Problem images loaded from cache after moving/resizing the problem widget
It is currently allowed to move problems after an exam is finalized and submissions are already uploaded. However, the images for each problem are cached in the browser. Thus after moving a problem, the corresponding image is not updated from the server but instead loaded from the cache.
A quick and dirty solution would be to just add some hash based on the widget position and size to the URL of each image in the front-end, like api/images/solutions/2/5/2/0?1234567890abcdef
, so the browser will load it again. Is this solution 'good enough' or should we take a more thorough look at caching in general?
Also related is #269 (closed).