutableArray));
       }
       newProp = container.getProperty(elementInfo.fieldName);
       // XXX This QI should not be necessary, but XPConnect seems to fly
       // off the handle in the browser, and loses track of the interface
       // on large files. Bug 335638.
       newProp.QueryInterface(Ci.nsIMutableArray);
       newProp.appendElement(obj,false);
       // If new object is an nsIFeedContainer, we want to deal with
       // its member nsIPropertyBag instead.
       if (isIFeedContainer(obj))
         newProp = obj.fields;
     }
     else {
       // If it doesn't, set it.
       if (!prop) {
         container.setPropertyAsInterface(elementInfo.fieldName,obj);
       }
       newProp = container.getProperty(elementInfo.fieldName);
     }
     // make our new state name, and push the property onto the stack
     var newState = "IN_" + elementInfo.fieldName.toUpperCase();
     this._stack.push([newProp, newState, obj]);
     return newState;
   },
   // Sometimes we need reconcile the element content with the object
   // model for a given feed. We use helper functions to do the
   // munging, but we need to identify array types here, so the munging
   // happens only to the last element of an array.
   _closeComplexElement: function FP__closeComplexElement(elementInfo) {
     var stateTuple = this._stack.pop();
     var container = stateTuple[0];
     var containerParent = stateTuple[2];
     var element = null;
     var isArray = isIArray(container);
     // If it's an array and we have to post-process,
     // grab the last element
     if (isArray)
       element = container.queryElementAt(container.length - 1, Ci.nsISupports);
     else
       element = container;
     // Run the post-processing function if there is one.
     if (elementInfo.closeFunc)
       element = elementInfo.closeFunc(this._buf, element);
     // If an nsIFeedContainer was on top of the stack,
     // we need to normalize it
     if (elementInfo.containerClass == Cc[ENTRY_CONTRACTID])
       containerParent.normalize();
     // If it's an array, re-set the last element
     if (isArray)
       container.replaceElementAt(element, container.length - 1, false);
   },
   _prefixForNS: function FP_prefixForNS(uri) {
     if (!uri)
       return "";
     var prefix = gNamespaces[uri];
     if (prefix)
       return prefix + ":";
     if (uri.toLowerCase().indexOf("http://backend.userland.com") == 0)
       return "";
     else
       return null;
   },
   _mapAttributes: function FP__mapAttributes(bag, attributes) {
     // Cycle through the attributes, and set our properties using the
     // prefix:localNames we find in our namespace dictionary.
     for (var i = 0; i < attributes.length; ++i) {
       var key = this._prefixForNS(attributes.getURI(i)) + attributes.getLocalName(i);
       var val = attributes.getValue(i);
       bag.setPropertyAsAString(key, val);
     }
   },
   // Only for RSS2esque formats
   _findRSSVersion: function FP__findRSSVersion(attributes) {
     var versionAttr = attributes.getValueFromName("", "version").trim();
     var versions = { "0.91":"rss091",
                      "0.92":"rss092",
                      "0.93":"rss093",
                      "0.94":"rss094" }
     if (versions[versionAttr])
       return versions[versionAttr];
     if (versionAttr.substr(0,2) != "2.")
       return "rssUnknown";
     return "rss2";
   },
   // unknown element values are returned here. See startElement above
   // for how this works.
   returnFromExtHandler:
   function FP_returnExt(uri, localName, chars, attributes) {
     --this._depth;
     // take control of the SAX events
     this._reader.contentHandler = this;
     if (localName == null && chars == null)
       return;
     // we don't take random elements inside rdf:RDF
     if (this._state == "IN_RDF")
       return;
     // Grab the top of the stack
     var top = this._stack[this._stack.length - 1];
     if (!top)
       return;
     var container = top[0];
     // Grab the last element if it's an array
     if (isIArray(container)) {
       var contract = this._handlerStack[this._depth].containerClass;
       // check if it's something specific, but not an entry
       if (contract && contract != Cc[ENTRY_CONTRACTID]) {
         var el = container.queryElementAt(container.length - 1,
                                           Ci.nsIFeedElementBase);
         // XXX there must be a way to flatten these interfaces
         if (contract == Cc[PERSON_CONTRACTID])
           el.QueryInterface(Ci.nsIFeedPerson);
         else
           return; // don't know about this interface
         var propName = localName;
         var prefix = gNamespaces[uri];
         // synonyms
         if ((uri == "" ||
              prefix &&
              ((prefix.indexOf("atom") > -1) ||
               (prefix.indexOf("rss") > -1))) &&
             (propName == "url" || propName == "href"))
           propName = "uri";
         try {
           if (el[propName] !== "undefined") {
             var propValue = chars;
             // convert URI-bearing values to an nsIURI
             if (propName == "uri") {
               var base = this._xmlBaseStack[this._xmlBaseStack.length - 1];
               propValue = strToURI(chars, base);
             }
             el[propName] = propValue;
           }
         }
         catch(e) {
           // ignore XPConnect errors
         }
         // the rest of the function deals with entry- and feed-level stuff
         return;
       }
       else {
         container = container.queryElementAt(container.length - 1,
                                              Ci.nsIWritablePropertyBag2);
       }
     }
     // Make the buffer our new property
     var propName = this._prefixForNS(uri) + localName;
     // But, it could be something containing HTML. If so,
     // we need to know about that.
     if (this._textConstructs[propName] != null &&
         this._handlerStack[this._depth].containerClass !== null) {
       var newProp = Cc[TEXTCONSTRUCT_CONTRACTID].
                     createInstance(Ci.nsIFeedTextConstruct);
       newProp.text = chars;
       // Look up the default type in our table
       var type = this._textConstructs[propName];
       var typeAttribute = attributes.getValueFromName("","type");
       if (this._result.version == "atom" && typeAttribute != null) {
         type = typeAttribute;
       }
       else if (this._result.version == "atom03" && typeAttribute != null) {
         if (typeAttribute.toLowerCase().indexOf("xhtml") >= 0) {
           type = "xhtml";
         }
         else if (typeAttribute.toLowerCase().indexOf("html") >= 0) {
           type = "html";
         }
         else if (typeAttribute.toLowerCase().indexOf("text") >= 0) {
           type = "text";
         }
       }
       // If it's rss feed-level description, it's not supposed to have html
       if (this._result.version.indexOf("rss") >= 0 &&
           this._handlerStack[this._depth].containerClass != ENTRY_CONTRACTID) {
         type = "text";
       }
       newProp.type = type;
       newProp.base = this._xmlBaseStack[this._xmlBaseStack.length - 1];
       container.setPropertyAsInterface(propName, newProp);
     }
     else {
       container.setPropertyAsAString(propName, chars);
     }
   },
   // Sometimes, we'll hand off SAX handling duties to an XHTMLHandler
   // (see above) that will scrape out non-XHTML stuff, normalize
   // namespaces, and remove the wrapper div from Atom 1.0. When the
   // XHTMLHandler is done, it'll callback here.
   returnFromXHTMLHandler:
   function FP_returnFromXHTMLHandler(chars, uri, localName, qName) {
     // retake control of the SAX content events
     this._reader.contentHandler = this;
     // Grab the top of the stack
     var top = this._stack[this._stack.length - 1];
     if (!top)
       return;
     var container = top[0];
     // Assign the property
     var newProp =  newProp = Cc[TEXTCONSTRUCT_CONTRACTID].
                    createInstance(Ci.nsIFeedTextConstruct);
     newProp.text = chars;
     newProp.type = "xhtml";
     newProp.base = this._xmlBaseStack[this._xmlBaseStack.length - 1];
     container.setPropertyAsInterface(this._prefixForNS(uri) + localName,
                                      newProp);
     // XHTML will cause us to peek too far. The XHTML handler will
     // send us an end element to call. RFC4287-valid feeds allow a
     // more graceful way to handle this. Unfortunately, we can't count
     // on compliance at this point.
     this.endElement(uri, localName, qName);
   },
   // XPCOM stuff
   classID: FP_CLASSID,
   QueryInterface: XPCOMUtils.generateQI(
     [Ci.nsIFeedProcessor, Ci.nsISAXContentHandler, Ci.nsISAXErrorHandler,
      Ci.nsIStreamListener, Ci.nsIRequestObserver]
   )
 }
 var components = [FeedProcessor, FeedResult, Feed, Entry,
                   TextConstruct, Generator, Person];
 this.NSGetFactory = XPCOMUtils.generateNSGetFactory(components);