Class-Based Views, thesarfo

To get started with class based views, you need to import the APIView class from the rest_framework.views module. And then create a class that inherits from the APIView. Then you can define methods that show what you want to do. see below

class ProductList(APIView):
    def get(self, request):
        queryset = Product.objects.select_related('collection').all()
        serializer = ProductSerializer(queryset, many=True,     context={'request': request})
        return Response(serializer.data)

    def post(self, request):
        serializer = ProductSerializer(data=request.data)
        serializer.is_valid(raise_exception=True)
        serializer.save()
        return Response(serializer.data, status=status.HTTP_201_CREATED)

This is the same logic as the ‘product_list’ view function where we get to specify http methods on top of such functions and use if else blocks.

Now that we have a class based view, in order to use it..you have to go to your urls.py file and then reference the class view. see below

urlpatterns = [
    path('products/', views.ProductList.as_view())
    '''adding the as_view() method converts the classbased view into a function that works as a normal function view'''
]

This is how the product_detail function will be converted into a class based view, with the same functionality

class ProductDetail(APIView):
    def get(self, request, id):
        product = get_object_or_404(Product, pk=id)
        serializer = ProductSerializer(product)
        return Response(serializer.data)

    def put(self, request, id):
        product = get_object_or_404(Product, pk=id)
        serializer = ProductSerializer(product, data=request.data)
        serializer.is_valid(raise_exception=True)
        serializer.save()
        return Response(serializer.data)

    def delete(self, request, id):
        product = get_object_or_404(Product, pk=id)
        if product.orderitems_set.count() > 0:
            return Response({'error': 'Product cannot be deleted because it is associated with an order item'}, status=HTTP_405)
        product.delete()
        return Response(status=status.HTTP_204_NO_CONTENT)

Note that you need to update its urlpattern as well.