Implement recipe filter feature

README.md

@@ -39,6 +39,11 @@ REST API with Python, Django REST Framework and Docker using Test Driven Develop
         * Delete ingredient
     - Recipe Image API
         * Upload image to recipe
+- Filter recipes by tags and ingredients
+    - How to use:
+        - `<host>/api/recipes/?tags=<comma_separated_tag_ids>`
+        - `<host>/api/recipes/?ingredients=<comma_separated_ingredient_ids>`
+
 
 ## Documentation
 The API documentation is created using [drf-spectacular](https://drf-spectacular.readthedocs.io/en/latest/).

app/recipe/views.py

@@ -1,7 +1,12 @@
 """
 Views for the recipe APIs.
 """
-from drf_spectacular.utils import extend_schema, extend_schema_view
+from drf_spectacular.utils import (
+    extend_schema_view,
+    extend_schema,
+    OpenApiParameter,
+    OpenApiTypes,
+)
 
 from rest_framework import viewsets, mixins, status
 from rest_framework.decorators import action
@@ -18,6 +23,18 @@
     list=extend_schema(
         summary='Retrieve a list of recipes',
         description='Retrieve a list of recipes for the authenticated user.',
+        parameters=[
+            OpenApiParameter(
+                'tags',
+                OpenApiTypes.STR,
+                description='Comma separated list of tags IDs to filter',
+            ),
+            OpenApiParameter(
+                'ingredients',
+                OpenApiTypes.STR,
+                description='Comma separated list of ingredients IDs to filter'
+            ),
+        ]
     ),
     create=extend_schema(
         summary='Create a new recipe',
@@ -47,9 +64,29 @@ class RecipeViewSet(viewsets.ModelViewSet):
     authentication_classes = [TokenAuthentication]
     permission_classes = [IsAuthenticated]
 
+    def _params_to_ints(self, qs):
+        """Convert a list of strings to integers."""
+        return [int(str_id) for str_id in qs.split(',')]
+
     def get_queryset(self):
         """Retrieve recipes for authenticated user."""
-        return self.queryset.filter(user=self.request.user).order_by('-id')
+        # retrieve query params provided as string of comma separated values
+        tags = self.request.query_params.get('tags')
+        ingredients = self.request.query_params.get('ingredients')
+        queryset = self.queryset
+
+        # filter queryset based on query params
+        if tags:
+            tag_ids = self._params_to_ints(tags)
+            queryset = queryset.filter(tags__id__in=tag_ids)
+        if ingredients:
+            ingredient_ids = self._params_to_ints(ingredients)
+            queryset = queryset.filter(ingredients__id__in=ingredient_ids)
+
+        # return filtered queryset for authenticated user
+        return queryset.filter(
+            user=self.request.user
+        ).order_by('-id').distinct()
 
     def get_serializer_class(self):
         """Return the serializer class for request."""