restful 在接口中獲取 request.user

 結論：在serializer中可以調用request

有下面的接口

class TestSer(serializers.ModelSerializer):
    xx = serializers.SerializerMethodField()　　　　　　　　 自定義的字段

    class Meta:
        model = models.Topic
        fields = '__all__'

    def get_xx(self,obj):　　　　　　　　　　　　　　　　　　　　寫什么就顯示什么
        return 124
 
class Test(ListAPIView):
    queryset = models.Topic.objects
    serializer_class = TestSer

問題是 在 get_xx 中如何獲取 request

    def get_xx(self,obj):
        # 獲取 request
        self.context['request']
        return 124

解析

用戶進來走的是

class Test(ListAPIView):
    queryset = models.Topic.objects
    serializer_class = TestSer

要執行一個   GET 的 方法 本身沒有去找父類  ListAPIView

class ListAPIView(mixins.ListModelMixin,
                  GenericAPIView):
    """
    Concrete view for listing a queryset.
    """
    def get(self, request, *args, **kwargs):
        return self.list(request, *args, **kwargs)

父類ListAPIView的get方法 返回一個list 自己的也沒有， 父類ListAPIView也沒有 在繼續找上門的父類  ListModelMixin

class ListModelMixin(object):
    """
    List a queryset.
    """
    def list(self, request, *args, **kwargs):
        queryset = self.filter_queryset(self.get_queryset())

        page = self.paginate_queryset(queryset)
        if page is not None:
            serializer = self.get_serializer(page, many=True)
            return self.get_paginated_response(serializer.data)
　　　　
        serializer = self.get_serializer(queryset, many=True)
        return Response(serializer.data)

分析上面的代碼看到

# 執行get_queryset也是先去自己的類找沒有 父類ListAPIView沒有在找ListModelMixin也沒有

queryset = self.filter_queryset(self.get_queryset())

現在去   GenericAPIView  這個類有點長 

我們可以看到有  get_queryset 的方法  進去  我把注釋寫到里面  標好了步驟

class GenericAPIView(views.APIView):
    """
    Base class for all other generic views.
    """
    # You'll need to either set these attributes,
    # or override `get_queryset()`/`get_serializer_class()`.
    # If you are overriding a view method, it is important that you call
    # `get_queryset()` instead of accessing the `queryset` property directly,
    # as `queryset` will get evaluated only once, and those results are cached
    # for all subsequent requests.
    queryset = None
    serializer_class = None

    # If you want to use object lookups other than pk, set 'lookup_field'.
    # For more complex lookup requirements override `get_object()`.
    lookup_field = 'pk'
    lookup_url_kwarg = None

    # The filter backend classes to use for queryset filtering
    filter_backends = api_settings.DEFAULT_FILTER_BACKENDS

    # The style to use for queryset pagination.
    pagination_class = api_settings.DEFAULT_PAGINATION_CLASS

    def get_queryset(self):
        """
        Get the list of items for this view.
        This must be an iterable, and may be a queryset.
        Defaults to using `self.queryset`.

        This method should always be used rather than accessing `self.queryset`
        directly, as `self.queryset` gets evaluated only once, and those results
        are cached for all subsequent requests.

        You may want to override this if you need to provide different
        querysets depending on the incoming request.

        (Eg. return a list of items that is specific to the user)
        """
        assert self.queryset is not None, (
            "'%s' should either include a `queryset` attribute, "
            "or override the `get_queryset()` method."
            % self.__class__.__name__
        )
　　　　　# 第一步
　　　　　# 這個調用的self.qyeryset 也是先去自己的里面找 這次我們有，他有一個判斷 我們自己寫的語句不加all的時候他給我們加
　　　　　# 我們寫的是 queryset = models.Topic.objects
　　　　　# 在回到 ListMoselMixin 分頁我們先不看 serializer = self.get_serializer(queryset, many=True

        queryset = self.queryset
        if isinstance(queryset, QuerySet):
            # Ensure queryset is re-evaluated on each request.
            queryset = queryset.all()
        return queryset

    def get_object(self):
        """
        Returns the object the view is displaying.

        You may want to override this if you need to provide non-standard
        queryset lookups.  Eg if objects are referenced using multiple
        keyword arguments in the url conf.
        """
        queryset = self.filter_queryset(self.get_queryset())

        # Perform the lookup filtering.
        lookup_url_kwarg = self.lookup_url_kwarg or self.lookup_field

        assert lookup_url_kwarg in self.kwargs, (
            'Expected view %s to be called with a URL keyword argument '
            'named "%s". Fix your URL conf, or set the `.lookup_field` '
            'attribute on the view correctly.' %
            (self.__class__.__name__, lookup_url_kwarg)
        )

        filter_kwargs = {self.lookup_field: self.kwargs[lookup_url_kwarg]}
        obj = get_object_or_404(queryset, **filter_kwargs)

        # May raise a permission denied
        self.check_object_permissions(self.request, obj)

        return obj
　　# 第二步

     def get_serializer(self, *args, **kwargs):
        """
        Return the serializer instance that should be used for validating and
        deserializing input, and for serializing output.
        """
　　　　　　# 走的是get_serializer_class 
        serializer_class = self.get_serializer_class()
　　　　　　# 在這里添加了一些東西 在去看下面的這個函數去干了什么 
        kwargs['context'] = self.get_serializer_context()
　　　　　　# 咱們自己寫的實例化的類加括號 實例化 還傳一個kwargs 里面有一個context跳回上一行的注釋 return serializer_class(*args, **kwargs)

    def get_serializer_class(self):
        """
        Return the class to use for the serializer.
        Defaults to using `self.serializer_class`.

        You may want to override this if you need to provide different
        serializations depending on the incoming request.

        (Eg. admins get full serialization, others get basic serialization)
        """
        assert self.serializer_class is not None, (
            "'%s' should either include a `serializer_class` attribute, "
            "or override the `get_serializer_class()` method."
            % self.__class__.__name__
        )
　　　　　　# 就是返回 我們自己寫的 serializer_class = TestSER 在回到上面 return self.serializer_class

    def get_serializer_context(self):
        """
        Extra context provided to the serializer class.
        """
　　　　# 添加了下面的這些東西
　　　　return {
            'request': self.request,
　　　　　　　　# url傳過來的參數
            'format': self.format_kwarg,
            'view': self
        }

.......后面沒有啥用的源碼  我就刪掉啦

好了 其他的都不需要看了

自己寫的  所以 self.context['request'] 就有登陸的人的值
class TestSer(serializers.ModelSerializer):
    xx = serializers.SerializerMethodField()

    class Meta:
        model = models.Topic
        fields = '__all__'

    def get_xx(self,obj):
        # 獲取 request
        self.context['request']
        return 124