Directly using Django's JSONResponse in the Tutorial (#4935)

* directly using Django's JSONResponse

* fixed JsonResponse typo

* added safe=False to JsonResponse

* removed unnecessary 'safe=False' in JsonResponse

docs/tutorial/1-serialization.md

@@ -216,26 +216,15 @@ It's important to remember that `ModelSerializer` classes don't do anything part
 Let's see how we can write some API views using our new Serializer class.
 For the moment we won't use any of REST framework's other features, we'll just write the views as regular Django views.
 
-We'll start off by creating a subclass of HttpResponse that we can use to render any data we return into `json`.
-
 Edit the `snippets/views.py` file, and add the following.
 
-    from django.http import HttpResponse
+    from django.http import HttpResponse, JsonResponse
     from django.views.decorators.csrf import csrf_exempt
     from rest_framework.renderers import JSONRenderer
     from rest_framework.parsers import JSONParser
     from snippets.models import Snippet
     from snippets.serializers import SnippetSerializer
 
-    class JSONResponse(HttpResponse):
-        """
-        An HttpResponse that renders its content into JSON.
-        """
-        def __init__(self, data, **kwargs):
-            content = JSONRenderer().render(data)
-            kwargs['content_type'] = 'application/json'
-            super(JSONResponse, self).__init__(content, **kwargs)
-
 The root of our API is going to be a view that supports listing all the existing snippets, or creating a new snippet.
 
     @csrf_exempt
@@ -246,15 +235,15 @@ The root of our API is going to be a view that supports listing all the existing
         if request.method == 'GET':
             snippets = Snippet.objects.all()
             serializer = SnippetSerializer(snippets, many=True)
-            return JSONResponse(serializer.data)
+            return JsonResponse(serializer.data, safe=False)
 
         elif request.method == 'POST':
             data = JSONParser().parse(request)
             serializer = SnippetSerializer(data=data)
             if serializer.is_valid():
                 serializer.save()
-                return JSONResponse(serializer.data, status=201)
-            return JSONResponse(serializer.errors, status=400)
+                return JsonResponse(serializer.data, status=201)
+            return JsonResponse(serializer.errors, status=400)
 
 Note that because we want to be able to POST to this view from clients that won't have a CSRF token we need to mark the view as `csrf_exempt`.  This isn't something that you'd normally want to do, and REST framework views actually use more sensible behavior than this, but it'll do for our purposes right now.
 
@@ -272,15 +261,15 @@ We'll also need a view which corresponds to an individual snippet, and can be us
 
         if request.method == 'GET':
             serializer = SnippetSerializer(snippet)
-            return JSONResponse(serializer.data)
+            return JsonResponse(serializer.data)
 
         elif request.method == 'PUT':
             data = JSONParser().parse(request)
             serializer = SnippetSerializer(snippet, data=data)
             if serializer.is_valid():
                 serializer.save()
-                return JSONResponse(serializer.data)
-            return JSONResponse(serializer.errors, status=400)
+                return JsonResponse(serializer.data)
+            return JsonResponse(serializer.errors, status=400)
 
         elif request.method == 'DELETE':
             snippet.delete()