mirror of
https://github.com/encode/django-rest-framework.git
synced 2024-11-27 12:04:02 +03:00
173 lines
6.7 KiB
Markdown
173 lines
6.7 KiB
Markdown
<a class="github" href="decorators.py"></a> <a class="github" href="views.py"></a>
|
|
|
|
# Class Based Views
|
|
|
|
> Django's class based views are a welcome departure from the old-style views.
|
|
>
|
|
> — [Reinout van Rees][cite]
|
|
|
|
REST framework provides an `APIView` class, which subclasses Django's `View` class.
|
|
|
|
`APIView` classes are different from regular `View` classes in the following ways:
|
|
|
|
* 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.
|
|
|
|
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.
|
|
|
|
For example:
|
|
|
|
from rest_framework.views import APIView
|
|
from rest_framework.response import Response
|
|
from rest_framework import authentication, permissions
|
|
|
|
class ListUsers(APIView):
|
|
"""
|
|
View to list all users in the system.
|
|
|
|
* Requires token authentication.
|
|
* Only admin users are able to access this view.
|
|
"""
|
|
authentication_classes = (authentication.TokenAuthentication,)
|
|
permission_classes = (permissions.IsAdminUser,)
|
|
|
|
def get(self, request, format=None):
|
|
"""
|
|
Return a list of all users.
|
|
"""
|
|
usernames = [user.username for user in User.objects.all()]
|
|
return Response(usernames)
|
|
|
|
## API policy attributes
|
|
|
|
The following attributes control the pluggable aspects of API views.
|
|
|
|
### .renderer_classes
|
|
|
|
### .parser_classes
|
|
|
|
### .authentication_classes
|
|
|
|
### .throttle_classes
|
|
|
|
### .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()`, `patch()` 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.
|
|
|
|
### .initialize_request(self, request, \*args, **kwargs)
|
|
|
|
Ensures that the request object that is passed to the handler method is an instance of `Request`, rather than the usual Django `HttpRequest`.
|
|
|
|
You won't typically need to override this method.
|
|
|
|
### .finalize_response(self, request, response, \*args, **kwargs)
|
|
|
|
Ensures that any `Response` object returned from the handler method will be rendered into the correct content type, as determined by the content negotation.
|
|
|
|
You won't typically need to override this method.
|
|
|
|
---
|
|
|
|
# Function Based Views
|
|
|
|
> Saying [that Class based views] is always the superior solution is a mistake.
|
|
>
|
|
> — [Nick Coghlan][cite2]
|
|
|
|
REST framework also allows you to work with regular function based views. It provides a set of simple decorators that wrap your function based views to ensure they receive an instance of `Request` (rather than the usual Django `HttpRequest`) and allows them to return a `Response` (instead of a Django `HttpResponse`), and allow you to configure how the request is processed.
|
|
|
|
## @api_view()
|
|
|
|
**Signature:** `@api_view(http_method_names)`
|
|
|
|
The core of this functionality is the `api_view` decorator, which takes a list of HTTP methods that your view should respond to. For example, this is how you would write a very simple view that just manually returns some data:
|
|
|
|
from rest_framework.decorators import api_view
|
|
|
|
@api_view(['GET'])
|
|
def hello_world(request):
|
|
return Response({"message": "Hello, world!"})
|
|
|
|
|
|
This view will use the default renderers, parsers, authentication classes etc specified in the [settings](settings).
|
|
|
|
## API policy decorators
|
|
|
|
To override the default settings, REST framework provides a set of additional decorators which can be added to your views. These must come *after* (below) the `@api_view` decorator. For example, to create a view that uses a [throttle](throttling) to ensure it can only be called once per day by a particular user, use the `@throttle_classes` decorator, passing a list of throttle classes:
|
|
|
|
from rest_framework.decorators import api_view, throttle_classes
|
|
from rest_framework.throttling import UserRateThrottle
|
|
|
|
class OncePerDayUserThrottle(UserRateThrottle):
|
|
rate = '1/day'
|
|
|
|
@api_view(['GET'])
|
|
@throttle_classes([OncePerDayUserThrottle])
|
|
def view(request):
|
|
return Response({"message": "Hello for today! See you tomorrow!"})
|
|
|
|
These decorators correspond to the attributes set on `APIView` subclasses, described above.
|
|
|
|
The available decorators are:
|
|
|
|
* `@renderer_classes(...)`
|
|
* `@parser_classes(...)`
|
|
* `@authentication_classes(...)`
|
|
* `@throttle_classes(...)`
|
|
* `@permission_classes(...)`
|
|
|
|
Each of these decorators takes a single argument which must be a list or tuple of classes.
|
|
|
|
[cite]: http://reinout.vanrees.org/weblog/2011/08/24/class-based-views-usage.html
|
|
[cite2]: http://www.boredomandlaziness.org/2012/05/djangos-cbvs-are-not-mistake-but.html
|
|
[settings]: api-guide/settings.md
|
|
[throttling]: api-guide/throttling.md
|