mirror of
https://github.com/encode/django-rest-framework.git
synced 2024-12-04 23:44:07 +03:00
225 lines
9.6 KiB
Markdown
225 lines
9.6 KiB
Markdown
<a class="github" href="viewsets.py"></a>
|
|
|
|
# ViewSets
|
|
|
|
> After routing has determined which controller to use for a request, your controller is responsible for making sense of the request and producing the appropriate output.
|
|
>
|
|
> — [Ruby on Rails Documentation][cite]
|
|
|
|
|
|
Django REST framework allows you to combine the logic for a set of related views in a single class, called a `ViewSet`. In other frameworks you may also find conceptually similar implementations named something like 'Resources' or 'Controllers'.
|
|
|
|
A `ViewSet` class is simply **a type of class-based View, that does not provide any method handlers** such as `.get()` or `.post()`, and instead provides actions such as `.list()` and `.create()`.
|
|
|
|
The method handlers for a `ViewSet` are only bound to the corresponding actions at the point of finalizing the view, using the `.as_view()` method.
|
|
|
|
Typically, rather than explicitly registering the views in a viewset in the urlconf, you'll register the viewset with a router class, that automatically determines the urlconf for you.
|
|
|
|
## Example
|
|
|
|
Let's define a simple viewset that can be used to list or retrieve all the users in the system.
|
|
|
|
class UserViewSet(viewsets.ViewSet):
|
|
"""
|
|
A simple ViewSet that for listing or retrieving users.
|
|
"""
|
|
def list(self, request):
|
|
queryset = User.objects.all()
|
|
serializer = UserSerializer(queryset, many=True)
|
|
return Response(serializer.data)
|
|
|
|
def retrieve(self, request, pk=None):
|
|
queryset = User.objects.all()
|
|
user = get_object_or_404(queryset, pk=pk)
|
|
serializer = UserSerializer(user)
|
|
return Response(serializer.data)
|
|
|
|
If we need to, we can bind this viewset into two separate views, like so:
|
|
|
|
user_list = UserViewSet.as_view({'get': 'list'})
|
|
user_detail = UserViewSet.as_view({'get': 'retrieve'})
|
|
|
|
Typically we wouldn't do this, but would instead register the viewset with a router, and allow the urlconf to be automatically generated.
|
|
|
|
router = DefaultRouter()
|
|
router.register(r'users', UserViewSet)
|
|
urlpatterns = router.urls
|
|
|
|
Rather than writing your own viewsets, you'll often want to use the existing base classes that provide a default set of behavior. For example:
|
|
|
|
class UserViewSet(viewsets.ModelViewSet):
|
|
"""
|
|
A viewset for viewing and editing user instances.
|
|
"""
|
|
serializer_class = UserSerializer
|
|
queryset = User.objects.all()
|
|
|
|
There are two main advantages of using a `ViewSet` class over using a `View` class.
|
|
|
|
* Repeated logic can be combined into a single class. In the above example, we only need to specify the `queryset` once, and it'll be used across multiple views.
|
|
* By using routers, we no longer need to deal with wiring up the URL conf ourselves.
|
|
|
|
Both of these come with a trade-off. Using regular views and URL confs is more explicit and gives you more control. ViewSets are helpful if you want to get up and running quickly, or when you have a large API and you want to enforce a consistent URL configuration throughout.
|
|
|
|
## Marking extra methods for routing
|
|
|
|
The default routers included with REST framework will provide routes for a standard set of create/retrieve/update/destroy style operations, as shown below:
|
|
|
|
class UserViewSet(viewsets.ViewSet):
|
|
"""
|
|
Example empty viewset demonstrating the standard
|
|
actions that will be handled by a router class.
|
|
|
|
If you're using format suffixes, make sure to also include
|
|
the `format=None` keyword argument for each action.
|
|
"""
|
|
|
|
def list(self, request):
|
|
pass
|
|
|
|
def create(self, request):
|
|
pass
|
|
|
|
def retrieve(self, request, pk=None):
|
|
pass
|
|
|
|
def update(self, request, pk=None):
|
|
pass
|
|
|
|
def partial_update(self, request, pk=None):
|
|
pass
|
|
|
|
def destroy(self, request, pk=None):
|
|
pass
|
|
|
|
If you have ad-hoc methods that you need to be routed to, you can mark them as requiring routing using the `@link` or `@action` decorators. The `@link` decorator will route `GET` requests, and the `@action` decorator will route `POST` requests.
|
|
|
|
For example:
|
|
|
|
from django.contrib.auth.models import User
|
|
from rest_framework import viewsets
|
|
from rest_framework import status
|
|
from rest_framework.decorators import action
|
|
from rest_framework.response import Response
|
|
from myapp.serializers import UserSerializer, PasswordSerializer
|
|
|
|
class UserViewSet(viewsets.ModelViewSet):
|
|
"""
|
|
A viewset that provides the standard actions
|
|
"""
|
|
queryset = User.objects.all()
|
|
serializer_class = UserSerializer
|
|
|
|
@action()
|
|
def set_password(self, request, pk=None):
|
|
user = self.get_object()
|
|
serializer = PasswordSerializer(data=request.DATA)
|
|
if serializer.is_valid():
|
|
user.set_password(serializer.data['password'])
|
|
user.save()
|
|
return Response({'status': 'password set'})
|
|
else:
|
|
return Response(serializer.errors,
|
|
status=status.HTTP_400_BAD_REQUEST)
|
|
|
|
The `@action` and `@link` decorators can additionally take extra arguments that will be set for the routed view only. For example...
|
|
|
|
@action(permission_classes=[IsAdminOrIsSelf])
|
|
def set_password(self, request, pk=None):
|
|
...
|
|
|
|
The `@action` decorator will route `POST` requests by default, but may also accept other HTTP methods, by using the `method` argument. For example:
|
|
|
|
@action(methods=['POST', 'DELETE'])
|
|
def unset_password(self, request, pk=None):
|
|
...
|
|
---
|
|
|
|
# API Reference
|
|
|
|
## ViewSet
|
|
|
|
The `ViewSet` class inherits from `APIView`. You can use any of the standard attributes such as `permission_classes`, `authentication_classes` in order to control the API policy on the viewset.
|
|
|
|
The `ViewSet` class does not provide any implementations of actions. In order to use a `ViewSet` class you'll override the class and define the action implementations explicitly.
|
|
|
|
## GenericViewSet
|
|
|
|
The `GenericViewSet` class inherits from `GenericAPIView`, and provides the default set of `get_object`, `get_queryset` methods and other generic view base behavior, but does not include any actions by default.
|
|
|
|
In order to use a `GenericViewSet` class you'll override the class and either mixin the required mixin classes, or define the action implementations explicitly.
|
|
|
|
## ModelViewSet
|
|
|
|
The `ModelViewSet` class inherits from `GenericAPIView` and includes implementations for various actions, by mixing in the behavior of the various mixin classes.
|
|
|
|
The actions provided by the `ModelViewSet` class are `.list()`, `.retrieve()`, `.create()`, `.update()`, and `.destroy()`.
|
|
|
|
#### Example
|
|
|
|
Because `ModelViewSet` extends `GenericAPIView`, you'll normally need to provide at least the `queryset` and `serializer_class` attributes. For example:
|
|
|
|
class AccountViewSet(viewsets.ModelViewSet):
|
|
"""
|
|
A simple ViewSet for viewing and editing accounts.
|
|
"""
|
|
queryset = Account.objects.all()
|
|
serializer_class = AccountSerializer
|
|
permission_classes = [IsAccountAdminOrReadOnly]
|
|
|
|
Note that you can use any of the standard attributes or method overrides provided by `GenericAPIView`. For example, to use a `ViewSet` that dynamically determines the queryset it should operate on, you might do something like this:
|
|
|
|
class AccountViewSet(viewsets.ModelViewSet):
|
|
"""
|
|
A simple ViewSet for viewing and editing the accounts
|
|
associated with the user.
|
|
"""
|
|
serializer_class = AccountSerializer
|
|
permission_classes = [IsAccountAdminOrReadOnly]
|
|
|
|
def get_queryset(self):
|
|
return self.request.user.accounts.all()
|
|
|
|
Also note that although this class provides the complete set of create/list/retrieve/update/destroy actions by default, you can restrict the available operations by using the standard permission classes.
|
|
|
|
## ReadOnlyModelViewSet
|
|
|
|
The `ReadOnlyModelViewSet` class also inherits from `GenericAPIView`. As with `ModelViewSet` it also includes implementations for various actions, but unlike `ModelViewSet` only provides the 'read-only' actions, `.list()` and `.retrieve()`.
|
|
|
|
#### Example
|
|
|
|
As with `ModelViewSet`, you'll normally need to provide at least the `queryset` and `serializer_class` attributes. For example:
|
|
|
|
class AccountViewSet(viewsets.ReadOnlyModelViewSet):
|
|
"""
|
|
A simple ViewSet for viewing accounts.
|
|
"""
|
|
queryset = Account.objects.all()
|
|
serializer_class = AccountSerializer
|
|
|
|
Again, as with `ModelViewSet`, you can use any of the standard attributes and method overrides available to `GenericAPIView`.
|
|
|
|
# Custom ViewSet base classes
|
|
|
|
You may need to provide custom `ViewSet` classes that do not have the full set of `ModelViewSet` actions, or that customize the behavior in some other way.
|
|
|
|
## Example
|
|
|
|
To create a base viewset class that provides `create`, `list` and `retrieve` operations, inherit from `GenericViewSet`, and mixin the required actions:
|
|
|
|
class CreateListRetrieveViewSet(mixins.CreateModelMixin,
|
|
mixins.ListModelMixin,
|
|
mixins.RetrieveModelMixin,
|
|
viewsets.GenericViewSet):
|
|
"""
|
|
A viewset that provides `retrieve`, `update`, and `list` actions.
|
|
|
|
To use it, override the class and set the `.queryset` and
|
|
`.serializer_class` attributes.
|
|
"""
|
|
pass
|
|
|
|
By creating your own base `ViewSet` classes, you can provide common behavior that can be reused in multiple viewsets across your API.
|
|
|
|
[cite]: http://guides.rubyonrails.org/routing.html
|