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 file,
michael@0:  * You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: "use strict";
michael@0: 
michael@0: this.EXPORTED_SYMBOLS = ["Social", "CreateSocialStatusWidget",
michael@0:                          "CreateSocialMarkWidget", "OpenGraphBuilder",
michael@0:                          "DynamicResizeWatcher", "sizeSocialPanelToContent"];
michael@0: 
michael@0: const Ci = Components.interfaces;
michael@0: const Cc = Components.classes;
michael@0: const Cu = Components.utils;
michael@0: 
michael@0: // The minimum sizes for the auto-resize panel code.
michael@0: const PANEL_MIN_HEIGHT = 100;
michael@0: const PANEL_MIN_WIDTH = 330;
michael@0: 
michael@0: Cu.import("resource://gre/modules/Services.jsm");
michael@0: Cu.import("resource://gre/modules/XPCOMUtils.jsm");
michael@0: 
michael@0: XPCOMUtils.defineLazyModuleGetter(this, "CustomizableUI",
michael@0:   "resource:///modules/CustomizableUI.jsm");
michael@0: XPCOMUtils.defineLazyModuleGetter(this, "SocialService",
michael@0:   "resource://gre/modules/SocialService.jsm");
michael@0: XPCOMUtils.defineLazyModuleGetter(this, "PlacesUtils",
michael@0:   "resource://gre/modules/PlacesUtils.jsm");
michael@0: XPCOMUtils.defineLazyModuleGetter(this, "PrivateBrowsingUtils",
michael@0:   "resource://gre/modules/PrivateBrowsingUtils.jsm");
michael@0: XPCOMUtils.defineLazyModuleGetter(this, "Promise",
michael@0:   "resource://gre/modules/Promise.jsm");
michael@0: 
michael@0: XPCOMUtils.defineLazyServiceGetter(this, "unescapeService",
michael@0:                                    "@mozilla.org/feed-unescapehtml;1",
michael@0:                                    "nsIScriptableUnescapeHTML");
michael@0: 
michael@0: function promiseSetAnnotation(aURI, providerList) {
michael@0:   let deferred = Promise.defer();
michael@0: 
michael@0:   // Delaying to catch issues with asynchronous behavior while waiting
michael@0:   // to implement asynchronous annotations in bug 699844.
michael@0:   Services.tm.mainThread.dispatch(function() {
michael@0:     try {
michael@0:       if (providerList && providerList.length > 0) {
michael@0:         PlacesUtils.annotations.setPageAnnotation(
michael@0:           aURI, "social/mark", JSON.stringify(providerList), 0,
michael@0:           PlacesUtils.annotations.EXPIRE_WITH_HISTORY);
michael@0:       } else {
michael@0:         PlacesUtils.annotations.removePageAnnotation(aURI, "social/mark");
michael@0:       }
michael@0:     } catch(e) {
michael@0:       Cu.reportError("SocialAnnotation failed: " + e);
michael@0:     }
michael@0:     deferred.resolve();
michael@0:   }, Ci.nsIThread.DISPATCH_NORMAL);
michael@0: 
michael@0:   return deferred.promise;
michael@0: }
michael@0: 
michael@0: function promiseGetAnnotation(aURI) {
michael@0:   let deferred = Promise.defer();
michael@0: 
michael@0:   // Delaying to catch issues with asynchronous behavior while waiting
michael@0:   // to implement asynchronous annotations in bug 699844.
michael@0:   Services.tm.mainThread.dispatch(function() {
michael@0:     let val = null;
michael@0:     try {
michael@0:       val = PlacesUtils.annotations.getPageAnnotation(aURI, "social/mark");
michael@0:     } catch (ex) { }
michael@0: 
michael@0:     deferred.resolve(val);
michael@0:   }, Ci.nsIThread.DISPATCH_NORMAL);
michael@0: 
michael@0:   return deferred.promise;
michael@0: }
michael@0: 
michael@0: this.Social = {
michael@0:   initialized: false,
michael@0:   lastEventReceived: 0,
michael@0:   providers: [],
michael@0:   _disabledForSafeMode: false,
michael@0: 
michael@0:   init: function Social_init() {
michael@0:     this._disabledForSafeMode = Services.appinfo.inSafeMode && this.enabled;
michael@0:     let deferred = Promise.defer();
michael@0: 
michael@0:     if (this.initialized) {
michael@0:       deferred.resolve(true);
michael@0:       return deferred.promise;
michael@0:     }
michael@0:     this.initialized = true;
michael@0:     // if SocialService.hasEnabledProviders, retreive the providers so the
michael@0:     // front-end can generate UI
michael@0:     if (SocialService.hasEnabledProviders) {
michael@0:       // Retrieve the current set of providers, and set the current provider.
michael@0:       SocialService.getOrderedProviderList(function (providers) {
michael@0:         Social._updateProviderCache(providers);
michael@0:         Social._updateWorkerState(SocialService.enabled);
michael@0:         deferred.resolve(false);
michael@0:       });
michael@0:     } else {
michael@0:       deferred.resolve(false);
michael@0:     }
michael@0: 
michael@0:     // Register an observer for changes to the provider list
michael@0:     SocialService.registerProviderListener(function providerListener(topic, origin, providers) {
michael@0:       // An engine change caused by adding/removing a provider should notify.
michael@0:       // any providers we receive are enabled in the AddonsManager
michael@0:       if (topic == "provider-installed" || topic == "provider-uninstalled") {
michael@0:         // installed/uninstalled do not send the providers param
michael@0:         Services.obs.notifyObservers(null, "social:" + topic, origin);
michael@0:         return;
michael@0:       }
michael@0:       if (topic == "provider-enabled") {
michael@0:         Social._updateProviderCache(providers);
michael@0:         Social._updateWorkerState(true);
michael@0:         Services.obs.notifyObservers(null, "social:" + topic, origin);
michael@0:         return;
michael@0:       }
michael@0:       if (topic == "provider-disabled") {
michael@0:         // a provider was removed from the list of providers, that does not
michael@0:         // affect worker state for other providers
michael@0:         Social._updateProviderCache(providers);
michael@0:         Social._updateWorkerState(providers.length > 0);
michael@0:         Services.obs.notifyObservers(null, "social:" + topic, origin);
michael@0:         return;
michael@0:       }
michael@0:       if (topic == "provider-update") {
michael@0:         // a provider has self-updated its manifest, we need to update our cache
michael@0:         // and reload the provider.
michael@0:         Social._updateProviderCache(providers);
michael@0:         let provider = Social._getProviderFromOrigin(origin);
michael@0:         provider.reload();
michael@0:       }
michael@0:     });
michael@0:     return deferred.promise;
michael@0:   },
michael@0: 
michael@0:   _updateWorkerState: function(enable) {
michael@0:     [p.enabled = enable for (p of Social.providers) if (p.enabled != enable)];
michael@0:   },
michael@0: 
michael@0:   // Called to update our cache of providers and set the current provider
michael@0:   _updateProviderCache: function (providers) {
michael@0:     this.providers = providers;
michael@0:     Services.obs.notifyObservers(null, "social:providers-changed", null);
michael@0:   },
michael@0: 
michael@0:   get enabled() {
michael@0:     return !this._disabledForSafeMode && this.providers.length > 0;
michael@0:   },
michael@0: 
michael@0:   toggleNotifications: function SocialNotifications_toggle() {
michael@0:     let prefValue = Services.prefs.getBoolPref("social.toast-notifications.enabled");
michael@0:     Services.prefs.setBoolPref("social.toast-notifications.enabled", !prefValue);
michael@0:   },
michael@0: 
michael@0:   _getProviderFromOrigin: function (origin) {
michael@0:     for (let p of this.providers) {
michael@0:       if (p.origin == origin) {
michael@0:         return p;
michael@0:       }
michael@0:     }
michael@0:     return null;
michael@0:   },
michael@0: 
michael@0:   getManifestByOrigin: function(origin) {
michael@0:     return SocialService.getManifestByOrigin(origin);
michael@0:   },
michael@0: 
michael@0:   installProvider: function(doc, data, installCallback) {
michael@0:     SocialService.installProvider(doc, data, installCallback);
michael@0:   },
michael@0: 
michael@0:   uninstallProvider: function(origin, aCallback) {
michael@0:     SocialService.uninstallProvider(origin, aCallback);
michael@0:   },
michael@0: 
michael@0:   // Activation functionality
michael@0:   activateFromOrigin: function (origin, callback) {
michael@0:     // For now only "builtin" providers can be activated.  It's OK if the
michael@0:     // provider has already been activated - we still get called back with it.
michael@0:     SocialService.addBuiltinProvider(origin, callback);
michael@0:   },
michael@0: 
michael@0:   // Page Marking functionality
michael@0:   isURIMarked: function(origin, aURI, aCallback) {
michael@0:     promiseGetAnnotation(aURI).then(function(val) {
michael@0:       if (val) {
michael@0:         let providerList = JSON.parse(val);
michael@0:         val = providerList.indexOf(origin) >= 0;
michael@0:       }
michael@0:       aCallback(!!val);
michael@0:     }).then(null, Cu.reportError);
michael@0:   },
michael@0: 
michael@0:   markURI: function(origin, aURI, aCallback) {
michael@0:     // update or set our annotation
michael@0:     promiseGetAnnotation(aURI).then(function(val) {
michael@0: 
michael@0:       let providerList = val ? JSON.parse(val) : [];
michael@0:       let marked = providerList.indexOf(origin) >= 0;
michael@0:       if (marked)
michael@0:         return;
michael@0:       providerList.push(origin);
michael@0:       // we allow marking links in a page that may not have been visited yet.
michael@0:       // make sure there is a history entry for the uri, then annotate it.
michael@0:       let place = {
michael@0:         uri: aURI,
michael@0:         visits: [{
michael@0:           visitDate: Date.now() + 1000,
michael@0:           transitionType: Ci.nsINavHistoryService.TRANSITION_LINK
michael@0:         }]
michael@0:       };
michael@0:       PlacesUtils.asyncHistory.updatePlaces(place, {
michael@0:         handleError: function () Cu.reportError("couldn't update history for socialmark annotation"),
michael@0:         handleResult: function () {},
michael@0:         handleCompletion: function () {
michael@0:           promiseSetAnnotation(aURI, providerList).then(function() {
michael@0:             if (aCallback)
michael@0:               schedule(function() { aCallback(true); } );
michael@0:           }).then(null, Cu.reportError);
michael@0:         }
michael@0:       });
michael@0:     }).then(null, Cu.reportError);
michael@0:   },
michael@0: 
michael@0:   unmarkURI: function(origin, aURI, aCallback) {
michael@0:     // this should not be called if this.provider or the port is null
michael@0:     // set our annotation
michael@0:     promiseGetAnnotation(aURI).then(function(val) {
michael@0:       let providerList = val ? JSON.parse(val) : [];
michael@0:       let marked = providerList.indexOf(origin) >= 0;
michael@0:       if (marked) {
michael@0:         // remove the annotation
michael@0:         providerList.splice(providerList.indexOf(origin), 1);
michael@0:         promiseSetAnnotation(aURI, providerList).then(function() {
michael@0:           if (aCallback)
michael@0:             schedule(function() { aCallback(false); } );
michael@0:         }).then(null, Cu.reportError);
michael@0:       }
michael@0:     }).then(null, Cu.reportError);
michael@0:   },
michael@0: 
michael@0:   setErrorListener: function(iframe, errorHandler) {
michael@0:     if (iframe.socialErrorListener)
michael@0:       return iframe.socialErrorListener;
michael@0:     return new SocialErrorListener(iframe, errorHandler);
michael@0:   }
michael@0: };
michael@0: 
michael@0: function schedule(callback) {
michael@0:   Services.tm.mainThread.dispatch(callback, Ci.nsIThread.DISPATCH_NORMAL);
michael@0: }
michael@0: 
michael@0: function CreateSocialStatusWidget(aId, aProvider) {
michael@0:   if (!aProvider.statusURL)
michael@0:     return;
michael@0:   let widget = CustomizableUI.getWidget(aId);
michael@0:   // The widget is only null if we've created then destroyed the widget.
michael@0:   // Once we've actually called createWidget the provider will be set to
michael@0:   // PROVIDER_API.
michael@0:   if (widget && widget.provider == CustomizableUI.PROVIDER_API)
michael@0:     return;
michael@0: 
michael@0:   CustomizableUI.createWidget({
michael@0:     id: aId,
michael@0:     type: 'custom',
michael@0:     removable: true,
michael@0:     defaultArea: CustomizableUI.AREA_NAVBAR,
michael@0:     onBuild: function(aDocument) {
michael@0:       let node = aDocument.createElement('toolbarbutton');
michael@0:       node.id = this.id;
michael@0:       node.setAttribute('class', 'toolbarbutton-1 chromeclass-toolbar-additional social-status-button');
michael@0:       node.setAttribute('type', "badged");
michael@0:       node.style.listStyleImage = "url(" + (aProvider.icon32URL || aProvider.iconURL) + ")";
michael@0:       node.setAttribute("origin", aProvider.origin);
michael@0:       node.setAttribute("label", aProvider.name);
michael@0:       node.setAttribute("tooltiptext", aProvider.name);
michael@0:       node.setAttribute("oncommand", "SocialStatus.showPopup(this);");
michael@0: 
michael@0:       if (PrivateBrowsingUtils.isWindowPrivate(aDocument.defaultView))
michael@0:         node.setAttribute("disabled", "true");
michael@0: 
michael@0:       return node;
michael@0:     }
michael@0:   });
michael@0: };
michael@0: 
michael@0: function CreateSocialMarkWidget(aId, aProvider) {
michael@0:   if (!aProvider.markURL)
michael@0:     return;
michael@0:   let widget = CustomizableUI.getWidget(aId);
michael@0:   // The widget is only null if we've created then destroyed the widget.
michael@0:   // Once we've actually called createWidget the provider will be set to
michael@0:   // PROVIDER_API.
michael@0:   if (widget && widget.provider == CustomizableUI.PROVIDER_API)
michael@0:     return;
michael@0: 
michael@0:   CustomizableUI.createWidget({
michael@0:     id: aId,
michael@0:     type: 'custom',
michael@0:     removable: true,
michael@0:     defaultArea: CustomizableUI.AREA_NAVBAR,
michael@0:     onBuild: function(aDocument) {
michael@0:       let node = aDocument.createElement('toolbarbutton');
michael@0:       node.id = this.id;
michael@0:       node.setAttribute('class', 'toolbarbutton-1 chromeclass-toolbar-additional social-mark-button');
michael@0:       node.setAttribute('type', "socialmark");
michael@0:       node.style.listStyleImage = "url(" + (aProvider.unmarkedIcon || aProvider.icon32URL || aProvider.iconURL) + ")";
michael@0:       node.setAttribute("origin", aProvider.origin);
michael@0:       node.setAttribute("oncommand", "this.markCurrentPage();");
michael@0: 
michael@0:       let window = aDocument.defaultView;
michael@0:       let menuLabel = window.gNavigatorBundle.getFormattedString("social.markpageMenu.label", [aProvider.name]);
michael@0:       node.setAttribute("label", menuLabel);
michael@0:       node.setAttribute("tooltiptext", menuLabel);
michael@0: 
michael@0:       return node;
michael@0:     }
michael@0:   });
michael@0: };
michael@0: 
michael@0: // Error handling class used to listen for network errors in the social frames
michael@0: // and replace them with a social-specific error page
michael@0: function SocialErrorListener(iframe, errorHandler) {
michael@0:   this.setErrorMessage = errorHandler;
michael@0:   this.iframe = iframe;
michael@0:   iframe.socialErrorListener = this;
michael@0:   iframe.docShell.QueryInterface(Ci.nsIInterfaceRequestor)
michael@0:                                    .getInterface(Ci.nsIWebProgress)
michael@0:                                    .addProgressListener(this,
michael@0:                                                         Ci.nsIWebProgress.NOTIFY_STATE_REQUEST |
michael@0:                                                         Ci.nsIWebProgress.NOTIFY_LOCATION);
michael@0: }
michael@0: 
michael@0: SocialErrorListener.prototype = {
michael@0:   QueryInterface: XPCOMUtils.generateQI([Ci.nsIWebProgressListener,
michael@0:                                          Ci.nsISupportsWeakReference,
michael@0:                                          Ci.nsISupports]),
michael@0: 
michael@0:   remove: function() {
michael@0:     this.iframe.docShell.QueryInterface(Ci.nsIInterfaceRequestor)
michael@0:                                      .getInterface(Ci.nsIWebProgress)
michael@0:                                      .removeProgressListener(this);
michael@0:     delete this.iframe.socialErrorListener;
michael@0:   },
michael@0: 
michael@0:   onStateChange: function SPL_onStateChange(aWebProgress, aRequest, aState, aStatus) {
michael@0:     let failure = false;
michael@0:     if ((aState & Ci.nsIWebProgressListener.STATE_STOP)) {
michael@0:       if (aRequest instanceof Ci.nsIHttpChannel) {
michael@0:         try {
michael@0:           // Change the frame to an error page on 4xx (client errors)
michael@0:           // and 5xx (server errors)
michael@0:           failure = aRequest.responseStatus >= 400 &&
michael@0:                     aRequest.responseStatus < 600;
michael@0:         } catch (e) {}
michael@0:       }
michael@0:     }
michael@0: 
michael@0:     // Calling cancel() will raise some OnStateChange notifications by itself,
michael@0:     // so avoid doing that more than once
michael@0:     if (failure && aStatus != Components.results.NS_BINDING_ABORTED) {
michael@0:       aRequest.cancel(Components.results.NS_BINDING_ABORTED);
michael@0:       let provider = Social._getProviderFromOrigin(this.iframe.getAttribute("origin"));
michael@0:       provider.errorState = "content-error";
michael@0:       this.setErrorMessage(aWebProgress.QueryInterface(Ci.nsIDocShell)
michael@0:                               .chromeEventHandler);
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   onLocationChange: function SPL_onLocationChange(aWebProgress, aRequest, aLocation, aFlags) {
michael@0:     if (aFlags & Ci.nsIWebProgressListener.LOCATION_CHANGE_ERROR_PAGE) {
michael@0:       aRequest.cancel(Components.results.NS_BINDING_ABORTED);
michael@0:       let provider = Social._getProviderFromOrigin(this.iframe.getAttribute("origin"));
michael@0:       if (!provider.errorState)
michael@0:         provider.errorState = "content-error";
michael@0:       schedule(function() {
michael@0:         this.setErrorMessage(aWebProgress.QueryInterface(Ci.nsIDocShell)
michael@0:                               .chromeEventHandler);
michael@0:       }.bind(this));
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   onProgressChange: function SPL_onProgressChange() {},
michael@0:   onStatusChange: function SPL_onStatusChange() {},
michael@0:   onSecurityChange: function SPL_onSecurityChange() {},
michael@0: };
michael@0: 
michael@0: 
michael@0: function sizeSocialPanelToContent(panel, iframe) {
michael@0:   let doc = iframe.contentDocument;
michael@0:   if (!doc || !doc.body) {
michael@0:     return;
michael@0:   }
michael@0:   // We need an element to use for sizing our panel.  See if the body defines
michael@0:   // an id for that element, otherwise use the body itself.
michael@0:   let body = doc.body;
michael@0:   let bodyId = body.getAttribute("contentid");
michael@0:   if (bodyId) {
michael@0:     body = doc.getElementById(bodyId) || doc.body;
michael@0:   }
michael@0:   // offsetHeight/Width don't include margins, so account for that.
michael@0:   let cs = doc.defaultView.getComputedStyle(body);
michael@0:   let width = PANEL_MIN_WIDTH;
michael@0:   let height = PANEL_MIN_HEIGHT;
michael@0:   // if the panel is preloaded prior to being shown, cs will be null.  in that
michael@0:   // case use the minimum size for the panel until it is shown.
michael@0:   if (cs) {
michael@0:     let computedHeight = parseInt(cs.marginTop) + body.offsetHeight + parseInt(cs.marginBottom);
michael@0:     height = Math.max(computedHeight, height);
michael@0:     let computedWidth = parseInt(cs.marginLeft) + body.offsetWidth + parseInt(cs.marginRight);
michael@0:     width = Math.max(computedWidth, width);
michael@0:   }
michael@0:   iframe.style.width = width + "px";
michael@0:   iframe.style.height = height + "px";
michael@0:   // since we do not use panel.sizeTo, we need to adjust the arrow ourselves
michael@0:   if (panel.state == "open")
michael@0:     panel.adjustArrowPosition();
michael@0: }
michael@0: 
michael@0: function DynamicResizeWatcher() {
michael@0:   this._mutationObserver = null;
michael@0: }
michael@0: 
michael@0: DynamicResizeWatcher.prototype = {
michael@0:   start: function DynamicResizeWatcher_start(panel, iframe) {
michael@0:     this.stop(); // just in case...
michael@0:     let doc = iframe.contentDocument;
michael@0:     this._mutationObserver = new iframe.contentWindow.MutationObserver(function(mutations) {
michael@0:       sizeSocialPanelToContent(panel, iframe);
michael@0:     });
michael@0:     // Observe anything that causes the size to change.
michael@0:     let config = {attributes: true, characterData: true, childList: true, subtree: true};
michael@0:     this._mutationObserver.observe(doc, config);
michael@0:     // and since this may be setup after the load event has fired we do an
michael@0:     // initial resize now.
michael@0:     sizeSocialPanelToContent(panel, iframe);
michael@0:   },
michael@0:   stop: function DynamicResizeWatcher_stop() {
michael@0:     if (this._mutationObserver) {
michael@0:       try {
michael@0:         this._mutationObserver.disconnect();
michael@0:       } catch (ex) {
michael@0:         // may get "TypeError: can't access dead object" which seems strange,
michael@0:         // but doesn't seem to indicate a real problem, so ignore it...
michael@0:       }
michael@0:       this._mutationObserver = null;
michael@0:     }
michael@0:   }
michael@0: }
michael@0: 
michael@0: 
michael@0: this.OpenGraphBuilder = {
michael@0:   generateEndpointURL: function(URLTemplate, pageData) {
michael@0:     // support for existing oexchange style endpoints by supporting their
michael@0:     // querystring arguments. parse the query string template and do
michael@0:     // replacements where necessary the query names may be different than ours,
michael@0:     // so we could see u=%{url} or url=%{url}
michael@0:     let [endpointURL, queryString] = URLTemplate.split("?");
michael@0:     let query = {};
michael@0:     if (queryString) {
michael@0:       queryString.split('&').forEach(function (val) {
michael@0:         let [name, value] = val.split('=');
michael@0:         let p = /%\{(.+)\}/.exec(value);
michael@0:         if (!p) {
michael@0:           // preserve non-template query vars
michael@0:           query[name] = value;
michael@0:         } else if (pageData[p[1]]) {
michael@0:           query[name] = pageData[p[1]];
michael@0:         } else if (p[1] == "body") {
michael@0:           // build a body for emailers
michael@0:           let body = "";
michael@0:           if (pageData.title)
michael@0:             body += pageData.title + "\n\n";
michael@0:           if (pageData.description)
michael@0:             body += pageData.description + "\n\n";
michael@0:           if (pageData.text)
michael@0:             body += pageData.text + "\n\n";
michael@0:           body += pageData.url;
michael@0:           query["body"] = body;
michael@0:         }
michael@0:       });
michael@0:     }
michael@0:     var str = [];
michael@0:     for (let p in query)
michael@0:        str.push(p + "=" + encodeURIComponent(query[p]));
michael@0:     if (str.length)
michael@0:       endpointURL = endpointURL + "?" + str.join("&");
michael@0:     return endpointURL;
michael@0:   },
michael@0: 
michael@0:   getData: function(browser) {
michael@0:     let res = {
michael@0:       url: this._validateURL(browser, browser.currentURI.spec),
michael@0:       title: browser.contentDocument.title,
michael@0:       previews: []
michael@0:     };
michael@0:     this._getMetaData(browser, res);
michael@0:     this._getLinkData(browser, res);
michael@0:     this._getPageData(browser, res);
michael@0:     return res;
michael@0:   },
michael@0: 
michael@0:   _getMetaData: function(browser, o) {
michael@0:     // query for standardized meta data
michael@0:     let els = browser.contentDocument
michael@0:                   .querySelectorAll("head > meta[property], head > meta[name]");
michael@0:     if (els.length < 1)
michael@0:       return;
michael@0:     let url;
michael@0:     for (let el of els) {
michael@0:       let value = el.getAttribute("content")
michael@0:       if (!value)
michael@0:         continue;
michael@0:       value = unescapeService.unescape(value.trim());
michael@0:       switch (el.getAttribute("property") || el.getAttribute("name")) {
michael@0:         case "title":
michael@0:         case "og:title":
michael@0:           o.title = value;
michael@0:           break;
michael@0:         case "description":
michael@0:         case "og:description":
michael@0:           o.description = value;
michael@0:           break;
michael@0:         case "og:site_name":
michael@0:           o.siteName = value;
michael@0:           break;
michael@0:         case "medium":
michael@0:         case "og:type":
michael@0:           o.medium = value;
michael@0:           break;
michael@0:         case "og:video":
michael@0:           url = this._validateURL(browser, value);
michael@0:           if (url)
michael@0:             o.source = url;
michael@0:           break;
michael@0:         case "og:url":
michael@0:           url = this._validateURL(browser, value);
michael@0:           if (url)
michael@0:             o.url = url;
michael@0:           break;
michael@0:         case "og:image":
michael@0:           url = this._validateURL(browser, value);
michael@0:           if (url)
michael@0:             o.previews.push(url);
michael@0:           break;
michael@0:       }
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   _getLinkData: function(browser, o) {
michael@0:     let els = browser.contentDocument
michael@0:                   .querySelectorAll("head > link[rel], head > link[id]");
michael@0:     for (let el of els) {
michael@0:       let url = el.getAttribute("href");
michael@0:       if (!url)
michael@0:         continue;
michael@0:       url = this._validateURL(browser, unescapeService.unescape(url.trim()));
michael@0:       switch (el.getAttribute("rel") || el.getAttribute("id")) {
michael@0:         case "shorturl":
michael@0:         case "shortlink":
michael@0:           o.shortUrl = url;
michael@0:           break;
michael@0:         case "canonicalurl":
michael@0:         case "canonical":
michael@0:           o.url = url;
michael@0:           break;
michael@0:         case "image_src":
michael@0:           o.previews.push(url);
michael@0:           break;
michael@0:       }
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   // scrape through the page for data we want
michael@0:   _getPageData: function(browser, o) {
michael@0:     if (o.previews.length < 1)
michael@0:       o.previews = this._getImageUrls(browser);
michael@0:   },
michael@0: 
michael@0:   _validateURL: function(browser, url) {
michael@0:     let uri = Services.io.newURI(browser.currentURI.resolve(url), null, null);
michael@0:     if (["http", "https", "ftp", "ftps"].indexOf(uri.scheme) < 0)
michael@0:       return null;
michael@0:     uri.userPass = "";
michael@0:     return uri.spec;
michael@0:   },
michael@0: 
michael@0:   _getImageUrls: function(browser) {
michael@0:     let l = [];
michael@0:     let els = browser.contentDocument.querySelectorAll("img");
michael@0:     for (let el of els) {
michael@0:       let content = el.getAttribute("src");
michael@0:       if (content) {
michael@0:         l.push(this._validateURL(browser, unescapeService.unescape(content)));
michael@0:         // we don't want a billion images
michael@0:         if (l.length > 5)
michael@0:           break;
michael@0:       }
michael@0:     }
michael@0:     return l;
michael@0:   }
michael@0: };