Breaking: #101948 - File-based AbstractRepository class removed

See forge#101948

Description

When the base architecture of File Abstraction Layer (FAL) was introduced in TYPO3 v6.0, various functionality was based on concepts based on Extbase's architecture. Some concepts never flourished. One of them being the TYPO3\CMS\Core\Resource\AbstractRepository class from FAL.

This PHP class served as a basis for 2 PHP classes, TYPO3\CMS\Core\Resource\FileRepository and TYPO3\CMS\Core\Resource\ProcessedFileRepository.

Nowadays, it is obvious that some decisions in this area were not useful:

1. The coupling to Extbase's Repository architecture does not work out, as the manual database queries that return objects should not be bound to Extbase's QueryRestrictions.

These never worked and were never implemented in the mentioned Repository classes from FAL.

It becomes abundantly clear that the concepts do not match by looking at the AbstractRepository class which even had exceptions for methods that were not compatible with Extbase.

2. The concept of inheritance did not work out for Dependency Injection introduced in TYPO3 v10, and with PHP 8.x which reveals various typing problems that arose around AbstractRepository.

AbstractRepository is thus removed, and the implementing classes do not extend from this class anymore, as they only include the methods required for their purpose, and are now completely strictly typed.

Impact

Code that uses the three classes in a third-party extension might fail as the implementing PHP repositories FileRepository and ProcessedFileRepository have only necessary methods available.

PHP extensions that derive from the AbstractRepository will stop working.

Affected installations

As all three PHP classes are low-level in the FAL API, the impact for regular installations will be rather low. Third-party extensions that extend from the AbstractRepository of FAL, which is a wild use-case will stop working. It is safe to say, that only edge-case extensions that worked with the FAL API might be affected, but regular installations will see no difference.

Migration

Only extension authors working with the low-level API of File Abstraction Layer would need to adapt their code to be type-safe. Extensions that extend from the AbstractRepository class of FAL should implement the necessary methods themselves and remove the dependency from AbstractRepository.

It is highly recommended to not use any of these classes, but rather stick to high-level API of FAL, such as ResourceFactory, File or ResourceStorage.