[GraphQL] Embedded resources does not work for mutations

[Fgruntjes]

API Platform version(s) affected: 2.5.1

Description
When resources are defined in yaml instead of Doctrine GraphQL will not show them as embedded resources for mutations.

The schema definition

App\Entity\Book:
    collectionOperations: ~
    itemOperations: ~
    attributes:
        normalization_context:
            groups: ['Book']
        denormalization_context:
            groups: ['Book']
    properties:
        id:
            readonly: true
        title:
            required: true
        pages:
            subresource:
                resourceClass: 'App\Entity\Page'
                collection: true

App\Entity\Page:
    collectionOperations: ['get']
    itemOperations: ['get']
    attributes:
        normalization_context:
            groups: ['Book']
        denormalization_context:
            groups: ['Book']
    properties:
        id:
            readonly: true
        content:
            required: true

And serialization config

App\Entity\Book:
    attributes:
        id:
            groups: ['Book']
        title:
            groups: ['Book']
        pages:
            groups: ['Book']

App\Entity\Page:
    attributes:
        id:
            groups: ['Book']
        content:
            groups: ['Book']

Will create the following createBookInput object in graphql

How to reproduce

• Checkout the project https://github.com/Fgruntjes/api-platform-graphql-issue
• composer install
• Open GraphiQl viewer

Additional Context
Similar to these issues but @alanpoulain suggested that they are likely not the same.

• Nested resources in GraphQL without Doctrine api-platform#836
• Subresources in graphQL - iterable instead of correct type (OneToMany relationship) api-platform#1043

[alanpoulain]

It's a known issue. More info here: #1964 and here: #1886.
There is an RFC ongoing for the input union type: https://github.com/graphql/graphql-spec/blob/master/rfcs/InputUnion.md but we can't know when it will be accepted.
The other solution, as I have described here: #1964 (comment) would be to have two fields (IRI + data).

[epashkov]

Is this issue appears only with One-To-Many relation types? I am trying to understand how to get graphql schema with embedded input type for One-To-One relation. And I see that the result just the same.

For example, if we have two entities: User and UserProfile defined as

/**
 * @ApiResource()
 */
class User
{
    /**
     * @var int
     */
    private $id;

    /**
     * @var UserProfile
     */
    private $profile;
}

/**
 * @ApiResource()
 */
class UserProfile
{
    /**
     * @var int
     */
    private $id;

    /**
     * @var User
     */
    private $user;
}

Then I expect that the profile field in updateUserInput will be type of updateUserProfileInput but in generated schema I get this type

input updateUserInput {
  id: ID!
  profile: String
}

Is it correct? Is there a way to update both User and it's profile in one mutation?

[epashkov]

Found this #1750 Is it still unsupported?

[iluuu1994]

Are there any workarounds for this? E.g. can I implement the persisting logic manually? This is currently a pretty huge limitation. Multiple requests work, but they are very fragile. Partial failure (one of the N requests fails) makes it impossible to revert to the previous state. The only way around this is de-normalizing my database but that's also a pretty major drawback.

Edit: This can be implemented manually, should've searched the docs before. https://api-platform.com/docs/core/graphql/#custom-mutations Either way, it would be nice if this didn't require manual intervention.

[alanpoulain]

See https://api-platform.com/docs/main/core/graphql/#embedded-relation-input-creation-of-relation-in-mutation for a way to solve this issue.