Django Rest Framework Serializer 向 Meta.fields 添加元素

Question

我创建了一个自定义序列化程序类，将答案复制到this question，但在此示例中，fields 参数替换了原始Meta.fields 属性，我想要的是添加 Meta.fields 的新元素。有什么办法可以做到吗？

这是我的序列化器：

class DynamicModelSerializer(serializers.ModelSerializer):
    def __init__(self, *args, **kwargs):
        fields = kwargs.pop('fields', None)
        add_fields = kwargs.pop('add_fields', None)
        exclude = kwargs.pop('exclude', None)
        nest = kwargs.pop('nest', None)

        if nest is not None:
            self.Meta.depth = nest

        super(DynamicModelSerializer, self).__init__(*args, **kwargs)

        if fields is not None:
            allowed = set(fields)
            existing = set(self.fields.keys())
            for field_name in existing - allowed:
                self.fields.pop(field_name)

        if exclude is not None:
            for field_name in exclude:
                self.fields.pop(field_name)

Answer 1

是的，您可以这样做，如下更改您的 DynamicModelSerializer：

class DynamicModelSerializer(serializers.ModelSerializer):
    def __init__(self, *args, **kwargs):
        fields = kwargs.pop('fields', None)
        add_fields = kwargs.pop('add_fields', None)
        exclude = kwargs.pop('exclude', None)
        nest = kwargs.pop('nest', None)

        if nest is not None:
            self.Meta.depth = nest

        super(DynamicModelSerializer, self).__init__(*args, **kwargs)

        if fields is not None:
            allowed = set(fields)
            existing = set(self.fields.keys())
            for field_name in existing - allowed:
                self.fields.pop(field_name)

        if add_fields is not None:
            for field_name, field_class in add_fields.items():
                ### first pop the old field class from the fields if it's there
                if field_name in self.fields:
                    self.fields.pop(field_name)
                ### now add the field to the fields
                self.fields[field_name] = field_class


        if exclude is not None:
            for field_name in exclude:
                self.fields.pop(field_name)

用法：

class ExampleSerializer(DynamicModelSerializer):
    test1 = serializers.CharField()

    class Meta:
        model = Example
        fields = ('test1', 'test2', 'test3')


ser = ExampleSerializer(fields=('test1', 'test3'), add_fields={'addField1': serializers.CharField()})