API view returning { "detail": "Not found." },

Question

class User(models.Model):
    user_id = models.CharField(max_length=255, unique=True)
    mobile = models.CharField(max_length=12)
    first_name = models.CharField(max_length=200, null=True)
    last_name = models.CharField(max_length=200, null=True)
    profile_image = models.URLField(null=True)
    email = models.EmailField(null=True)
    posts = models.ManyToManyField('uploads.Posts', related_name='post_user')
    created_on = models.DateTimeField(default=timezone.localtime)
    updated_on = models.DateTimeField(default=timezone.localtime)
    is_deleted = models.BooleanField(default=False)

class Posts(models.Model):
    url = models.URLField(null=True)
    description = models.TextField()
    created_on = models.DateTimeField(default=timezone.localtime)
    updated_on = models.DateTimeField(default=timezone.localtime)
    is_deleted = models.BooleanField(default=False)

These are my models, I have created a serializer for Posts and nested it under a UserPostSerializer.

class PostSerializer(serializers.ModelSerializer):
    class Meta:
        model = Posts
        exclude = ('id', 'created_on', 'updated_on', 'is_deleted')


class UserPostsSerializer(serializers.ModelSerializer):
    posts = PostSerializer(many=True)

    class Meta:
        model = User
        fields = ('user_id', 'posts',)

However, when I create a view like this:

class UserPostsView(generics.ListAPIView):
    queryset = User.objects.all()
    serializer_class = UserPostsSerializer

    def list(self, request, *args, **kwargs):
        queryset = self.get_queryset()
        serializer = self.get_serializer(queryset, many=True)
        response = Response(serializer.data)
        return response

my API returns { "detail": "Not found." }

Ideally, the view should list all the users along with their posts. Something like:

{
   "user_id": "abcd",
   "posts": {  
       "url": "http:....com",
       "description": "Lorem ipsum"
       }  
}

Answer 1

The issue was with the ordering of the URLs, I had called it this way:

    urlpatterns = [
                   path('list', UserListView.as_view(), name='user list'),
                   path('<str:id>', UserDetailView.as_view(), name='user detail'),
                   path('posts', UserPostsView.as_view(), name='user posts')]

this way it was mapping my request to UserDetailView, since < str:id > is a catch-all and was called before 'posts', Django was trying to find an user with an user_id 'posts'. The URL for my UserPostsView should have preceded the URL for my UserDetailView, like:

   urlpatterns = [
                  path('list', UserListView.as_view(), name='user list'),
                  path('posts', UserPostsView.as_view(), name='user posts'),
                  path('<str:id>', UserDetailView.as_view(), name='user detail')]

This fixes the error and I am able to see the data in the required format.