Creating class-based views and using generic classes

This time, we will write our API views by declaring class-based views, instead of function-based views. We might code classes that inherit from the rest_framework.views.APIView class and declare methods with the same names than the HTTP verbs we want to process: get, post, put, patch, delete, and so on. These methods receive a request argument as happened with the functions that we created for the views. However, this approach would require us to write a lot of code. Instead, we can take advantage of a set of generic views that we can use as our base classes for our class-based views to reduce the required code to the minimum and take advantage of the behavior that has been generalized in Django REST Framework.

We will create subclasses of the two following generic class views declared in rest_framework.generics:

• ListCreateAPIView: Implements the get method that retrieves a listing of a queryset and the post method that creates a model instance.
• RetrieveUpdateDestroyAPIView: Implements the get, put, patch, and delete methods to retreive, completely update, partially update or delete a model instance.

Those two generic views are composed by combining reusable bits of behavior in Django REST Framework implemented as mixin classes declared in rest_framework.mixins. We can create a class that uses multiple inheritance and combine the features provided by many of these mixin classes. The following line shows the declaration of the ListCreateAPIView class as the composition of ListModelMixin, CreateModelMixin and rest_framework.generics.GenericAPIView:

class ListCreateAPIView(mixins.ListModelMixin, 
                        mixins.CreateModelMixin, 
                        GenericAPIView): 

The following line shows the declaration of the RetrieveUpdateDestroyAPIView class as the composition of RetrieveModelMixin, UpdateModelMixin, DestroyModelMixin and rest_framework.generics.GenericAPIView:

class RetrieveUpdateDestroyAPIView(mixins.RetrieveModelMixin, 
                                   mixins.UpdateModelMixin, 
                                   mixins.DestroyModelMixin, 
                                   GenericAPIView): 

Now, we will create a Django class based views that will use the previously explained generic classes and the serializer classes to return JSON representations for each HTTP request that our API will handle. We will just have to specify a queryset that retrieves all the objects in the queryset attribute and the serializer class in the serializer_class attribute for each subclass that we declare. The generic classes will do the rest for us. In addition, we will declare a name attribute with the string name we will use to identify the view.