Allow web translators to monitor DOM nodes for changes in order to re-trigger detectWeb

chrome/content/zotero/browser.js

@@ -46,6 +46,7 @@ var Zotero_Browser = new function() {
 	this.toggleCollapsed = toggleCollapsed;
 	this.chromeLoad = chromeLoad;
 	this.contentLoad = contentLoad;
+	this.itemUpdated = itemUpdated;
 	this.contentHide = contentHide;
 	this.tabClose = tabClose;
 	this.resize = resize;
@@ -344,7 +345,7 @@ var Zotero_Browser = new function() {
 		if(isHTML) {
 			var contentWin = doc.defaultView;
 			if(!contentWin.haveZoteroEventListener) {
-				contentWin.addEventListener("ZoteroItemUpdated", itemUpdated, false);
+				contentWin.addEventListener("ZoteroItemUpdated", function(event) { itemUpdated(event.originalTarget) }, false);
 				contentWin.haveZoteroEventListener = true;
 			}
 		}
@@ -380,14 +381,13 @@ var Zotero_Browser = new function() {
 	/**
 	 * Called when item should be updated due to a DOM event
 	 */
-	function itemUpdated(event) {
+	function itemUpdated(doc) {
 		try {
-		var doc = event.originalTarget;
+			var rootDoc = (doc instanceof HTMLDocument ? doc.defaultView.top.document : doc);
-		var rootDoc = (doc instanceof HTMLDocument ? doc.defaultView.top.document : doc);
+			var browser = Zotero_Browser.tabbrowser.getBrowserForDocument(rootDoc);
-		var browser = Zotero_Browser.tabbrowser.getBrowserForDocument(rootDoc);
+			var tab = _getTabObject(browser);
-		var tab = _getTabObject(browser);
+			if(doc == tab.page.document || doc == rootDoc) tab.clear();
-		if(doc == tab.page.document || doc == rootDoc) tab.clear();
+			tab.detectTranslators(rootDoc, doc);
-		tab.detectTranslators(rootDoc, doc);
 		} catch(e) {
 			Zotero.debug(e);
 		}
@@ -649,6 +649,7 @@ Zotero_Browser.Tab.prototype.detectTranslators = function(rootDoc, doc) {
 		var translate = new Zotero.Translate.Web();
 		translate.setDocument(doc);
 		translate.setHandler("translators", function(obj, item) { me._translatorsAvailable(obj, item) });
+		translate.setHandler("pageModified", function(translate, doc) { Zotero_Browser.itemUpdated(doc) });
 		translate.getTranslators(true);
 	} else if(doc.documentURI.substr(0, 7) == "file://") {
 		this._attemptLocalFileImport(doc);

chrome/content/zotero/xpcom/translation/translate.js

@@ -635,6 +635,52 @@ Zotero.Translate.Sandbox = {
 			
 			// call super
 			Zotero.Translate.Sandbox.Base._itemDone(translate, item);
+		},
+		
+		/**
+		 * Tells Zotero to monitor changes to the DOM and re-trigger detectWeb
+		 * Can only be set during the detectWeb call
+		 * @param {DOMNode} target Document node to monitor for changes
+		 * @param {MutationObserverInit} [config] specifies which DOM mutations should be reported
+		 */
+		"monitorDOMChanges":function(translate, target, config) {
+			if(translate._currentState != "detect") {
+				Zotero.debug("Translate: monitorDOMChanges can only be called during the 'detect' stage");
+				return;
+			}
+
+			var window = translate.document.defaultView
+			var mutationObserver = window && ( window.MutationObserver || window.WebKitMutationObserver || window.MozMutationObserver );
+			if(!mutationObserver) {
+				Zotero.debug("Translate: This browser does not support mutation observers.");
+				return;
+			}
+
+			var translator = translate._potentialTranslators[0];
+			if(!translate._registeredDOMObservers[translator.translatorID])
+				translate._registeredDOMObservers[translator.translatorID] = [];
+			var obs = translate._registeredDOMObservers[translator.translatorID];
+
+			//do not re-register observer by the same translator for the same node
+			if(obs.indexOf(target) != -1) {
+				Zotero.debug("Translate: Already monitoring this node");
+				return;
+			}
+
+			obs.push(target);
+
+			var observer = new mutationObserver(function(mutations, observer) {
+				obs.splice(obs.indexOf(target),1);
+				observer.disconnect();
+				
+				Zotero.debug("Translate: Page modified.");
+				//we don't really care what got updated
+				var doc = mutations[0].target.ownerDocument;
+				translate._runHandler("pageModified", doc);
+			});
+
+			observer.observe(target, config || {childList: true, subtree: true});
+			Zotero.debug("Translate: Mutation observer registered on <" + target.nodeName + "> node");
 		}
 	},
 
@@ -843,6 +889,11 @@ Zotero.Translate.Base.prototype = {
 	 *           complete
 	 *   passed: an array of appropriate translators
 	 *   returns: N/A
+	 * pageModified
+	 *   valid: web
+	 *   called: when a web page has been modified
+	 *   passed: the document object for the modified page
+	 *   returns: N/A
 	 * @param {Function} handler Callback function. All handlers will be passed the current
 	 * translate instance as the first argument. The second argument is dependent on the handler.
 	 */
@@ -909,7 +960,7 @@ Zotero.Translate.Base.prototype = {
 		if(this._handlers[type]) {
 			// compile list of arguments
 			if(this._parentTranslator) {
-				// if there is a parent translator, make sure we don't the Zotero.Translate
+				// if there is a parent translator, make sure we don't pass the Zotero.Translate
 				// object, since it could open a security hole
 				var args = [null];
 			} else {
@@ -1528,6 +1579,7 @@ Zotero.Translate.Base.prototype = {
  *     this Translate instance.
  */
 Zotero.Translate.Web = function() {
+	this._registeredDOMObservers = {}
 	this.init();
 }
 Zotero.Translate.Web.prototype = new Zotero.Translate.Base();