Wrong thumbnail images for ddr-ajah-8

[gjost]

Collection files are video interviews. Access files were imported via access_path i.e. not generated by imagemagick from the videos. There was a mismatch between the images and their associated videos. The image files were fixed and republished, but the thumbnails have already been made and are not updating. sorl.thumbnail generates the hashed filenames from the filenames, geometry, and efx rather than the file contents, so the existing thumbnails are "stuck". sorl.thumbnail doesn't seem to have a way to clear particular images.

Proposed fix:

• Get thumbnail hashes from the HTML source
• Remove the files from the filesystem
• Delete image metadata from the sqlite database

[gjost]

sorl-thumbnail has no way to clear/clean individual thumbnails, so solved this by deleting the thumbnails manually:

• Loaded collection detail, objects list, and object detail pages.
• Get thumbnail hashes from HTML source.
• SQLite: delete records containing the hashes
• Filesystem: delete files from /var/www/ddrpublic/media/cache/

Biggest problem was that browsers cached the thumbnails aggressively and it was difficult to tell if the fix worked.

If we had a larger collection we'd probably have to write a script that used the API to get filenames and stuff.