21

我正在尝试确定使用 django 和 django-rest-framework 将根元素添加到所有 json 响应的最佳方法。

我认为添加自定义渲染器是完成我想要实现的目标的最佳方式，这就是我迄今为止想出的：

from rest_framework.renderers import JSONRenderer

class CustomJSONRenderer(JSONRenderer):
#override the render method
def render(self, data, accepted_media_type=None, renderer_context=None):
    #call super, as we really just want to mess with the data returned
    json_str = super(CustomJSONRenderer, self).render(data, accepted_media_type, renderer_context)
    root_element = 'contact'

    #wrap the json string in the desired root element
    ret = '{%s: %s}' % (root_element, json_str) 

    return ret

现在棘手的部分是root_element根据render()被调用的视图动态设置。

任何指针/建议将不胜感激，

干杯

4

2 回答 2

14

对于后代，以下是最终解决方案。它与原来的相比略有增长，因为它现在也重新格式化了分页结果。

我之前也应该指定 JSON 根元素的原因是为了与 Ember 前端解决方案集成。

序列化器：

from rest_framework.serializers import ModelSerializer
from api.models import Contact

class ContactSerializer(ModelSerializer):
    class Meta:
        model = Contact
        #define the resource we wish to use for the root element of the response
        resource_name = 'contact' 
        fields = ('id', 'first_name', 'last_name', 'phone_number', 'company')

渲染器：

from rest_framework.renderers import JSONRenderer

class CustomJSONRenderer(JSONRenderer):
    """
        Override the render method of the django rest framework JSONRenderer to allow the following:
        * adding a resource_name root element to all GET requests formatted with JSON
        * reformatting paginated results to the following structure {meta: {}, resource_name: [{},{}]}

        NB: This solution requires a custom pagination serializer and an attribute of 'resource_name'
        defined in the serializer
    """
    def render(self, data, accepted_media_type=None, renderer_context=None):
        response_data = {}

        #determine the resource name for this request - default to objects if not defined
        resource = getattr(renderer_context.get('view').get_serializer().Meta, 'resource_name', 'objects')

        #check if the results have been paginated
        if data.get('paginated_results'):
            #add the resource key and copy the results
            response_data['meta'] = data.get('meta')
            response_data[resource] = data.get('paginated_results')
        else:
            response_data[resource] = data

        #call super to render the response
        response = super(CustomJSONRenderer, self).render(response_data, accepted_media_type, renderer_context)

        return response

分页：

from rest_framework import pagination, serializers

class CustomMetaSerializer(serializers.Serializer):
    next_page = pagination.NextPageField(source='*')
    prev_page = pagination.PreviousPageField(source='*')
    record_count = serializers.Field(source='paginator.count')

class CustomPaginationSerializer(pagination.BasePaginationSerializer):
    # Takes the page object as the source
    meta = CustomMetaSerializer(source='*')
    results_field = 'paginated_results'
于 2013-02-14T22:30:00.297 回答
5

感谢 ever.wakeful 让我完成了 95% 的工作。

就个人而言，我想将元数据添加到某个对象的每个 api 请求中，无论它是否被分页。我还想简单地传入我手动定义的 dict 对象。

调整自定义渲染器

class CustomJSONRenderer(renderers.JSONRenderer):
    def render(self, data, accepted_media_type=None, renderer_context=None):
        response_data = {}
        # Name the object list 
        object_list = 'results'
        try:
            meta_dict = getattr(renderer_context.get('view').get_serializer().Meta, 'meta_dict')
        except:
            meta_dict = dict()
        try:
            data.get('paginated_results')
            response_data['meta'] = data['meta']
            response_data[object_list] = data['results']
        except:
            response_data[object_list] = data
            response_data['meta'] = dict()
            # Add custom meta data
            response_data['meta'].update(meta_dict)
            # Call super to render the response
            response = super(CustomJSONRenderer, self).render(response_data, accepted_media_type, renderer_context)
        return response

父序列化器和查看示例

class MovieListSerializer(serializers.ModelSerializer):
    class Meta:
        model = Movie
        meta_dict = dict()
        meta_dict['foo'] = 'bar'

class MovieViewSet(generics.ListAPIView):
    queryset = Movie.objects.exclude(image__exact = "")
    serializer_class = MovieListSerializer
    permission_classes = (IsAdminOrReadOnly,)
    renderer_classes = (CustomJSONRenderer,)
    pagination_serializer_class = CustomPaginationSerializer
    paginate_by = 10
于 2013-05-30T06:12:34.130 回答