使用Django Rest框架序列化列表中对象的自定义字段

Question

I have a model that looks something like this:

class Foo:
    name = CharField()

class Bar:
    foo = ForeignKey(Foo, related_name='bars')
    bar_text = TextField()

I want the serialized version of Foo to look something like:

{
    bars : [
        "baz",
        "whizz"
    ]
}

ie rather than displaying the id s of each bar, displaying the 'bar_text' field inside instead.

I think I'm aware of how to do this normally, ie if we had a single bar attribute under each 'Foo' rather than a list:

class FooSerializer(models.ModelSerializer):
    bar = serializers.TextField(source='bar.bar_text')

But I'm not sure how to perform the same override when using a 'bars' list, and don't seem to be able to find anything obvious!

EDIT: I forgot to mention - I think I can do this by overriding the restore_object function, but if there's a neater way, I'm all ears.

Answer 1

A solution that nearly works for me is to override the bars attribute on the FooSerializer with a BarSerializer :

class FooSerializer(models.ModelSerializer):
    bars = BarSerializer(many=True)

However, this gives me the following when serialized:

{
    bars: [
        {
            'bar_text' : 'baz',
        },
        { 
            'bar_text' : 'whizz'
        }
    ]
}

Which is fine, but I really want a list of bar_text s rather than key/value pairs. What's more, if I add more fields to Bar that I do not want to be serialized into Foo , I have no control over which are displayed here vs. a pure serialization of Bar . If I don't get a better solution I'll accept this shortly.

Answer 2

It sounds like you are looking for a SlugRelatedField instead of a nested serializer.

class FooSerializer(models.ModelSerializer):
    bars = serializers.SlugRelatedField(slug_field='bar_text')