ResourceRelatedField.source doesn't allow nested paths

[SafaAlfulaij]

Compared to how DRF allow nested paths in source:
https://github.com/encode/django-rest-framework/blob/master/rest_framework/fields.py#L401

DJA doesn't allow it:

django-rest-framework-json-api/rest_framework_json_api/utils.py

Line 204 in 51daed1

parent_model_relation = getattr(parent_model, relation.source)

Examples here: https://www.django-rest-framework.org/api-guide/fields/#source
EmailField(source='user.email')

[sliverc]

As far as I see does this only affect ResourceRelatedField for all other serializer fields dotted source should work.

I wonder why relation.get_attribute(model) is not used there which should solve this issue.

[bashlyss]

I'm not sure if this issue still applies in full in the current version. In my own testing of both fk, 1:1 and m2m relationships, only nested m2m fields had any issue. #1065 opened as a fix to this case