目錄
mixin類和Generic類
導入
from rest_framework.mixins import CreateModelMixin, RetrieveModelMixin, ListModelMixin, UpdateModelMixin, DestroyModelMixin
from rest_framework.generics import GenericAPIView
CreateModelMixin 創建
源碼路徑為 rest_framework —> mixing.py —>CreateModelMixin
class CreateModelMixin(object):
"""
Create a model instance.
"""
def create(self, request, *args, **kwargs):
# 傳入前端傳入的數據，進行反序列化
serializer = self.get_serializer(data=request.data)
# 判斷是否全部都校驗通過 通過了就執行下面語句
# raise_exception=True 不通過直接報錯，下面也不會執行
serializer.is_valid(raise_exception=True)
# 執行perform_create 實際就是.save() 保存
self.perform_create(serializer)
# 頭部信息忽略
headers = self.get_success_headers(serializer.data)
# 遵循規范返回創建對象的數據
# status 狀態信息，對應的是一個個狀態碼
return Response(serializer.data, status=status.HTTP_201_CREATED, headers=headers)
def perform_create(self, serializer):
serializer.save()
def get_success_headers(self, data):
try:
return {'Location': str(data[api_settings.URL_FIELD_NAME])}
except (TypeError, KeyError):
return {}
視圖使用-post
class PublishView(CreateModelMixin,GenericAPIView):
queryset = models.Publish.objects.all()
# 內部執行的時候CreateModelMixin調用了serializer_class
serializer_class = PublishSerializers
# 執行post請求就說明要添加數據
def post(self, request, *args, **kwargs):
# 執行create 自己沒有就執行CreateModelMixin
# 也就是上面的CreateModelMixin源碼解析
return self.create(request, *args, **kwargs)
ListModelMixin - 查看多條數據
源碼路徑為 rest_framework —> mixing.py —>ListModelMixin
class ListModelMixin(object):
"""
List a queryset.
"""
def list(self, request, *args, **kwargs):
# 過濾相關
# 這個時候調用了GenericAPIView內的get_queryset
queryset = self.filter_queryset(self.get_queryset())
# 分頁相關
page = self.paginate_queryset(queryset)
# page不為空的情況下
if page is not None:
# 序列化多條
serializer = self.get_serializer(page, many=True)
# 返回序列化的數據
return self.get_paginated_response(serializer.data)
serializer = self.get_serializer(queryset, many=True)
return Response(serializer.data)
視圖-get-取所有數據
class PublishView(ListModelMixin,GenericAPIView):
queryset = models.Publish.objects.all()
serializer_class = PublishSerializers
def get(self, request, *args, **kwargs):
return self.list(request, *args, **kwargs)
RetrieveModelMixin 獲取單條數據
源碼路徑為 rest_framework —> mixing.py—>RetrieveModelMixin
class RetrieveModelMixin(object):
def retrieve(self, request, *args, **kwargs):
# 獲取單條
instance = self.get_object()
# 獲取到序列化返回
serializer = self.get_serializer(instance)
return Response(serializer.data)
視圖-get-取指定數據
class PublishDetailView(RetrieveModelMixin, UpdateModelMixin, DestroyModelMixin, GenericAPIView):
queryset = models.Publish.objects.all()
serializer_class = PublishSerializers
# 獲取指定一條
def get(self, request, *args, **kwargs):
return self.retrieve(request, *args, **kwargs)
UpdateModelMixin 更新單條數據
源碼路徑為 rest_framework —> mixing.py—>UpdateModelMixin
class UpdateModelMixin(object):
"""
Update a model instance.
"""
def update(self, request, *args, **kwargs):
partial = kwargs.pop('partial', False)
# 要序列化單條數據
instance = self.get_object()
# 序列化
serializer = self.get_serializer(instance, data=request.data, partial=partial)
# 校驗是否全部通過
serializer.is_valid(raise_exception=True)
# 直接保存
self.perform_update(serializer)
if getattr(instance, '_prefetched_objects_cache', None):
instance._prefetched_objects_cache = {}
return Response(serializer.data)
def perform_update(self, serializer):
serializer.save()
def partial_update(self, request, *args, **kwargs):
kwargs['partial'] = True
return self.update(request, *args, **kwargs)
視圖 - put- 更新指定數據
class PublishDetailView(RetrieveModelMixin, UpdateModelMixin, DestroyModelMixin, GenericAPIView):
queryset = models.Publish.objects.all()
serializer_class = PublishSerializers
# 更新指定數據
def put(self, request, *args, **kwargs):
return self.update(request, *args, **kwargs)
DestroyModelMixin - 刪除指定數據
class DestroyModelMixin(object):
def destroy(self, request, *args, **kwargs):
# 獲取要刪除的數據
instance = self.get_object()
# 直接執行刪除
self.perform_destroy(instance)
# 返回信息
return Response(status=status.HTTP_204_NO_CONTENT)
def perform_destroy(self, instance):
instance.delete()
視圖 - delete- 刪除指定數據
class PublishDetailView(RetrieveModelMixin, UpdateModelMixin, DestroyModelMixin, GenericAPIView):
queryset = models.Publish.objects.all()
serializer_class = PublishSerializers
# 刪除指定數據
def delete(self, request, *args, **kwargs):
return self.destroy(request, *args, **kwargs)
GenericAPIView 通用的apiview
get_queryset(self):
def get_queryset(self):
assert self.queryset is not None, (
"'%s' should either include a `queryset` attribute, "
"or override the `get_queryset()` method."
% self.__class__.__name__
)
# 這個時候的queryset 是傳遞進來的queryset對象
queryset = self.queryset
# 判斷是否是QuerySet，不是QuerySet 自動.all()
# 說明queryset可以直接給它傳遞一個對象如 models.Publish.objects
if isinstance(queryset, QuerySet):
# Ensure queryset is re-evaluated on each request.
queryset = queryset.all()
# 返回queryset對象
return queryset
generics 里面組合了mixins里面方法和GenericAPIView
導入
from rest_framework.generics import ListCreateAPIView,RetrieveUpdateDestroyAPIView
url
url(r'^publish/$', views.publishView.as_view()),
url(r'^publish/(?P<pk>\d+)/$', views.PublishDetailView.as_view())
ListCreateAPIView源碼 創建與查詢多條
class ListCreateAPIView(mixins.ListModelMixin,
mixins.CreateModelMixin,
GenericAPIView):
# 獲取多條
def get(self, request, *args, **kwargs):
return self.list(request, *args, **kwargs)
# 創建數據
def post(self, request, *args, **kwargs):
return self.create(request, *args, **kwargs)
RetrieveUpdateDestroyAPIView源碼 查詢單條 更新 刪除
class RetrieveUpdateDestroyAPIView(mixins.RetrieveModelMixin,
mixins.UpdateModelMixin,
mixins.DestroyModelMixin,
GenericAPIView):
# 獲取指定數據
def get(self, request, *args, **kwargs):
return self.retrieve(request, *args, **kwargs)
# 更新全部
def put(self, request, *args, **kwargs):
return self.update(request, *args, **kwargs)
# 局部更新
def patch(self, request, *args, **kwargs):
return self.partial_update(request, *args, **kwargs)
# 刪除
def delete(self, request, *args, **kwargs):
return self.destroy(request, *args, **kwargs)
視圖
from rest_framework.generics import ListCreateAPIView,RetrieveUpdateDestroyAPIView
class publishView(ListCreateAPIView):
queryset=models.Publish.objects.all()
serializer_class=PublishSerializers
class PublishDetailView(RetrieveUpdateDestroyAPIView):
queryset=models.Publish.objects.all()
serializer_class=PublishSerializers
ModelViewSet 多種請求映射
導入：
from rest_framework.viewsets import ModelViewSet
- 路由：
url(r'^publish/$', views.PublishView.as_view({'get':'list','post':'create'})),
url(r'^publish/(?P<pk>\d+)/$', views.PublishView.as_view({'get':'retrieve','put':'update','delete':'destroy'})),
- 視圖：
from rest_framework.viewsets import ModelViewSet
class PublishView(ModelViewSet):
queryset=models.Publish.objects.all()
serializer_class=PublishSerializers
# 這里面雖然可以滿足方法的請求但是有時候我們會更具業務的需要，去修改，我們可以重寫指定的方法，如create等
為什么可以可以做到請求映射？
- 主要是重寫了as_view方法
1.ModelViewSet中唯一不通的就是繼承了GenericViewSet,上面的方法中繼承的是GenericAPIView 倆者不同
class ModelViewSet(mixins.CreateModelMixin,
mixins.RetrieveModelMixin,
mixins.UpdateModelMixin,
mixins.DestroyModelMixin,
mixins.ListModelMixin,
GenericViewSet):
pass
2.GenericViewSet中pass??,繼承了之前的GenericAPIView，但是多繼承了一個ViewSetMixin
class GenericViewSet(ViewSetMixin, generics.GenericAPIView):
pass
3.ViewSetMixin中仔細看as_view 和原生的Django.views.View.as_view的區別,多了一個參數
Django.views.View.as_view
def as_view(cls, **initkwargs):
pass
ViewSetMixin.as_view
def as_view(cls, actions=None, **initkwargs):
pass
4.所以路由中配置的字典{'get': 'list', 'post': 'create'}給了actions
url(r'^publish/$', views.PublishView.as_view({'get': 'list', 'post': 'create'})),
url(r'^publish/(?P<pk>\d+)/$',
views.PublishView.as_view({'get': 'retrieve', 'put': 'update', 'delete': 'destroy'})),
5.ViewSetMixin.as_view 源碼中如果可以看出如果繼承了ViewSetMixin沒有傳遞actions直接就會異常
if not actions:
raise TypeError("The `actions` argument must be provided when "
"calling `.as_view()` on a ViewSet. For example "
"`.as_view({'get': 'list'})`")
6.ViewSetMixin.as_view核心代碼,也就是這一段代碼讓我們的請求直接執行對應的執行函數
def view(request, *args, **kwargs):
self = cls(**initkwargs)
# 調用了傳入的actions 賦值給了action_map
self.action_map = actions
# {'get': 'list', 'post': 'create'}
# 解壓賦值 請求給了method 處理參數給了action
for method, action in actions.items():
# self是自定義的那個路由函數的對象
# 通過反射去對象中找action
# handler就相當於 那個執行方法的內存地址
handler = getattr(self, action)
# 反射設置值 把執行方法的內存地址覆蓋了請求，每次來請求執行的就是對於的執行函數
setattr(self, method, handler)
if hasattr(self, 'get') and not hasattr(self, 'head'):
self.head = self.get
self.request = request
self.args = args
self.kwargs = kwargs
# And continue as usual
return self.dispatch(request, *args, **kwargs)
自定義ViewSetMixin類
- 相當於映射 指定請求來了執行指定方法
from rest_framework.viewsets import ViewSetMixin
from rest_framework.views import APIView
# 要注意繼承的順序如果APIView繼承在前按照mro列表先執行它里面的as_views,所以要放在前面
class Test(ViewSetMixin, APIView):
def test(self, request, pk):
print('自定義請求收到參數:', pk)
return Response()
url
url(r'^test/(?P<pk>\d+)/$', views.Test.as_view({'get': 'test'})),