Django Rest Framework combine multiple querysets in one api endpoint

Question

How can I connect the output of lists of a particular model, whose instances are filtered by different fields? For example, I have an Places model and two different url. In one, the entire list is displayed, and in the other only the instances with new_place = True. Do an API using django-filter.

models.py

class Places(models.Model):
    main_photo = models.ImageField(upload_to = 'album/')
    place = models.CharField(max_length=100)
    new_place = models.BooleanField(default = True)
    editor_choice = models.BooleanField(default = False, verbose_name = "Editors choice")
    most_popular = models.BooleanField(default = False, verbose_name = "Most popular")

serializer.py

class PlaceSerializer(ModelSerializer):
        
    url = HyperlinkedIdentityField(
    view_name='places_api:detail',
    lookup_field='pk'
    )
    class Meta:
        model = Places
        fields = (
            'url',
            'id',
            'main_photo',
            'name',
            'new_place',
            'most_popular', 
            'editor_choice',                        
        )

full_list_views.py

class PlacesListAPIView(ListAPIView):
    queryset = Places.objects.all()
    serializer_class = PlaceSerializer

new_places_views.py

class PlacesNewListAPIView(ListAPIView):
    queryset = Places.objects.all()
    serializer_class = PlaceSerializer
    filter_backends = (DjangoFilterBackend,)
    filter_fields = ('new_place',)

urls.py

url(r'^new/$', views.PlacesNewListAPIView.as_view(), name = 'list_new'),
url(r'^$', views.PlacesListAPIView.as_view(), name = 'place_list'),

This all works well on different urls. But what should I do to get both lists on one page. List of NEW at the top and full list at the bottom of the page?

Answer 1

You could do something like this. Using QuerySet.union() to merge several querysets.

This example does not support pagination. I suspect that you would have to write a custom pagination class if you need pagination.

class MultiFilterPlacesListView(ListAPIView):
     """Custom queryset api view. Does not implement pagination"""

     pagination_class = None
     queryset = Places.objects.all()
     slice_size = 10  # count limit for each of the source queries

     def get_queryset(self):
         """Combine queries from new, editor choice and popular"""
         new_qs = self.queryset.filter(new_place=True)[:self.slice_size]
         editor_qs = self.queryset.filter(editor_choice=True)[:self.slice_size]
         popular_qs = self.queryset.filter(popular=True)[:self.slice_size]

         return new_qs.union(editor_qs, popular_qs, all=True)