README.md

Nested ViewSets for DRF

DRF doesn't allow nested ViewSets natively, so I figured out the least amount of tweaks required to get it working.

The fields that are provided allow you to override the reverse() call with a specific mapping. These cannot be used across urls yet, as it pulls straight from the kwargs.

In your field, you must define map, which is a dictionary of destinaton => previous kwargs keys. These keys are relative to the current URL.

fields.py

from rest_framework.serializers import HyperlinkedIdentityField, \
HyperlinkedRelatedField


class NestedHyperlinkedField(object):
    
    base_obj = None
    
    def __init__(self, *args, **kwargs):
        self.map = kwargs.pop("map", {})
        
        super(NestedHyperlinkedField, self).__init__(*args, **kwargs)
    
    def field_to_native(self, obj, field_name):
        import logging
        
        self.base_obj = obj
        
        return super(NestedHyperlinkedField, self).field_to_native(obj,
                                                                   field_name)
    
    def get_url(self, obj, view_name, request, format):
        from django.core.urlresolvers import NoReverseMatch
        from rest_framework.reverse import reverse
        import logging
        
        try:
            return super(NestedHyperlinkedField, self).get_url(obj,
                view_name, request, format)
        except NoReverseMatch:
            pass
        
        kwargs = {
            "pk": obj.pk,
        }
        
        serializer = self.parent
        view = serializer.context["view"]
        
        for key, kwkey in self.map.iteritems():
            base_obj = self.base_obj.pk if self.base_obj else 0
            kwargs[key] = view.kwargs.get(kwkey, base_obj)
        
        url = reverse(view_name, kwargs=kwargs, request=request, format=format)
        
        return url


class HyperlinkedIdentityField(NestedHyperlinkedField,
                               HyperlinkedIdentityField):
    pass


class HyperlinkedRelatedField(NestedHyperlinkedField, HyperlinkedRelatedField):
    pass

router.py

class ApiRouter(routers.DefaultRouter):
    
    def get_api_root_view(self):
        """
        Return a view to use as the API root.
        """
        
        from django.core.urlresolvers import NoReverseMatch
        from rest_framework import views
        
        api_root_dict = {}
        list_name = self.routes[0].name
        for prefix, viewset, basename in self.registry:
            api_root_dict[prefix] = list_name.format(basename=basename)

        class APIRoot(views.APIView):
            _ignore_model_permissions = True

            def get(self, request, format=None):
                ret = {}
                for key, url_name in api_root_dict.items():
                    try:
                        ret[key] = reverse(url_name, request=request, format=format)
                    except NoReverseMatch:
                        pass
                return Response(ret)

        return APIRoot.as_view()