Address review comments.

vectordraw/public/js/studio_edit.js

@@ -4,6 +4,7 @@ function StudioEditableXBlockMixin(runtime, element) {
 
     var fields = [];
     var tinyMceAvailable = (typeof $.fn.tinymce !== 'undefined'); // Studio includes a copy of tinyMCE and its jQuery plugin
+    var errorMessage = gettext("This may be happening because of an error with our server or your internet connection. Try refreshing the page or making sure you are online.");
 
     $(element).find('.field-data-control').each(function() {
         var $field = $(this);
@@ -71,20 +72,20 @@ function StudioEditableXBlockMixin(runtime, element) {
             url: handlerUrl,
             data: JSON.stringify(data),
             dataType: "json",
-            global: false,  // Disable Studio's error handling that conflicts with studio's notify('save') and notify('cancel') :-/
-            success: function(response) { runtime.notify('save', {state: 'end'}); }
+            global: false  // Disable Studio's error handling that conflicts with studio's notify('save') and notify('cancel') :-/
+        }).done(function(response) {
+            runtime.notify('save', {state: 'end'});
         }).fail(function(jqXHR) {
-            var message = gettext("This may be happening because of an error with our server or your internet connection. Try refreshing the page or making sure you are online.");
             if (jqXHR.responseText) { // Is there a more specific error message we can show?
                 try {
-                    message = JSON.parse(jqXHR.responseText).error;
-                    if (typeof message === "object" && message.messages) {
+                    errorMessage = JSON.parse(jqXHR.responseText).error;
+                    if (typeof errorMessage === "object" && errorMessage.messages) {
                         // e.g. {"error": {"messages": [{"text": "Unknown user 'bob'!", "type": "error"}, ...]}} etc.
-                        message = $.map(message.messages, function(msg) { return msg.text; }).join(", ");
+                        errorMessage = $.map(errorMessage.messages, function(msg) { return msg.text; }).join(", ");
                     }
-                } catch (error) { message = jqXHR.responseText.substr(0, 300); }
+                } catch (error) { errorMessage = jqXHR.responseText.substr(0, 300); }
             }
-            runtime.notify('error', {title: gettext("Unable to update settings"), message: message});
+            runtime.notify('error', {title: gettext("Unable to update settings"), message: errorMessage});
         });
     };
 

vectordraw/templates/html/vectordraw_edit.html

@@ -68,12 +68,15 @@
 
           <p id="wysiwyg-description">
             {% blocktrans %}
-            Use the board below to define a set of working vectors for this exercise.
+            Instead of using the "Vectors" field above to define or modify
+            the set of working vectors for this exercise, you can also use the board below.
             To add a vector, left-click the board where you want the vector to originate.
             Keep holding down the left mouse button and drag your mouse pointer across the board
             to achieve the desired length and angle for the vector.
             To modify an existing vector, left-click it, hold down the left mouse button,
             and move your mouse pointer across the board.
+            Note that if you make changes using the board below, any changes you made via the "Vectors" field above
+            will be overwritten when you save the settings for this exercise by clicking the "Save" button below.
             {% endblocktrans %}
           </p>
 

vectordraw/vectordraw.py

@@ -139,8 +139,9 @@ class VectorDrawXBlock(StudioEditableXBlockMixin, XBlock):
             "List of vectors to use for the exercise. "
             "You must specify it as an array of entries "
             "where each entry represents an individual vector. "
-            "Note that edits to vectors made via the WYSIWYG editor below "
-            "take precedence over changes you make here when saving."
+            "Note that you can also use the WYSIWYG editor below to create or modify vectors. "
+            "If you do, any changes you make here will be overwritten by vector data "
+            "from the WYSIWYG editor when saving."
         ),
         default="[]",
         multiline_editor=True,