Caching issue with annotations in feedback player

[fosterfarrell9]

In production, I experienced the following issue with annotations: A student had made an annotation in a video, and that annotation was shared with me. I noticed the anotation when I opened the feedback player. Then I went through the other videos of my lecture and was puzzled to see the exact same annotation in all of them, always at the same time (when it did not make any contextual sense). It turned out that the annotation vanished in the feedback player when I did a page "shift reload". After that I opened the feedback player for the video that actually contained the annotation and noticed that it had been gone. A "shift reload" of the page made it reappear. Apparently, there are some caching issues here. I can reproduce the behaviour in development.

[fosterfarrell9]

I played around locally a bit in order to get a feeling for what is going on. It seems that the problem appears when you make use of the browser's Back-button (while seems not to appear when you separately open different feedback players in different tabs). In the case where annotations are displayed that belong to a video from before in the browsing history, no update_annotations action is triggered. All of this leads me to suspect that turbolinks is what causes the problems.

[Splines]

I made a fix for this that might have fixed it, but I'm not entirely sure. Could you check that this bug does not occur anymore in production?

[fosterfarrell9]

Seems to work fine now.