'HyperlinkedModelSerializer' with custom nested 'view_name's does not work in combination with 'depth'

[stephenfin]

Checklist

• I have verified that that issue exists against the master branch of Django REST framework.
• I have searched for similar issues in both open and closed tickets and cannot find a duplicate.
• This is not a usage question. (Those should be directed to the discussion group instead.)
• This cannot be dealt with as a third party library. (We prefer new functionality to be in the form of third party libraries where possible.)
• I have reduced the issue to the simplest possible case.
• I have included a failing test as a pull request. (If you are unable to do so we can still accept the issue.)

Steps to reproduce

I have a number of HyperlinkedModelSerializers. As I'm using manual URL definition, rather than a router, I must manually specify the view_name for each nested resource as part of extra_kwargs.

class BookSerializer(HyperlinkedModelSerializer):

    class Meta:
        model = Book
        fields = ('id', 'url', 'author')
        read_only_fields = fields
        extra_kwargs = {
            'url': {'view_name': 'api-book-detail'},
            'author': {'view_name': 'api-person-detail'},
        }

This will result in an output like so:

{
    "id": 1,
    "url": "http://example.com/api/v1/books/1",
    "author": "http://example.com/api/v1/authors/1"
}

This took me a while to figure out but pretty much works as expected. However, I now wish to provide a little more detail in response by nesting real objects in the response. It would appear that the depth meta key is the correct way to do this, like so:

class BookSerializer(HyperlinkedModelSerializer):

    class Meta:
        model = Book
        fields = ('id', 'url', 'author')
        read_only_fields = fields
        depth = 1
        extra_kwargs = {
            'url': {'view_name': 'api-book-detail'},
            'author': {'view_name': 'api-author-detail'},
        }

However, this fails.

Expected behavior

I would expect to see a nested response like so:

{
    "id": 1,
    "url": "http://example.com/api/v1/books/1",
    "author": {
        "id": 1,
        "url": "http://example.com/api/v1/authors/1",
        "name": "John Doe",
        "user": "http://example.com/api/v1/users/1"
     }
}

Actual behavior

I get an exception like so:

TypeError: __init__() got an unexpected keyword argument 'view_name'

If I remove the author field from extra_kwargs, this changes to:

django.core.exceptions.ImproperlyConfigured: Could not resolve URL for hyperlinked relationship using view name "author-detail". You may have failed to include the related model in your API, or incorrectly configured the `lookup_field` attribute on this field.

Seeing as these two features work independently, I can't see why they wouldn't work together.

[lovelydinosaur]

You'd need to set the view_name on a nested author serializer, for both the url and user fields.

[TZanke]

This is correct, but to declare view_name in a sub serializer i have to set the nested serializer explicitly in the first serializer. But this disables the depth logic to hyperlink OR nest a sub serializer depending on the depth attribute.

How to define the sub serializer class without setting the nested serializer explicitly? Is it possible with extra_kwargs?!

In the example of @stephenfin Django Rest Framework never knows if there exists a custom author serializer (which would define a view_name per field). It just knows the view_name url, which is a unkown argument for the dynamic NestedSerializer in https://github.com/encode/django-rest-framework/blob/master/rest_framework/serializers.py#L1563