> Before a TemplateResponse instance can be returned to the client, it must be rendered. The rendering process takes the intermediate representation of template and context, and turns it into the final byte stream that can be served to the client.
REST framework's `Request` class extends the standard `HttpRequest`, adding support for parsing multiple content types, allowing browser-based `PUT`, `DELETE` and other methods, and adding flexible per-request authentication.
REST framework's `Request` class extends the standard `HttpRequest`, adding support for parsing multiple content types, allowing browser-based `PUT`, `DELETE` and other methods, and adding flexible per-request authentication.
REST framework provides a simple `APIView` class, built on Django's `django.generics.views.View`. The `APIView` class ensures five main things:
REST framework provides an `APIView` class, which subclasses Django's `View` class.
1. Any requests inside the view will become `Request` instances.
`APIView` classes are different from regular `View` classes in the following ways:
2.`Request` instances will have their `renderers` and `authentication` attributes automatically set.
3.`Response` instances will have their `parsers` and `serializer` attributes automatically set.
4.`APIException` exceptions will be caught and return appropriate responses.
5. Any permissions provided will be checked prior to passing the request to a handler method.
Additionally there are a some minor extras, such as providing a default `options` handler, setting some common headers on the response prior to return, and providing the useful `initial()` and `final()` hooks.
* Requests passed to the handler methods will be REST framework's `Request` instances, not Django's `HttpRequest` instances.
* Handler methods may return REST framework's `Response`, instead of Django's `HttpResponse`. The view will manage content negotiation and setting the correct renderer on the response.
* Any `APIException` exceptions will be caught and mediated into appropriate responses.
* Incoming requests will be authenticated and appropriate permission and/or throttle checks will be run before dispatching the request to the handler method.
## APIView
Using the `APIView` class is pretty much the same as using a regular `View` class, as usual, the incoming request is dispatched to an appropriate handler method such as `.get()` or `.post()`. Additionally, a number of attributes may be set on the class that control various aspects of the API policy.
## Method handlers
For example:
Describe that APIView handles regular .get(), .post(), .put(), .delete() etc...
users = [user.username for user in User.objects.all()]
return Response(users)
## .final(request, response, *args, **kwargs)
## API policy attributes
## .parsers
The following attributes control the pluggable aspects of API views.
## .renderers
### .renderer_classes
## .serializer
### .parser_classes
## .authentication
### .authentication_classes
## .permissions
### .throttle_classes
## .headers
### .permission_classes
### .content_negotiation_class
## API policy instantiation methods
The following methods are used by REST framework to instantiate the various pluggable API policies. You won't typically need to override these methods.
### .get_renderers(self)
### .get_parsers(self)
### .get_authenticators(self)
### .get_throttles(self)
### .get_permissions(self)
### .get_content_negotiator(self)
## API policy implementation methods
The following methods are called before dispatching to the handler method.
### .check_permissions(...)
### .check_throttles(...)
### .perform_content_negotiation(...)
## Dispatch methods
The following methods are called directly by the view's `.dispatch()` method.
These perform any actions that need to occur before or after calling the handler methods such as `.get()`, `.post()`, `put()` and `.delete()`.
### .initial(self, request, *args, **kwargs)
Performs any actions that need to occur before the handler method gets called.
This method is used to enforce permissions and throttling, and perform content negotiation.
You won't typically need to override this method.
### .handle_exception(self, exc)
Any exception thrown by the handler method will be passed to this method, which either returns a `Response` instance, or re-raises the exception.
The default implementation handles any subclass of `rest_framework.exceptions.APIException`, as well as Django's `Http404` and `PermissionDenied` exceptions, and returns an appropriate error response.
If you need to customize the error responses your API returns you should subclass this method.
Ensures that any `Response` object returned from the handler method will be rendered into the correct content type, as determined by the content negotation.
