Eager-load multiple relationships through `@with`

[chescos]

Is your feature proposal related to a problem? Please describe.

It seems that it is currently not possible to eager-load multiple relationships through the @with directive.

Describe the solution you'd like

I think it should either be possible to use the @with directive more than once on a single field, or the @with directive should accept an array of relationships.

• Using the @with directive multiple times: I'm not sure if it's currently possible to use any directive more than once on a single field. Is this being prevented for some reason?
• Accepting an array of relations through the @with directive: The question is how to handle scopes then, should they be part of the relations array (e.g relations: ["relation" => ["scopeOne", "scopeTwo"]]?

Describe alternatives you've considered

I haven't found any alternative to overcome this issue.

[spawnia]

As of very recently,repeatable directives are now allowed in principle. We will have to add support for that: #1133

I think allowing multiple @with will be the best solution for this use case.

[spawnia]

Repeatable use of the directive is not generally the issue here, it should work in principle - and is now also supported by webonyx/graphql-php

As of now, the way the batch loader instantiation works does enforce that there is always a single batch loader per field. Since the relation to load is passed during the initial construction, subsequent uses of @with don't have a chance to register the relation they want to load.

I am working on moving the relation passing out of the constructor, so the relations to load can added to by multiple directives.

[pfbernardo]

Hi.

I'm using lighthouse 5.0.

I have the following type

type CorrespondenceLetter {
    id: ID!
    name: String!
    target_objects: [CorrespondenceItemTargetObject!]! @with(relation: "targetContacts") @with(relation: "targetContracts") @field(resolver: "App\\GraphQL\\Types\\CorrespondenceItemType@targetObjects")
}

CorrespondenceItemTargetObject is a Union between 2 types.

On the CorrespondenceItemType@targetObjects field resolver I see that only the last relation "targetContracts" is actually loaded.

@spawnia I think it is because of the problem you describe on your last comment.
Do you have any news on this?

[tlaverdure]

Hey, I'm trying to kill some N+1 issues and was wondering is this still in the works?

I'm specifically trying to eager load multiple relationships and also eager load nested relationships using dot syntax a.b.c, but it doesn't look like its supported yet?

type User {
    recommended: Boolean @with(relation: "a")  @with(relation: "a.b") @with(relation: "a.b.c")
}

[spawnia]

I tried reenabling the failing test case for this in #2525 and implemented a fix for it. However, this causes other tests to fail.

The fundamental issue with this is that relations loaded using @with can also have scopes attached, so loading the same relation twice might still be necessary.

[tlaverdure]

Thanks, I'll take a look when I find some time.