On Tue, Sep 6, 2011 at 7:05 AM, Daniel Barrett <[email protected]> wrote:
> The most frequent problem on our wiki (MediaWiki 1.17.0) involves > re-uploads of images, where users are fooled by browser caching: > > 1. A user uploads a modified version of an existing image > (File:Foobar.jpg) > 2. After the upload, user views File:Foobar.jpg but the old image is > still showing. > 3. User tries uploading 10 more times. The old image is still showing. > 4. User calls tech support, who says, "press ctrl-F5 to refresh your > browser." > 5. User presses ctrl-F5 and the new image shows up. > > Obviously the problem is due to browser caching. Is there any way for the > MediaWiki software to prevent this problem from happening and show only > uncached images on File:Foobar.jpg? The average user doesn't know anything > about browser caching. > Couple things to try: 1) Change your web server configuration to send a Cache-Control header telling browsers to double-check all files in your image uploads directory, like: Cache-Control: public, must-validate This may make images load slightly more slowly, but should still make use of the cache -- images should be re-checked on every page load but only actually re-downloaded when they change. 2) Try to figure out what bit of code makes the actual view URLs (including thumbnails) and append a timestamp in a query string to make it a distinct URL for each upload version. Not sure how convenient this is... possible MediaTransformOutput::toHtml(), or perhaps in whatever sticks a URL into the MediaTransformOutput object? Meh. :) Note there have been vague plans on the table for some years to restructure image storage in a way that gives a unique URL for each version of a file (bypassing this problem and also merging storage of duplicate files) but we only ever got it implemented for deleted files. -- brion _______________________________________________ MediaWiki-l mailing list [email protected] https://lists.wikimedia.org/mailman/listinfo/mediawiki-l
