Class-based views help in composing reusable bits of behavior. Django REST Framework provides several pre-built views that allow us to reuse common functionality and keep our code DRY. In this section, we will dig deep into the different class-based views in Django REST Framework.

APIView

APIView class provides commonly required behavior for standard list and detail views. With APIView class, we can rewrite the root view as a class-based view. They provide action methods such as get(), post(), put(), patch(), and delete() rather than defining the handler methods.

Creating views using APIView

Let’s take a look at how to create views using APIView. The views.py file module as follows:

from django.shortcuts import render 
from django.http import Http404 

from rest_framework.views import APIView 
from rest_framework.response import Response 
from rest_framework import status 

from transformers.models import Transformer 
from transformers.serializers import TransformerSerializer 

class TransformerList(APIView): 
	""" 
	List all Transformers, or create a new Transformer 
	"""

	def get(self, request, format=None): 
		transformers = Transformer.objects.all() 
		serializer = TransformerSerializer(transformers, many=True) 
		return Response(serializer.data) 

	def post(self, request, format=None): 
		serializer = TransformerSerializer(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 TransformerDetail(APIView): 
	""" 
	Retrieve, update or delete a transformer instance 
	"""
	def get_object(self, pk): 
		# Returns an object instance that should 
		# be used for detail views. 
		try: 
			return Transformer.objects.get(pk=pk) 
		except Transformer.DoesNotExist: 
			raise Http404 

	def get(self, request, pk, format=None): 
		transformer = self.get_object(pk) 
		serializer = TransformerSerializer(transformer) 
		return Response(serializer.data) 

	def put(self, request, pk, format=None): 
		transformer = self.get_object(pk) 
		serializer = TransformerSerializer(transformer, data=request.data) 
		if serializer.is_valid(): 
			serializer.save() 
			return Response(serializer.data) 
		return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST) 

	def patch(self, request, pk, format=None): 
		transformer = self.get_object(pk) 
		serializer = TransformerSerializer(transformer, 
										data=request.data, 
										partial=True) 
		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): 
		transformer = self.get_object(pk) 
		transformer.delete() 
		return Response(status=status.HTTP_204_NO_CONTENT) 

#python #django-rest