Merge pull request #12275 from edx/ormsbee/video_state_opt_2

Remove unnecessary VideoModule save_states.

common/lib/xmodule/xmodule/js/spec/video/video_save_state_plugin_spec.js

@@ -9,12 +9,14 @@
                 .createSpy('onTouchBasedDevice')
                 .and.returnValue(null);
 
-            state = jasmine.initializePlayer();
+            state = jasmine.initializePlayer({
+                recordedYoutubeIsAvailable: true
+            });
             spyOn(state.storage, 'setItem');
         });
 
         afterEach(function () {
-            
+
             $('source').remove();
             window.onTouchBasedDevice = oldOTBD;
             state.storage.clear();
@@ -199,7 +201,20 @@
             expect(state.storage.setItem).toHaveBeenCalledWith('language', 'ua');
         });
 
-        it('can save information about youtube availability', function () {
+        it('can save youtube availability', function () {
+            $.ajax.calls.reset();
+
+            // Test the cases where we shouldn't send anything at all -- client
+            // side code determines that YouTube availability is the same as
+            // what's already been recorded on the server side.
+            state.config.recordedYoutubeIsAvailable = true;
+            state.el.trigger('youtube_availability', [true]);
+            state.config.recordedYoutubeIsAvailable = false;
+            state.el.trigger('youtube_availability', [false]);
+            expect($.ajax).not.toHaveBeenCalled();
+
+            // Test that we can go from unavailable -> available
+            state.config.recordedYoutubeIsAvailable = false;
             state.el.trigger('youtube_availability', [true]);
             expect($.ajax).toHaveBeenCalledWith({
                 url: state.config.saveStateUrl,
@@ -208,6 +223,17 @@
                 dataType: 'json',
                 data: {youtube_is_available: true}
             });
+
+             // Test that we can go from available -> unavailable
+            state.config.recordedYoutubeIsAvailable = true;
+            state.el.trigger('youtube_availability', [false]);
+            expect($.ajax).toHaveBeenCalledWith({
+                url: state.config.saveStateUrl,
+                type: 'POST',
+                async: true,
+                dataType: 'json',
+                data: {youtube_is_available: false}
+            });
         });
 
         it('can destroy itself', function () {

common/lib/xmodule/xmodule/js/src/video/09_save_state_plugin.js

@@ -84,7 +84,12 @@ define('video/09_save_state_plugin.js', [], function() {
         },
 
         onYoutubeAvailability: function (event, youtubeIsAvailable) {
-            this.saveState(true, {youtube_is_available: youtubeIsAvailable});
+            // Compare what the client-side code has determined Youtube
+            // availability to be (true/false) vs. what the LMS recorded for
+            // this user. The LMS will assume YouTube is available by default.
+            if (youtubeIsAvailable !== this.state.config.recordedYoutubeIsAvailable) {
+                this.saveState(true, {youtube_is_available: youtubeIsAvailable});
+            }
         },
 
         saveState: function (async, data) {

common/lib/xmodule/xmodule/video_module/video_module.py

@@ -332,7 +332,12 @@ class VideoModule(VideoFields, VideoTranscriptsMixin, VideoStudentViewHandlers,
             ## There is no option in the "Advanced Editor" to set this option. However,
             ## this option will have an effect if changed to "True". The code on
             ## front-end exists.
-            'autohideHtml5': False
+            'autohideHtml5': False,
+
+            # This is the server's guess at whether youtube is available for
+            # this user, based on what was recorded the last time we saw the
+            # user, and defaulting to True.
+            'recordedYoutubeIsAvailable': self.youtube_is_available,
         }
 
         bumperize(self)