support for @Sibling many-to-many relationships?

[jaredh159]

Hi there. Thanks for this amazing library and all the work you put into it! It's been fantastic to use so far! 🙏

I'm having trouble modeling a many-to-many pivot-table based sibling relationship with vapor+graphql-kit. I'm a bit at a loss of even how to approach the problem. I'm wondering if it's something that is not supported yet, or if possibly I just don't know how to set up the schema and resolvers to make it work.

I see that you extended Graphiti's Field class here to add keypath-based resolution specifically for children and parent relationships. I'm wondering if something similar would need to be done for sibling relationships. Or is it not possible without some deeper work in the library? Or is it possible by dropping down and working at the Graphiti layer itself somehow?

Have you written an example with some code somewhere of how to do this? (I ask because I relied heavily on your excellent blog posts with the Todo examples when getting up and running).

Any info or pointers would be greatly appreciated. Thanks again!

[alexsteinerde]

Hi, awesome that you like the package!

The current version doesn't support Siblings relationships yet. But as you already pointed out this can be achieved by adding another extension to Graphiti's Field class.
I quickly prototyped a solution that works with the same syntax as Child and Parent relationships do (including a new example in the ToDo demo application).

// Siblings Relationship
extension Graphiti.Field where Arguments == NoArguments, Context == Request, ObjectType: Model {
    public convenience init<ToType: Model, ThroughType: Model>(
        _ name: FieldKey,
        with keyPath: KeyPath<ObjectType, SiblingsProperty<ObjectType, ToType, ThroughType>>
    ) where FieldType == [TypeReference<ToType>] {
        self.init(name.description, at: { (type) -> (Request, NoArguments, EventLoopGroup) throws -> EventLoopFuture<[ToType]> in
            return { (context: Request, arguments: NoArguments, eventLoop: EventLoopGroup) in
                return type[keyPath: keyPath].query(on: context.db).all()
            }
        }, as: [TypeReference<ToType>].self)
    }
}

I'll clean up my code, add some documentation and ship a new version in the next day or two. When I have the time, I'll also publish a blog post explaining its usage. But it should be straightforward to use.

I hope this will help you solve your use case.
I really appreciate that you use GraphQL+Server Side Swift. I think it's a great combination.

[jaredh159]

@alexsteinerde thanks for getting back so quickly. I copied your sample code into my project, and it seems to work perfectly, at least at first glance. I'll just use that until you're able to get a new release out, no hurry. Really appreciate it!

[alexsteinerde]

I published a new release 2.2.0 with the mentioned extension included.
If you encounter any bugs, feel free to reopen the issue.

[jaredh159]

New version works great! Thanks again!