Django REST Framework nested serializer having no effect

Question

I am attempting to set up a nested serializer in Django REST Framework, but after following the short guide in the documentation, http://www.django-rest-framework.org/api-guide/relations/#nested-relationships, I have had no change in the serialized data.

models.py

class Franchise(models.Model):
    id = models.AutoField(primary_key=True)
    name = models.CharField(max_length=255)


class Item(models.Model):
    id = models.AutoField(primary_key=True)
    franchise = models.ForeignKey(Franchise, on_delete=None)
    title = models.CharField(max_length=255)

Initial serializers.py

class ItemListSerializer(serializers.ModelSerializer):
    class Meta:
        model = Item
        fields = ('id', 'franchise', 'title')


class FranshiseDetailSerializer(serializers.ModelSerializer):
    class Meta:
        model = Franchise
        fields = ('id', 'name', 'items')

When I query ItemListSerializer with a query set I get back the expected:

[
    {
        "id": 1,
        "franchise": 1,
        "title": "Item 1",
    },
    {
        "id": 2,
        "franchise": 1,
        "title": "Item 2"
    },
    {
        "id": 3,
        "franchise": 2,
        "title": "Item 3",
    }
]

And the expected result when I query FranchiseDetailSerializer with a pre-existing franchise object.

{
    "id": 1,
    "name": "Franchise 1"
}

Now, when I change FranchiseDetailSerializer, as per the DRF guide on nested relations:

class FranshiseDetailSerializer(serializers.ModelSerializer):
    items = ItemListSerializer(many=True, read_only=True)

    class Meta:
        model = Franchise
        fields = ('id', 'name', 'items')

I would expect the get the following result:

{
    "id": 1,
    "name": "Franchise 1"
    "items": [
       {"id": 1, "title": "Item 1", "franchise": 1},
       {"id": 2, "title": "Item 2", "franchise": 1}
    ]
}

But instead, I get no change, as though I hadn't updated FranchiseDetailSerializer at all:

{
    "id": 1,
    "name": "Franchise 1"
}

The worst part about this for me is that I am not getting any kind of error, I'm simply not seeing results.

Any and all help is appreciated, thanks.

Answer 1

Actually you missed a tiny part of docs :)

album = models.ForeignKey(Album, related_name='tracks')

Define related_name in ForeignKey

franchise = models.ForeignKey(Franchise, on_delete=None, related_name='items')

After that stuff started working for me.