Document how to share filter sets with multiple data loaders

[tacman]

I have several data loaders in flysystem. In the liip configuration, I can either set the default data loader for all filter sets, OR set a data loader within each filterset.

But I want to apply the same filter to multiple sets.

    loaders:
        flysystem_loader:
            flysystem:
                # this comes from flysystem.yaml
                filesystem_service: default.storage

    # default loader to use for all filter sets
    data_loader: flysystem_loader
    filter_sets:
        auto_rotate: ~
        large_s3:
            data_loader: s3.storage
            filters:
                thumbnail:
                    size:          [400, 400]
                    allow_upscale: true
                    mode: inset
        large:
            filters:
                thumbnail:
                    size:          [400, 400]
                    allow_upscale: true
                    mode: inset

in flysystem

flysystem:
    storages:
        default.storage:
            adapter: 'local'
            options:
                directory: '%kernel.project_dir%/src'
        uploads.storage:
            adapter: 'local'
            options:
                 directory: '%kernel.project_dir%/private/uploads'
        s3.storage:
            adapter: 'aws'
            options:
                client: 'Aws\S3\S3Client' # The service ID of the Aws\S3\S3Client instance,
                bucket: '%env(AWS_S3_BUCKET_NAME)%'
                streamReads: true
                prefix: '%env(S3_STORAGE_PREFIX)%'

I know which flysystemOperator I have, I want to pass it into the imagine_filter filter in twig, and the cache->getBrowserPath() method in php, but there seems to be no way to indicate which datasource.

I see I can use a chain loader, but that could get expensive if I have multiple could-based loaders and it has to loop through them to find the right one.

Thoughts on how this might be done?

[dbu]

i think you could use yaml overrides, see for example https://www.linode.com/docs/guides/yaml-anchors-aliases-overrides-extensions/#yaml-overrides . its basically a copy-paste instruction for the yaml parser. symfony supports this feature.