Symfony 7.1.7 + API Platform 4.0.8 装饰不存在的"api_platform.listener.request.deserialize"服务报错解决方法

我在用Insomnia测试基于Symfony 7.1.7和API Platform 4.0.8开发的API时，发送请求后遇到了这个错误：

The service "App\EventListener\DeserializeListener" has a dependency on a non-existent service "api_platform.listener.request.deserialize".

我的DeserializeListener.php代码如下：

<?php

namespace App\EventListener;

use ApiPlatform\Symfony\EventListener\DeserializeListener as DecoratedListener;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpKernel\Event\RequestEvent;

class DeserializeListener
{
    public function __construct(private DecoratedListener $decorated)
    {
    }

    public function onKernelRequest(RequestEvent $event): void
    {
        $request = $event->getRequest();
        if($request->isMethodCacheable() || $request->isMethod(Request::METHOD_DELETE))
        {
            return;
        }

        dd($request->getContent());
    }
}

services.yaml中的配置：

services:
    # default configuration for services in *this* file
    _defaults:
        autowire: true      # Automatically injects dependencies in your services.
        autoconfigure: true # Automatically registers your services as commands, event subscribers, etc.

    # makes classes in src/ available to be used as services
    # this creates a service per class whose id is the fully-qualified class name
    App\:
        resource: '../src/'
        exclude:
            - '../src/DependencyInjection/'
            - '../src/Entity/'
            - '../src/Kernel.php'

    # add more service definitions when explicit configuration is needed
    # please note that last definitions always *replace* previous ones
    App\OpenApi\OpenApiFactory:
        decorates: 'api_platform.openapi.factory'
        arguments: ['@App\OpenApi\OpenApiFactory.inner']
        autoconfigure: false

    App\StateProvider\DependenciesStateProvider:
        arguments:
            $rootPath: '%kernel.project_dir%'

    App\StateProcessor\DependenciesStateProcessor:
        arguments:
            $rootPath: '%kernel.project_dir%'

    App\EventListener\DeserializeListener:
        tags:
            - {
                name: 'kernel.event_listener',
                event: 'kernel.request',
                method: 'onKernelRequest',
                priority: 2
            }
        autoconfigure: false
        decorates: 'api_platform.listener.request.deserialize'
        arguments:
            $decorated: '@App\EventListener\DeserializeListener.inner'

我发现用IDE自动补全api_platform.listener.request.deserialize时图标是灰色的，参考的教程版本比较老，试过换decorates的值但不知道选什么，请问该怎么解决这个问题？

问题原因 #

你遇到的问题是因为API Platform 4.0+版本中，反序列化监听器的服务ID已经发生了变化——旧教程里的api_platform.listener.request.deserialize在4.x版本中不再被使用，现在该服务的ID是它的完全限定类名ApiPlatform\Symfony\EventListener\DeserializeListener。

另外你的装饰器代码还有一个小问题：没有调用被装饰服务的原方法，这会导致原本的反序列化逻辑完全不执行，API无法正常处理请求内容。

解决方案 #

1. 修正services.yaml中的装饰配置

把decorates的值替换为API Platform 4.x中反序列化监听器的正确服务ID（即类名），同时可以用@.inner简化被装饰服务的引用：

App\EventListener\DeserializeListener:
    tags:
        - {
            name: 'kernel.event_listener',
            event: 'kernel.request',
            method: 'onKernelRequest',
            priority: 11 # 如果你想在反序列化前执行逻辑，优先级要高于原监听器的10；如果想在之后执行，设为9即可
        }
    autoconfigure: false
    decorates: 'ApiPlatform\Symfony\EventListener\DeserializeListener'
    arguments:
        $decorated: '@.inner'

2. 完善自定义监听器的逻辑

在onKernelRequest方法末尾，调用被装饰服务的原方法，确保原有的反序列化逻辑能正常执行：

<?php

namespace App\EventListener;

use ApiPlatform\Symfony\EventListener\DeserializeListener as DecoratedListener;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpKernel\Event\RequestEvent;

class DeserializeListener
{
    public function __construct(private DecoratedListener $decorated)
    {
    }

    public function onKernelRequest(RequestEvent $event): void
    {
        $request = $event->getRequest();
        if($request->isMethodCacheable() || $request->isMethod(Request::METHOD_DELETE))
        {
            return;
        }

        dd($request->getContent());
        
        // 调用原监听器的方法，保证反序列化逻辑正常运行
        $this->decorated->onKernelRequest($event);
    }
}

3. 验证配置

清理Symfony缓存（php bin/console cache:clear），然后重新用Insomnia测试请求，错误应该会消失，同时你能看到请求内容的调试输出，之后原反序列化逻辑也会正常执行。

备注：内容来源于stack exchange，提问作者user28171371