`@api_view` decorator does not provide access to all classes

[qqii]

It does not support content_negotiation_class, metadata_class and versioning_class.

[browniebroke]

Good point. What is your use case you encountered they were lacking?

At first glance, it feels borderline a new feature and there is an easy workaround (use a class based view), so I didn't think we'll implement it.

However, upon closer inspection, the default API settings (DEFAULT_CONTENT_NEGOTIATION_CLASS, DEFAULT_METADATA_CLASS, and DEFAULT_VERSIONING_CLASS) aren't honored for @api_view function based views:

django-rest-framework/rest_framework/decorators.py

Lines 58 to 74 in 74689b1

	WrappedAPIView.renderer_classes = getattr(func, 'renderer_classes',
	APIView.renderer_classes)
	WrappedAPIView.parser_classes = getattr(func, 'parser_classes',
	APIView.parser_classes)
	WrappedAPIView.authentication_classes = getattr(func, 'authentication_classes',
	APIView.authentication_classes)
	WrappedAPIView.throttle_classes = getattr(func, 'throttle_classes',
	APIView.throttle_classes)
	WrappedAPIView.permission_classes = getattr(func, 'permission_classes',
	APIView.permission_classes)
	WrappedAPIView.schema = getattr(func, 'schema',
	APIView.schema)

Reference:

• When metadata_class was added: f4b1dcb
• When versioning_class was added: 6e51e4f

[qqii]

The big one for me is versioning_class, which we find DRF's numerous options very welcome.

Yes, I also discovered that it didn't respect the override either so my existing workaround is to define the decorator

def versioning_class(versioning_class):
    def decorator(func):
        func.versioning_class = versioning_class
        return func
    return decorator

and an inlined version of api_view that supports it

def api_view(http_method_names=None):
    # ...
    def decorator(func):
        # ...
        WrappedAPIView.versioning_class = getattr(func, "versioning_class", APIView.versioning_class)
        # ...
    # ...

Would you consider this out of scope for a contribution?

[qqii]

Any thoughts @browniebroke, would you be against me opening a PR based on my branch?