如何有效控制Laravel/Lumen事件监听器传播（尤其在队列场景下）

// app/Providers/EventServiceProvider.php
protected $listen = [
    \App\Events\RegisterUserEvent::class => [
        \App\Listeners\StoreUserListener::class,
        \App\Listeners\SendVerificationEmailListener::class,
    ],
];

// app/Listeners/StoreUserListener.php
namespace App\Listeners;

use App\Events\RegisterUserEvent;
use Exception;

class StoreUserListener
{
    public function handle(RegisterUserEvent $event): bool
    {
        try {
            // 尝试存储用户数据
            $user = \App\Models\User::create([
                'name' => $event->name,
                'email' => $event->email,
                // ... 其他数据
            ]);

            if (!$user) {
                throw new Exception("Error storing user data.");
            }

            // 如果成功，返回 true 或不返回任何值（默认继续传播）
            return true; 

        } catch (Exception $e) {
            // 如果发生错误，阻止事件传播
            \Log::error("Failed to store user: " . $e->getMessage());
            return false; // 返回 false 停止传播
        }
    }
}

// app/Listeners/SendVerificationEmailListener.php
namespace App\Listeners;

use App\Events\RegisterUserEvent;

class SendVerificationEmailListener
{
    public function handle(RegisterUserEvent $event)
    {
        // 如果 StoreUserListener 返回 false，这个监听器将不会被执行
        \Mail::to($event->email)->send(new \App\Mail\VerifyEmail());
        \Log::info("Verification email sent to " . $event->email);
    }
}

// app/Providers/EventServiceProvider.php (保持不变，或调整为更细粒度的事件)
protected $listen = [
    \App\Events\RegisterUserEvent::class => [
        \App\Listeners\StoreUserListener::class,
    ],
    \App\Events\UserStoredEvent::class => [ // 新增事件
        \App\Listeners\SendVerificationEmailListener::class,
    ],
];

// app/Listeners/StoreUserListener.php
namespace App\Listeners;

use App\Events\RegisterUserEvent;
use App\Events\UserStoredEvent; // 引入新事件
use Exception;

class StoreUserListener
{
    public function handle(RegisterUserEvent $event)
    {
        try {
            $user = \App\Models\User::create([
                'name' => $event->name,
                'email' => $event->email,
            ]);

            if (!$user) {
                throw new Exception("Error storing user data.");
            }

            // 用户存储成功后，派发 UserStoredEvent
            event(new UserStoredEvent($user)); // 传递必要数据
            \Log::info("User stored successfully: " . $user->email);

        } catch (Exception $e) {
            \Log::error("Failed to store user: " . $e->getMessage());
            // 失败时，不派发 UserStoredEvent，后续逻辑自然不会触发
        }
    }
}

// app/Listeners/SendVerificationEmailListener.php
namespace App\Listeners;

use App\Events\UserStoredEvent; // 监听新事件

class SendVerificationEmailListener
{
    public function handle(UserStoredEvent $event)
    {
        // 只有当 UserStoredEvent 被派发时，此监听器才会被执行
        \Mail::to($event->user->email)->send(new \App\Mail\VerifyEmail());
        \Log::info("Verification email sent to " . $event->user->email);
    }
}

// app/Providers/EventServiceProvider.php
protected $listen = [
    \App\Events\RegisterUserEvent::class => [
        \App\Listeners\RegisterUserWorkflowListener::class, // 只有一个监听器
    ],
];

// app/Listeners/RegisterUserWorkflowListener.php
namespace App\Listeners;

use App\Events\RegisterUserEvent;
use Exception;

class RegisterUserWorkflowListener
{
    public function handle(RegisterUserEvent $event)
    {
        try {
            // 步骤 1: 存储用户
            $user = \App\Models\User::create([
                'name' => $event->name,
                'email' => $event->email,
            ]);

            if (!$user) {
                throw new Exception("Error storing user data.");
            }

            \Log::info("User stored successfully: " . $user->email);

            // 步骤 2: 发送验证邮件 (只有在步骤 1 成功后才执行)
            \Mail::to($event->email)->send(new \App\Mail\VerifyEmail());
            \Log::info("Verification email sent to " . $event->email);

        } catch (Exception $e) {
            \Log::error("Failed to complete user registration workflow: " . $e->getMessage());
            // 任何一步失败，整个流程停止，并记录错误
        }
    }
}

// 定义事件时，确保属性可写入
class RegisterUserEvent
{
    use Dispatchable, InteractsWithSockets, SerializesModels;

    public $name;
    public $email;
    public $userStored = false; // 添加状态标志

    public function __construct(string $name, string $email)
    {
        $this->name = $name;
        $this->email = $email;
    }
}

// StoreUserListener
class StoreUserListener
{
    public function handle(RegisterUserEvent $event)
    {
        try {
            $user = \App\Models\User::create(['name' => $event->name, 'email' => $event->email]);
            if ($user) {
                $event->userStored = true; // 更新事件状态
            }
        } catch (Exception $e) {
            // 记录错误
        }
    }
}

// SendVerificationEmailListener
class SendVerificationEmailListener
{
    public function handle(RegisterUserEvent $event)
    {
        if ($event->userStored) { // 检查事件状态
            \Mail::to($event->email)->send(new \App\Mail\VerifyEmail());
        } else {
            \Log::warning("Verification email not sent for " . $event->email . " as user was not stored.");
        }
    }
}