Django Rest Framework - #3 Class Based Views

Author: rg3915

content/django-rest-framework-class-based-views.md

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+title: Django Rest Framework - #3 Class Based Views
+Slug: django-rest-framework-class-based-views
+Date: 2018-02-15 23:00
+Tags: Python, Django, REST
+Author: Regis da Silva
+Email:  [email protected]
+Github: rg3915
+Twitter: rg3915
+Category: Python, Django, REST
+
+* 0 - [Quickstart][10]
+* 1 - [Serialization][11]
+* 2 - [Requests & Responses][12]
+* 3 - **Class based views**
+
+Este post é continuação do post [Django Rest Framework Requests & Responses][12].
+
+Finalmente chegamos as views baseadas em classes. A grande vantagem é que com poucas linhas de código já temos nossa API pronta.
+
+Veja como fica a [views.py](https://github.com/rg3915/drf/blob/b0aa989ffc756e6dc5f65e172dfb43d47127d743/core/views.py):
+
+```python
+from django.http import Http404
+from rest_framework.views import APIView
+from rest_framework.response import Response
+from rest_framework import status
+from core.models import Person
+from core.serializers import PersonSerializer
+
+
+class PersonList(APIView):
+    """
+    List all persons, or create a new person.
+    """
+
+    def get(self, request, format=None):
+        persons = Person.objects.all()
+        serializer = PersonSerializer(persons, many=True)
+        return Response(serializer.data)
+
+    def post(self, request, format=None):
+        serializer = PersonSerializer(data=request.data)
+        if serializer.is_valid():
+            serializer.save()
+            return Response(serializer.data, status=status.HTTP_201_CREATED)
+        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
+
+
+class PersonDetail(APIView):
+    """
+    Retrieve, update or delete a person instance.
+    """
+
+    def get_object(self, pk):
+        try:
+            return Person.objects.get(pk=pk)
+        except Person.DoesNotExist:
+            raise Http404
+
+    def get(self, request, pk, format=None):
+        person = self.get_object(pk)
+        serializer = PersonSerializer(person)
+        return Response(serializer.data)
+
+    def put(self, request, pk, format=None):
+        person = self.get_object(pk)
+        serializer = PersonSerializer(person, data=request.data)
+        if serializer.is_valid():
+            serializer.save()
+            return Response(serializer.data)
+        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
+
+    def delete(self, request, pk, format=None):
+        person = self.get_object(pk)
+        person.delete()
+        return Response(status=status.HTTP_204_NO_CONTENT)
+```
+
+E `urls.py`:
+
+```python
+urlpatterns = [
+    path('persons/', views.PersonList.as_view()),
+    path('persons/<int:pk>/', views.PersonDetail.as_view()),
+]
+```
+
+## Usando Mixins
+
+Repare que no exemplo anterior tivemos que definir os métodos `get()`, `post()`, `put()` e `delete()`. Podemos reduzir ainda mais esse código com o uso de mixins.
+
+```python
+from rest_framework import mixins
+from rest_framework import generics
+from core.models import Person
+from core.serializers import PersonSerializer
+
+
+class PersonList(mixins.ListModelMixin,
+                 mixins.CreateModelMixin,
+                 generics.GenericAPIView):
+    queryset = Person.objects.all()
+    serializer_class = PersonSerializer
+
+    def get(self, request, *args, **kwargs):
+        return self.list(request, *args, **kwargs)
+
+    def post(self, request, *args, **kwargs):
+        return self.create(request, *args, **kwargs)
+
+
+class PersonDetail(mixins.RetrieveModelMixin,
+                   mixins.UpdateModelMixin,
+                   mixins.DestroyModelMixin,
+                   generics.GenericAPIView):
+    queryset = Person.objects.all()
+    serializer_class = PersonSerializer
+
+    def get(self, request, *args, **kwargs):
+        return self.retrieve(request, *args, **kwargs)
+
+    def put(self, request, *args, **kwargs):
+        return self.update(request, *args, **kwargs)
+
+    def delete(self, request, *args, **kwargs):
+        return self.destroy(request, *args, **kwargs)
+```
+
+## Usando generic class-based views
+
+E para finalizar usamos `ListCreateAPIView` e `RetrieveUpdateDestroyAPIView` que já tem todos os métodos embutidos.
+
+```python
+from rest_framework import generics
+from core.models import Person
+from core.serializers import PersonSerializer
+
+
+class PersonList(generics.ListCreateAPIView):
+    queryset = Person.objects.all()
+    serializer_class = PersonSerializer
+
+
+class PersonDetail(generics.RetrieveUpdateDestroyAPIView):
+    queryset = Person.objects.all()
+    serializer_class = PersonSerializer
+```
+
+Versão final de [views.py](https://github.com/rg3915/drf/blob/263ca63e5c8e2dd2e0f5d6c88c5733fcfdab4f74/core/views.py).
+
+Abraços.
+
+[10]: http://pythonclub.com.br/django-rest-framework-quickstart.html
+[11]: http://pythonclub.com.br/django-rest-framework-serialization.html
+[12]: http://pythonclub.com.br/django-rest-framework-requests-responses.html