My nodes of content type Article contain an entity reference to Audio media. This Audio media has a file entity reference.
When listing articles via JSON:API, I want to automatically include this file entity reference for any articles that have it.
To auto-include the Audio media entity reference, I can use the JSON:API Defaults submodule of the JSON:API Extras module to add
audioMedia (JSON:API Extras customized name for the entity reference field pointing to Audio media).
However, I don't know how to auto-include the file entity reference, which is on the
audioMedia entity reference.
I tried customizing the Audio media resource to include the file reference, but that includes it when accessing Audio media via JSON:API, not when accessing Articles.
I also tried adding
file to the Default include list for Articles, but this gives an error that
file is not an available option.
So how can I auto-include the entity reference of an entity reference with JSON:API Defaults?