How can I resolve custom fields for django models using django_graphene?
Looking at graphene_django, I see they have a bunch of resolvers picking up django model fields mapping them to graphene types.
I have a subclass of JSONField I'd also like to be picked up.
:
# models
class Recipe(models.Model):
name = models.CharField(max_length=100)
instructions = models.TextField()
ingredients = models.ManyToManyField(
Ingredient, related_name='recipes'
)
custom_field = JSONFieldSubclass(....)
# schema
class RecipeType(DjangoObjectType):
class Meta:
model = Recipe
custom_field = ???
I know I could write a separate field and resolver pair for a Query, but I'd prefer it to be available as part of the schema for that model.
What I realize I could do:
class RecipeQuery:
custom_field = graphene.JSONString(id=graphene.ID(required=True))
def resolve_custom_field(self, info, **kwargs):
id = kwargs.get('id')
instance = get_item_by_id(id)
return instance.custom_field.to_json()
But -- this means a separate round trip, to get the id then get the custom_field for that item, right?
Is there a way I could have it seen as part of the RecipeType schema?
Ok, I can get it working by using:
# schema
class RecipeType(DjangoObjectType):
class Meta:
model = Recipe
custom_field = graphene.JSONString(resolver=lambda my_obj, resolve_obj: my_obj.custom_field.to_json())
(the custom_field
has a to_json
method)
I figured it out without deeply figuring out what is happening in this map between graphene types and the django model field types.
It's based on this: https://docs.graphene-python.org/en/latest/types/objecttypes/#resolvers
Same function name, but parameterized differently.