Add fields on a relay connection?

[blb-ventures]

Add fields on a relay connection?

[bellini666]

@dennisv you need to define your connection as a generic class, just like the original, and pass the NodeType captured by the Generic in Connection, just like this:

@gql.type
class CustomConnection(Generic[NodeType], Connection[NodeType]):
    ...

[dennisv]

Thanks for the quick fix and feedback @bellini666 !

I got it to work by doing this:

from strawberry_django_plus.relay import NodeType

@gql.type
class CustomConnection(gql.Connection[NodeType]):
    ...

[bellini666]

@K0Te I just made this change (0762f40) which got released in 1.23.

It allows to define a custom Connection class for a Node, similar to how graphene does. It also allows the Connection to define a custom Edge.

Do you think this is enough?

[bellini666]

Hi @eloff ,

Currently you would need to implement your own Edge and Connection classes and override their logic. But I'm thinking in how to make that relay implementation more generic to allow things like what you want to do.

I'll probably take a look at this soon

[eloff]

Ok, good to know. I'll come up with a temporary workaround for now, but I'll revisit it when you close this ticket.

[K0Te]

More generic connections would simplify migration from graphene-django.
I am currently migrating project that uses multiple subtotals in connections.
For example:

class AccountClientConnection(Connection):
    total_account_clients = graphene.Int()
    total_active_account_clients = graphene.Int()
    active_clients_count = graphene.Int()

Such use-case is trivial with graphene-django connection_class, but complicated with the current connection implementation in strawberry.

[dennisv]

@bellini666 I'm trying to add some fields to a connection as well and can't seem to get it to work using CONNECTION_CLASS

Could it be that it is still always using the default Connection because of this line?

strawberry-django-plus/strawberry_django_plus/relay.py

Line 951 in 2931b1b

Connection[get_args(resolved)[0]], # type:ignore

I'm trying it like this:

@gql.django.type(models.ObjectType)
class ObjectType(gql.Node):
    name: gql.auto

@gql.type
class TestObjectTypeConnection(gql.Connection):
    test: str = "test"

ObjectType.CONNECTION_CLASS = TestObjectTypeConnection

@gql.type
class ObjectTypeQuery:
    @gql.connection
    def object_types(
        self,
        ...
    ) -> Iterable[ObjectType]:
        ...

But the test field does not show up in graphiql and returns "Cannot query field 'test' on type 'ObjectTypeConnection'."

[bellini666]

Hey @dennisv ,

I just noticed that the field was not using the CONNECTION_CLASS to create itself.
I just published the version 1.25.1, which should solve this issue. Can you please try to use it and confirm to me if it works?

[dennisv]

@bellini666 I get a bit further now, but it's now throwing the following:
TypeError: <class '[...].TestObjectTypeConnection'> is not a generic class