Is there a way to get graphene to work with django GenericRelation field?

Question

I have some django model generic relation fields that I want to appear in graphql queries. Does graphene support Generic types?

class Attachment(models.Model):
    user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE)
    content_type = models.ForeignKey(ContentType, on_delete=models.CASCADE)
    object_id = models.PositiveIntegerField()
    content_object = GenericForeignKey('content_type', 'object_id')
    file = models.FileField(upload_to=user_directory_path)

class Aparto(models.Model):
    agency = models.CharField(max_length=100, default='Default')
    features = models.TextField()
    attachments = GenericRelation(Attachment)

graphene classes:

class ApartoType(DjangoObjectType):
    class Meta:
        model = Aparto

class Query(graphene.ObjectType):
    all  = graphene.List(ApartoType)
    def resolve_all(self, info, **kwargs):
        return Aparto.objects.all()

schema = graphene.Schema(query=Query)

I expect the attachments field to appear in the graphql queries results. Only agency and features are showing.

Answer 1

You need to expose Attachment to your schema. Graphene needs a type to work with for any related fields, so they need to be exposed as well.

In addition, you're likely going to want to resolve related attachments, so you'll want to add a resolver for them.

In your graphene classes, try:

class AttachmentType(DjangoObjectType):
    class Meta:
        model = Attachment

class ApartoType(DjangoObjectType):
    class Meta:
        model = Aparto

    attachments = graphene.List(AttachmentType)
    def resolve_attachments(root, info):
        return root.attachments.all()