使用Django REST Framework序列化外键数组

Question

I have a model with custom "ArrayField" (for a Postgres array field), which stores an array of foreign keys to another model. Django doesn't enforce the relation, but what I put in there are foreign keys.

class Foo(model):
    bars  =  ArrayField(models.IntegerField())

class Bar(model):
    blah  = models.CharField()

So the value of the 'bars' field is like [3,64,7,34,...] where the numbers are non-enforced foreign keys to Bar. When rendering Foos, I'd like to render the related objects represented in this field using Django REST Framework:

{ "foo" : {  "bars" : [ {"blah":"asdf"},
                        {"blah":"asdf"}
                      ]
          }
}

I'm having trouble figuring out how that should be expressed in the serializer:

class BarSerializer(serializers.ModelSerializer):
    class Meta:
        fields = ('blah')

    blah     = serializersCharField()


class FooSerializer(serializers.ModelSerializer):
    class Meta:
        fields = ('bars')

    # bars     = BarSerializer(many=True)
    bars      = SomeSpecialCustomField() #?

How can I get JSON as above when rendering?

Answer 1

Try playing around with this:

class SomeSpecialCustomField(serializers.Field):

    def to_native(self, value):
        queryset = Bar.objects.filter(pk__in=value)
        serializer = BarSerializer(queryset, many=True)
        return serializer.data

Make sure you put proper validations, like checking if the value is a list etc.