michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: "use strict";
michael@0: 
michael@0: this.EXPORTED_SYMBOLS = [ "Feeds" ];
michael@0: 
michael@0: Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
michael@0: 
michael@0: XPCOMUtils.defineLazyModuleGetter(this, "BrowserUtils",
michael@0:                                   "resource://gre/modules/BrowserUtils.jsm");
michael@0: 
michael@0: const Ci = Components.interfaces;
michael@0: 
michael@0: this.Feeds = {
michael@0: 
michael@0:   /**
michael@0:    * isValidFeed: checks whether the given data represents a valid feed.
michael@0:    *
michael@0:    * @param  aLink
michael@0:    *         An object representing a feed with title, href and type.
michael@0:    * @param  aPrincipal
michael@0:    *         The principal of the document, used for security check.
michael@0:    * @param  aIsFeed
michael@0:    *         Whether this is already a known feed or not, if true only a security
michael@0:    *         check will be performed.
michael@0:    */
michael@0:   isValidFeed: function(aLink, aPrincipal, aIsFeed) {
michael@0:     if (!aLink || !aPrincipal)
michael@0:       return false;
michael@0: 
michael@0:     var type = aLink.type.toLowerCase().replace(/^\s+|\s*(?:;.*)?$/g, "");
michael@0:     if (!aIsFeed) {
michael@0:       aIsFeed = (type == "application/rss+xml" ||
michael@0:                  type == "application/atom+xml");
michael@0:     }
michael@0: 
michael@0:     if (aIsFeed) {
michael@0:       try {
michael@0:         BrowserUtils.urlSecurityCheck(aLink.href, aPrincipal,
michael@0:                                       Ci.nsIScriptSecurityManager.DISALLOW_INHERIT_PRINCIPAL);
michael@0:         return type || "application/rss+xml";
michael@0:       }
michael@0:       catch(ex) {
michael@0:       }
michael@0:     }
michael@0: 
michael@0:     return null;
michael@0:   },
michael@0: 
michael@0: };