将根元素添加到json响应（django-rest-framework）

Question

我想确定使用django和django-rest-framework将根元素添加到所有json响应的最佳方法。

我想添加自定义渲染器是实现我想达到什么是最好的方式，这就是我来了这么远：

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 

棘手的部分现在被动态地设置root_element基于认为render()正在被调用。

任何指针/建议将不胜感激，

干杯

Answer 1

对于后代，下面是最终溶液。它从原来的略有增长，因为它现在也重新分页分页结果。

此外，我应该在之前指出，JSON根元素的原因是与Ember前端解决方案集成。

串行：

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：

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' 

Answer 2

感谢ever.wakeful你为我95％的方式出现。

就我个人而言，我想为某个对象的每个api请求添加元数据，无论它是否分页。我也想简单地传入一个手动定义的字典对象。

调整了自定义呈现

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 

父串行和查看示例

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