Update file paths in content when media file is replaced

[timobrembeck]

Describe the Bug

At the moment, we keep the file path identical when we're replacing media files.
This has the disadvantage that the app needs to download the files again to check whether it has changed. It would be more efficient if we treat filenames more like unique ids of files and change them in the content when they are replaced.

Steps to Reproduce

1. Insert media file into content of page
2. Replace file in media library
3. Refresh preview of page
4. Even though the timestamp in the media library itself is updated, the content remains the same.

Expected Behavior

When a media file is replaced in the media library, the new image should also be shown in the apps.

We can use the Link model of the linkcheck app to get the mapping between media files and page translations which contain the file. Then, we can update the url in the content.

Actual Behavior

Since the file path doesn't change, it is cached at the moment

Additional Information

Related issues:

• Add a region link replacement function #1851

[osmers]

Referring here to issue #1742 - it would still be helpful to have an updated and an original date, so that I know that the file has been updated - it if is not too much hassle

[steffenkleinle]

Could you notify the app team in this issue once this is done please? Thanks :)

[sarahsporck]

I'm wondering what makes most sense here. Currently files are stored like this: {subdirectory}/{strftime('%Y/%m')}/{filename} and the new (replacing) file only modifies certain attributes of the media_file.

• upload the new file at e.g. {subdirectory}/{int(time())}/{filename}
• delete the old file at the other path

Am I missing something? :)

[timobrembeck]

Hmm, I guess I would stick with the year/month naming scheme instead of int(time()), so maybe it would already suffice to just remove the following lines?

integreat-cms/integreat_cms/cms/models/media/media_file.py

Lines 46 to 55 in cd9508f

	# If the instance already exists in the database, make sure the upload path doesn't change
	if instance.id:
	original_instance = MediaFile.objects.get(id=instance.id)
	if original_instance.file:
	logger.debug(
	"%r already exists in the database, keeping original upload path: %r",
	instance,
	original_instance.file.name,
	)
	return original_instance.file.name

And I think Django does not automatically delete the old file, yes so we'd have to do that manually.
And after that, we need to do a search & replace of the paths in the whole content to make sure we don't get a bunch of 404 errors on the old file path.

[sarahsporck]

Thank you for the hint. Was a little bit stuck here.