API Platform 2.7 GraphQL自定义Query无法指定Output类型求助

问题原因 #

在API Platform 2.7中，为实体（如User）的ApiResource添加GraphQL自定义Query时，框架会默认将Query与该实体类型关联，即使设置了output参数也可能被覆盖；同时如果目标Output类未被标记为GraphQL可识别类型，也会导致返回类型不生效。

解决方案 #

1. 标记Output类为GraphQL类型 #

确保MyFullPerimeterOutput被API Platform识别为GraphQL类型，添加#[GraphQLType]注解：

<?php
namespace App\Dto;

use ApiPlatform\Metadata\GraphQL\GraphQLType;
use Symfony\Component\Serializer\Annotation\Groups;

#[GraphQLType(name: 'MyFullPerimeterOutput')]
class MyFullPerimeterOutput
{
    #[Groups(['user_my_full_perimeter'])]
    public string $username;

    #[Groups(['user_my_full_perimeter'])]
    public array $permissions;

    // 其他业务字段...
}

2. 修正GraphQL Query配置 #

在User的ApiResource中定义Query时，显式指定type参数覆盖默认的实体关联，同时确保output参数正确设置：

new Query(
    name: 'myFullPerimeter',
    security: "is_granted('ROLE_USER')",
    output: MyFullPerimeterOutput::class,
    type: MyFullPerimeterOutput::class, // 显式指定返回的GraphQL类型
    normalizationContext: ['groups' => ['user_my_full_perimeter']],
    provider: UserProvider::class
),

3. 确保Provider返回Output实例 #

修改UserProvider，使其返回MyFullPerimeterOutput实例而非User实体：

<?php
namespace App\Provider;

use ApiPlatform\Metadata\Operation;
use ApiPlatform\State\ProviderInterface;
use App\Dto\MyFullPerimeterOutput;
use Symfony\Component\Security\Core\Security;

class UserProvider implements ProviderInterface
{
    public function __construct(private Security $security) {}

    public function provide(Operation $operation, array $uriVariables = [], array $context = []): MyFullPerimeterOutput
    {
        $currentUser = $this->security->getUser();
        
        $output = new MyFullPerimeterOutput();
        $output->username = $currentUser->getUsername();
        $output->permissions = $currentUser->getPermissions();
        // 填充其他字段逻辑...

        return $output;
    }
}

替代方案：独立定义Output的ApiResource #

如果不想将Query关联到User实体，可以直接为MyFullPerimeterOutput创建ApiResource，这样生成的Query会直接返回目标类型：

<?php
namespace App\Dto;

use ApiPlatform\Metadata\ApiResource;
use ApiPlatform\Metadata\GraphQL\Query;
use App\Provider\UserProvider;

#[ApiResource(
    graphql: [
        new Query(
            name: 'myFullPerimeter',
            security: "is_granted('ROLE_USER')",
            normalizationContext: ['groups' => ['user_my_full_perimeter']],
            provider: UserProvider::class
        )
    ]
)]
#[GraphQLType(name: 'MyFullPerimeterOutput')]
class MyFullPerimeterOutput
{
    // 字段定义...
}

验证 #

修改完成后，清除API Platform缓存（php bin/console cache:clear），打开GraphQL Playground即可看到myFullPerimeter查询返回的是MyFullPerimeterOutput类型。

内容的提问来源于stack exchange，提问作者Maxime TUAL