[Django REST framework] 3. Class-based Views

https://www.django-rest-framework.org/tutorial/3-class-based-views/

3 - Class based views - Django REST framework

Class-base views의 장점은

1. 공통의 기능을 재사용할 수 있다.

2. code를 "DRY"하게 유지할 수 있다.

* DRY(Don't Repeat Yourself): 반복[중복]을 줄이는 software pattern

 

class-based views를 사용하여 API를 재작성

이전의 function based views를 class-based views로 바꿔보자

snippets/views.py
from snippets.models import Snippet
from snippets.serializers import SnippetSerializer
from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework import status
from django.http import Http404

class SnippetList(APIView):
    """
    List all code snippets, or create new snippet.
    """
    def get(self, request, format=None):
        snippets = Snippet.objects.all()
        serializer = SnippetSerializer(snippets, many=True)
        return Response(serializer.data)

    def post(self, request, format=None):
        serializer = SnippetSerializer(data=request.data)
        if serializer.is_valid():
            serializer.save()
            return Response(serializer.data, status=status.HTTP_201_CREATED)
        return Response(serializer.data, status=status.HTTP_400_BAD_REQUEST)

class SnippetDetail(APIView):
    """
    Retrieve, update or delete a code snippet.
    """
    def get_object(self, pk):
        try:
            return Snippet.objects.get(pk=pk)
        except Snippet.DoesNotExist:
            raise Http404
    
    def get(self, request, pk, format=None):
        snippet = self.get_object(pk)
        serializer = SnippetSerializer(snippet)
        return Response(serializer.data)

    def put(self, request, pk, format=None):
        snippet = self.get_object(pk)
        serializer = SnippetSerializer(snippet, 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):
        snippet = self.get_object(pk)
        snippet.delete()
        return Response(status=status.HTTP_204_NO_CONTENT)

urls도 바꿔보자

snippets/urls.py
from django.urls import path
from snippets import views
from rest_framework.urlpatterns import format_suffix_patterns

urlpatterns = [
    path('snippets/', views.SnippetList.as_view()),
    path('snippets/<int:pk>/', views.SnippetDetail.as_view()),
]

urlpatterns = format_suffix_patterns(urlpatterns) # format suffix

이전과 같이 잘 동작하는지 확인하고 넘어가자

mixins 사용하기

class-based views는 확장성 면에서 function base보다 유리한데,

이런 장점을 극대화 시켜주는 것이 바로 mixins class이다.

 

mixin classes를 사용해서 views를 재구성해보자

snippets/views.py
from snippets.models import Snippet
from snippets.serializers import SnippetSerializer
from rest_framework import mixins
from rest_framework import generics

class SnippetList(mixins.ListModelMixin, mixins.CreateModelMixin, generics.GenericAPIView):
    queryset = Snippet.objects.all()
    serializer_class = SnippetSerializer

    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 SnippetDetail(mixins.RetrieveModelMixin, mixins.UpdateModelMixin, mixins.DestroyModelMixin, generics.GenericAPIView):
    queryset = Snippet.objects.all()
    serializer_class = SnippetSerializer

    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)

여기서 view는 GenericAPIView를 통해서 빌드했고,

mixins를 더함으로써 .list(), .create() 와 같은 동작을 제공할 수 있게 되는 것이다.

Generic class-based views

사실, REST framework는 이미 mixed-in generic views를 제공함으로써 보다 간편하게 코드를 작성할 수 있게 한다.

from snippets.models import Snippet
from snippets.serializers import SnippetSerializer
from rest_framework import generics

class SnippetList(generics.ListCreateAPIView):
    queryset = Snippet.objects.all()
    serializer_class = SnippetSerializer

class SnippetDetail(generics.RetrieveUpdateDestroyAPIView):
    queryset = Snippet.objects.all()
    serializer_class = SnippetSerializer

views가 엄청 간단해졌다!