Django REST framework(官方教程-六)

教程 6: ViewSets & Routers

REST 框架包含对于​​ViewSets​​的抽象处理，其允许开发者专注于API模块状态与交互，基于约定，使得URL自动处理。 ​​ViewSet​​ 跟 ​​View​​ 相仿, 除了提供的read与update操作以外，它没有get与put操作。 ​​ViewSet​​  只在最后绑定一组方法处理程序, 当实例化一组 views, 特别实在使用​​Router​​ ，其可以处理 复杂的URL导向适合的配置。

用 ViewSets重构

让我们定义当前的视图,并重构viewset

首先 让我们把 ​​UserList​​ 和 ​​UserDetail​​ 视图合并到 ​​UserViewSet中​​. 移除这2个视图, 用一单一class替代它:

from rest_framework import viewsets

class UserViewSet(viewsets.ReadOnlyModelViewSet):
"""
This viewset automatically provides `list` and `detail` actions.
"""
queryset = User.objects.all()
serializer_class = UserSerializer

​​我们已经使用​​​​ReadOnlyModelViewSet​​ class，其自动提供默认的  'read-only' 操作. We're still setting the​​queryset​​ and ​​serializer_class​​ attributes exactly as we did when we were using regular views, but we no longer need to provide the same information to two separate classes. 之后我们移除 ​​SnippetList​​, ​​SnippetDetail​​ 和 ​​SnippetHighlight视图类​​. 我们溢出这3个视图并合并到一个class中。

from rest_framework.decorators import link

class SnippetViewSet(viewsets.ModelViewSet):
"""
This viewset automatically provides `list`, `create`, `retrieve`,
`update` and `destroy` actions.

Additionally we also provide an extra `highlight` action.
"""
queryset = Snippet.objects.all()
serializer_class = SnippetSerializer
permission_classes = (permissions.IsAuthenticatedOrReadOnly,
IsOwnerOrReadOnly,)

@link(renderer_classes=[renderers.StaticHTMLRenderer])
def highlight(self, request, *args, **kwargs):
snippet = self.get_object()
return Response(snippet.highlighted)

def pre_save(self, obj):
obj.owner = self.request.user

此时我们使用 ​​ModelViewSet​​ 以取得 完备的读写操作. Notice 我们也使用 ​​@link​​ 装饰器 以定义一方法 ​​highlight​​. 这个装饰器能被用于任何不适合​​create​​/​​update​​/​​delete方法的​​自定义结点. 使用@lin装饰器以响应GET请求. 如果需要响应POST请求，我们同样可以使用 ​​@action装饰器​​ .

将ViewSets 与 URLs 进行绑定

只有当我们定义URLConf时，处理程序的方法才绑定到操作上。我们首先明确ViewSets创建一组视图。

​​在​​​​urls.py​​ 文件中我们绑定把 ​​ViewSet​​ 绑定到 具体视图中.

from snippets.views import SnippetViewSet, UserViewSet
from rest_framework import renderers

snippet_list = SnippetViewSet.as_view({
'get': 'list',
'post': 'create'
})
snippet_detail = SnippetViewSet.as_view({
'get': 'retrieve',
'put': 'update',
'patch': 'partial_update',
'delete': 'destroy'
})
snippet_highlight = SnippetViewSet.as_view({
'get': 'highlight'
}, renderer_classes=[renderers.StaticHTMLRenderer])
user_list = UserViewSet.as_view({
'get': 'list'
})
user_detail = UserViewSet.as_view({
'get': 'retrieve'
})

urlpatterns = format_suffix_patterns(patterns('snippets.views',
url(r'^$', 'api_root'),
url(r'^snippets/$', snippet_list, name='snippet-list'),
url(r'^snippets/(?P<pk>[0-9]+)/$', snippet_detail, name='snippet-detail'),
url(r'^snippets/(?P<pk>[0-9]+)/highlight/$', snippet_highlight, name='snippet-highlight'),
url(r'^users/$', user_list, name='user-list'),
url(r'^users/(?P<pk>[0-9]+)/$', user_detail, name='user-detail')
))

Using Routers

重写 ​​urls.py​​ 文件.

from django.conf.urls import patterns, url, include
from snippets import views
from rest_framework.routers import DefaultRouter

# Create a router and register our viewsets with it.
router = DefaultRouter()
router.register(r'snippets', views.SnippetViewSet)
router.register(r'users', views.UserViewSet)

# The API URLs are now determined automatically by the router.
# Additionally, we include the login URLs for the browseable API.
urlpatterns = patterns('',
url(r'^', include(router.urls)),
url(r'^api-auth/', include('rest_framework.urls', namespace='rest_framework'))
)

Registering the viewsets with the router is similar to providing a urlpattern. We include two arguments - the URL prefix for the views, and the viewset itself.

The ​​DefaultRouter​​ class we're using also automatically creates the API root view for us, so we can now delete the ​​api_root​​method from our ​​views​​ module.