TYPO3 Core

Having this change integrated it would also be possible to add custom field to FileReferences and then get them handled from within any slot attaching to the "emitPreProcessFile" signal.

Maybe we can have another look at this when we proceed with #54229

#54229 seems something REALLY required.

The current file processing mechanism is mostly unflexible.

For example it is almost impossible to process a file twice.

I used the "preProcess" slot of the FileProcessingService to hook in a custom method. Altough I already modified (overridden) the ImageService class of extbase to pass along the FileReference it seemed almost impossible to process a file two times. Reason:

When a file gets processed it will be put under the processed folder of its storage. When you then need to process the file again it is not possible to retrieve a "Resource\File" object for the processed file by any means (Except large scale xclassing). The ResourceFactory methods for retrieving a file will always return a "ProcessedFile" instance instead.

So for processing the file again I had to create a second Resource-Storage record and have it assigned a different processed folder (alt_processed). Then I could request my alternative Resource-Storage for the already processed file and got a Resource\File object back which I could then process again (and having the result put in _alt_processed).