Overriding the Algorithm

There are services that you can override to change the way the framework determines where to store the files. The default implementation is usually sufficient, but you can override it if you need to.

File Location Resolver

To override the general algorithm that determines where to store the files, you can create your own implementation of ClassBasedFileLocationResolverInterface. It takes the class name of the object, the ID, and the property name; then returns a FilePointerInterface.

For an example, see the class DefaultClassBasedFileLocationResolver.

Object ID Resolver

ClassBasedFileLocationResolverInterface takes the object's ID as a string. To determine the ID, the framework uses ObjectIdResolverInterface.

You can create an ObjectIdResolverInterface if you need to override how the framework obtains an object's identifier. This is usually only necessary if your object's ID cannot be serialized to string, which should never happen in practice.

Class Signature Resolver

The framework calls ClassSignatureResolverInterface to convert the class name into its signature. This is done so that the class name does not appear in the file path. The default implementation is DefaultClassSignatureResolver which converts the class name into its SHA-1 hash.

Also available is AttributeClassSignatureResolver, it looks for the WithFileAssociation attribute on the class and uses the value of its argument as the class signature. This is useful if you are renaming a class as it would result in a different SHA-1 hash, and the framework would not be able to find previously stored files.

Manual Service Configuration

If you are not using autoconfiguration, you have to tag the services you created in the service container. Example:

services:
    App\MyClassBasedFileLocationResolver:
        tags:
            - { name: 'rekalogika.file.association.class_based_file_location_resolver' }

    App\MyObjectIdResolver:
        tags:
            - { name: 'rekalogika.file.association.object_id_resolver' }

    App\MyClassSignatureResolver:
        tags:
            - { name: 'rekalogika.file.association.class_signature_resolver' }