Use postMessage to communicate between the iframe and TinyMCE.

This gets around cross-origin issues on the CDN.

Delete plugin.min.js as the Jake command will minimize into the full file.

common/lib/xmodule/xmodule/js/src/html/edit.coffee

@@ -63,8 +63,8 @@ class @HTMLEditingDescriptor
     ed.on('EditImage', @editImage)
     ed.on('SaveLink', @saveLink)
     ed.on('EditLink', @editLink)
-    ed.on('ShowCodeMirror', @showCodeEditor)
-    ed.on('SaveCodeMirror', @saveCodeEditor)
+    ed.on('ShowCodeEditor', @showCodeEditor)
+    ed.on('SaveCodeEditor', @saveCodeEditor)
 
   editImage: (data) =>
     # Called when the image plugin will be shown. Input arg is the JSON version of the image data.
@@ -86,17 +86,17 @@ class @HTMLEditingDescriptor
     if data['href']
       data['href'] = rewriteStaticLinks(data['href'], '/static/', @base_asset_url)
 
-  showCodeEditor: (codeEditor) =>
+  showCodeEditor: (source) =>
     # Called when the CodeMirror Editor is displayed to convert links to show static prefix.
-    # The input argument is the CodeMirror instance.
-    content = rewriteStaticLinks(codeEditor.getValue(), @base_asset_url, '/static/')
-    codeEditor.setValue(content)
+    # The input argument is a dict with the text content.
+    content = rewriteStaticLinks(source.content, @base_asset_url, '/static/')
+    source.content = content
 
-  saveCodeEditor: (codeEditor) =>
+  saveCodeEditor: (source) =>
     # Called when the CodeMirror Editor is saved to convert links back to the full form.
-    # The input argument is the CodeMirror instance.
-    content = rewriteStaticLinks(codeEditor.getValue(), '/static/', @base_asset_url)
-    codeEditor.setValue(content)
+    # The input argument is a dict with the text content.
+    content = rewriteStaticLinks(source.content, '/static/', @base_asset_url)
+    source.content = content
 
   initInstanceCallback: (visualEditor) =>
     visualEditor.setContent(rewriteStaticLinks(visualEditor.getContent({no_events: 1}), '/static/', @base_asset_url))

common/static/js/vendor/tiny_mce/plugins/codemirror/plugin.js

@@ -18,24 +18,114 @@ tinymce.PluginManager.add('codemirror', function(editor, url) {
 		editor.selection.collapse(true);
 		editor.selection.setContent('<span class="CmCaReT" style="display:none">&#0;</span>');
 
+        // Determine the origin of the window that will host the code editor.
+        // If tinyMCE's baseURL is relative, then static files are hosted in the
+        // same origin as the containing page. If it is not relative, then we know that
+        // the origin of the iframe hosting the code editor will match the origin
+        // of tinyMCE's baseURL, as they are both hosted on the CDN.
+        var codeEditorOrigin;
+        var index = tinyMCE.baseURL.indexOf("/static/");
+        if (index > 0) {
+            codeEditorOrigin = tinyMCE.baseURL.substring(0, index);
+        }
+        else {
+            codeEditorOrigin = window.location.origin;
+        }
+
+        // Send the path location for CodeMirror and the parent origin to use in postMessage.
+        var sourceHtmlParams = "?CodeMirrorPath=" + editor.settings.codemirror.path +
+            "&ParentOrigin=" + window.location.origin;
+
 		// Open editor window
 		var win = editor.windowManager.open({
 			title: 'HTML source code',
-			url: url + '/source.html',
-			width: 800,
-			height: 550,
-			resizable : true,
-			maximizable : true,
-			buttons: [
-				{ text: 'Ok', subtype: 'primary', onclick: function(){
-					var doc = document.querySelectorAll('.mce-container-body>iframe')[0];
-					doc.contentWindow.submit();
-					win.close();
-				}},
-				{ text: 'Cancel', onclick: 'close' }
-			]
-		});
-	};
+            url: url + '/source.html' + sourceHtmlParams,
+            width: 800,
+            height: 550,
+            resizable: true,
+            maximizable: true,
+            buttons: [
+                { text: 'OK', subtype: 'primary', onclick: function () {
+                    postToCodeEditor({type: "save"});
+                }},
+                { text: 'Cancel', onclick: function () {
+                    postToCodeEditor({type: "cancel"});
+                }}
+            ]
+
+        });
+
+        // The master version of TinyMCE has a win.getContentWindow() method. This is its implementation.
+        var codeWindow = win.getEl().getElementsByTagName('iframe')[0].contentWindow;
+
+        var postToCodeEditor = function (data) {
+            codeWindow.postMessage(data, codeEditorOrigin);
+        };
+
+        var messageListener = function (event) {
+            // Check that the message came from the code editor.
+            if (codeEditorOrigin !== event.origin) {
+                return;
+            }
+
+            var source;
+            if (event.data.type === "init") {
+                source = {content: editor.getContent({source_view: true})};
+                // Post an event to allow rewriting of static links on the content.
+                editor.fire("ShowCodeEditor", source);
+
+                postToCodeEditor(
+                    {
+                        type: "init",
+                        content: source.content
+                    }
+                );
+                editor.dom.remove(editor.dom.select('.CmCaReT'));
+            }
+            else if (event.data.type === "setText") {
+                source = {content: event.data.text};
+                var isDirty = event.data.isDirty;
+
+                // Post an event to allow rewriting of static links on the content.
+                editor.fire('SaveCodeEditor', source);
+
+                editor.setContent(source.content);
+
+                // Set cursor:
+                var el = editor.dom.select('span#CmCaReT')[0];
+                if (el) {
+                    editor.selection.scrollIntoView(el);
+                    editor.selection.setCursorLocation(el,0);
+                    editor.dom.remove(el);
+                }
+                // EDX: added because CmCaReT span was getting left in when caret was within a style tag.
+                // Make sure to strip it out (and accept that caret will not be in the correct place).
+                else {
+                    var content = editor.getContent();
+                    var strippedContent = content.replace('<span id="CmCaReT"></span>', '');
+                    if (content !== strippedContent) {
+                        editor.setContent(strippedContent);
+                    }
+                }
+
+                // EDX: moved block of code from original location since we may change content in bug fix code above.
+                editor.isNotDirty = !isDirty;
+                if (isDirty) {
+                    editor.nodeChanged();
+                }
+            }
+            else if (event.data.type === "closeWindow") {
+                win.close();
+            }
+        };
+
+        win.on("close", function() {
+            window.removeEventListener("message", messageListener);
+        });
+
+        window.addEventListener("message", messageListener, false);
+
+	}
 
 	// Add a button to the button bar
     // EDX changed to show "HTML" on toolbar button