django-rest-framework返回创建的对象，但字段较少

Question

在POST方法中创建对象时，如何仅返回创建对象的几个字段？这取自文档：

def post(self, request, format=None):
        serializer = SnippetSerializer(data=request.data)
        if serializer.is_valid():
            serializer.save()
            return Response(serializer.data, status=status.HTTP_201_CREATED)
        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)

这里serializer.data包括序列化程序中定义的所有字段，但我只想返回其中的几个。

Answer 1

好吧，我在这里看到了多种可能性：首先（我最喜欢的）是将请求对象发送到序列化器，然后序列化器将动态选择您想要的字段：

def post(self, request, format=None):
        serializer = SnippetSerializer(data=request.data,context={'request': request})
        if serializer.is_valid():
            serializer.save()
            return Response(serializer.data, status=status.HTTP_201_CREATED)
        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)

然后在序列化器内部：

class SnippetSerializer(serializers.IDontKnow):
    class Meta:
        model = YourModel
        fields = ('url', 'field1','field2','field3')
        write_only_fields = ()
    def __init__(self, *args, **kwargs):
        super(SnippetSerializer, self).__init__(*args, **kwargs)
        if self.context != {}:
            request = self.context['request']
            if request.method == 'POST':
                self.write_only_fields = {'field1':self.fields['field1'], 'field3':self.fields['field3']}

这应该使field1和field3仅可写，因此不会返回它们。

其次，也许更简单的解决方案是定义其他序列化程序，这对于post方法是唯一的：

def post(self, request, format=None):
    serializer = PostSnippetSerializer(data=request.data)
    if serializer.is_valid():
        serializer.save()
        return Response(serializer.data, status=status.HTTP_201_CREATED)
    return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)

您可以指定不希望重新调整的字段：

 class PostSnippetSerializer(serializers.IDontKnow):
        class Meta:
            model = YourModel
            fields = ('url', 'field1','field2','field3')
            write_only_fields = ('field1','field3')

不会返回field1和field 3作为响应，

第三种方法是直接在您的视图中创建响应：

def post(self, request, format=None):
        serializer = SnippetSerializer(data=request.data)
        if serializer.is_valid():
            serializer.save()
            results = {'url': serializer.data['url'],'field2':serializer.data['field2']}
            return Response(results, status=status.HTTP_201_CREATED)
        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)

这将仅返回url和field2，因此将保存field1和field3，但不返回。