added CBV class-based views.

my_app/urls.py

 from django.urls import path
-from .views import DemoUsersListCreateView, DemoUsersRetrieveUpdateDestroyView
+# from .views import DemoUsersListCreateView, DemoUsersRetrieveUpdateDestroyView
+from my_app import views
 
 urlpatterns = [
-    path('demo_user/', DemoUsersListCreateView.as_view(), name='list_demo_user'),
-    path('demo_user/<int:pk>/', DemoUsersRetrieveUpdateDestroyView.as_view(), name='edit_demo_user'),
+    # CBV
+    path('cbv/demo_user/', views.DemoUserList.as_view(), name='CBV List User'),
+    path('cbv/demo_user/<int:pk>/', views.DemoUserDetail.as_view(), name='CBV Detail User'),
+    # GCBV
+    path('gcbv/demo_user/', views.DemoUsersListCreateView.as_view(), name='list_demo_user'),
+    path('gcbv/demo_user/<int:pk>/', views.DemoUsersRetrieveUpdateDestroyView.as_view(), name='edit_demo_user'),
 ]
 

my_app/views.py

 # from django.shortcuts import render
 
-# Create your views here.
-
-from rest_framework import generics
+# Import custom model and serializer
 from .models import DemoUsers
 from .serializers import DemoUsersSerializer
+
+# Import for GCBV
+from rest_framework import generics
 from rest_framework.permissions import IsAuthenticated
+from django.http import Http404
+
+# Import for CBV
+from rest_framework.views import APIView
+from rest_framework.response import Response
+from rest_framework import status
+
+"""
+CBV - Class based views
+"""
+# Used to query multiple items or create new item
+class DemoUserList(APIView):
+
+    # Query all items
+    def get(self, request, format=None):
+        demo_users = DemoUsers.objects.all()
+        serializer = DemoUsersSerializer(demo_users, many=True)
+        return Response(serializer.data)
+
+    # Create new item
+    def post(self, request, format=None):
+        serializer = DemoUsersSerializer(data=request.data)
+        if serializer.is_valid():
+            serializer.save(created_by=self.request.user.username)
+            return Response(serializer.data, status=status.HTTP_201_CREATED)
+        else:
+            return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
+
+    # Override get_serializer to show correct payload in API document
+    def get_serializer(self):
+        return DemoUsersSerializer()
+
+# Used to query/update/delete single item
+class DemoUserDetail(APIView):
+
+    # Implementation of get single item
+    def get_object(self, pk):
+        try:
+            return DemoUsers.objects.get(pk=pk)
+        except DemoUsers.DoesNotExist:
+            raise Http404
+
+    # Get single item
+    def get(self, request, pk, format=None):
+        demoUser = self.get_object(pk)
+        serializer = DemoUsersSerializer(demoUser)
+        return Response(serializer.data)
+
+    # Update single item
+    def put(self, request, pk, format=None):
+        demoUser = self.get_object(pk)
+        serializer = DemoUsersSerializer(demoUser, data=request.data)
+        if serializer.is_valid():
+            serializer.save(last_updated_by=self.request.user.username)
+            return Response(serializer.data)
+        else:
+            return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
+
+    # Update partial single item
+    def patch(self, request, pk, format=None):
+        demoUser = self.get_object(pk)
+        serializer = DemoUsersSerializer(demoUser, data=request.data, partial=True)
+        if serializer.is_valid():
+            serializer.save(last_updated_by=self.request.user.username)
+            return Response(serializer.data)
+        else:
+            return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
+
+    # Delete single item
+    def delete(self, request, pk, format=None):
+        demoUser = self.get_object(pk)
+        demoUser.delete()
+        return Response(status=status.HTTP_204_NO_CONTENT)
+
+    # Override get_serializer to show correct payload in API document
+    def get_serializer(self):
+        return DemoUsersSerializer()
+
 
 class DemoUsersListCreateView(generics.ListCreateAPIView):
     queryset = DemoUsers.objects.all()
@@ -13,7 +92,6 @@ class DemoUsersListCreateView(generics.ListCreateAPIView):
     permission_classes = (IsAuthenticated,)
 
     def perform_create(self, serializer):
-        print('user type in creation:', type(self.request.user))
         serializer.save(created_by=self.request.user.username)
 
 class DemoUsersRetrieveUpdateDestroyView(generics.RetrieveUpdateDestroyAPIView):
@@ -22,5 +100,4 @@ class DemoUsersRetrieveUpdateDestroyView(generics.RetrieveUpdateDestroyAPIView):
     permission_classes = (IsAuthenticated,)
 
     def perform_update(self, serializer):
-        print('user type in update:', type(self.request.user))
         serializer.save(last_updated_by=self.request.user.username)