Nested resources in Django REST Framework

Question

I wish to implement my new API with a nested resource.

Example: /api/users/:user_id/posts/

Will evaluate to all of the posts for a specific user. I haven't seen an working example for this use case, maybe this isn't the right way for implementing rest API?

Answer 1

As commented by Danilo, the @link decorator got removed in favor of @list_route and @detail_route decorators.

Update: @detail_route & @list_route got deprecated in favor of @action.

Here's the alternate solutions:

Solution 1:

@detail_route()
def posts(self, request, pk=None):
    owner = self.get_object()
    posts = Post.objects.filter(owner=owner)

    context = {
        'request': request
    }

    post_serializer = PostSerializer(posts, many=True, context=context)
    return Response(post_serializer.data)

Solution 2:

Try drf-nested-routers. Haven't tried this out yet, but looks promising, many are already using it. Looks like an advanced version of what we are already trying to achieve.

Hope this helps.

Answer 2

To map /api/users/:user_id/posts/ you can decorate a posts method inside your ViewSet with @link()

from rest_framework.decorators import link
from rest_framework.response import Response


class UserViewSet(viewsets.ModelViewSet):
    model = User
    serializer_class = UserSerializer
    
    # Your regular ModelViewSet things here

    # Add a decorated method like this
    @link()
    def posts(self, request, pk):
        # pk is the user_id in your example
            
        posts = Post.objects.filter(owner=pk)    
        
        # Or, you can also do a related objects query, something like:
        # user = self.get_object(pk)
        # posts = user.post_set.all()

        # Then just serialize and return it!
        serializer = PostSerializer(posts)
        return Response(serializer.data)

    

Answer 3

As commented by Danilo Cabello earlier you would use @detail_route or @list_route instead of @link(). Please read the documentation for "Routers", section "Extra link and actions" and "ViewSets", section "Marking extra actions for routing" for detailed explanations.