Laravel 12 イベントとリスナー完全ガイド：イベント駆動アーキテクチャの実装と面接対策

<?php

namespace App\Listeners;

use App\Events\OrderShipped;

class SendOrderConfirmation
{
    public function handle(OrderShipped $event): void
    {
        // $event->order->user に確認メールを送信
    }
}

# イベントクラスを生成
php artisan make:event OrderShipped

# イベントに紐づくリスナーを生成
php artisan make:listener SendShipmentNotification --event=OrderShipped

<?php

namespace App\Events;

use App\Models\Order;
use Illuminate\Foundation\Events\Dispatchable;
use Illuminate\Broadcasting\InteractsWithSockets;
use Illuminate\Queue\SerializesModels;

class OrderShipped
{
    use Dispatchable, InteractsWithSockets, SerializesModels;

    public function __construct(
        public Order $order,
    ) {}
}

<?php

namespace App\Http\Controllers;

use App\Events\OrderShipped;
use App\Models\Order;
use Illuminate\Http\Request;

class OrderController extends Controller
{
    public function ship(Request $request, Order $order)
    {
        // 出荷処理...
        
        OrderShipped::dispatch($order);
        
        return redirect()->route('orders.index');
    }
}

// 追跡番号がある場合のみ発火
OrderShipped::dispatchIf($order->tracking_number !== null, $order);

<?php

namespace App\Listeners;

use App\Events\OrderShipped;
use Illuminate\Contracts\Queue\ShouldQueue;

class SendShipmentNotification implements ShouldQueue
{
    public $queue = 'notifications';
    public $delay = 60; // 処理前に60秒待機

    public function handle(OrderShipped $event): void
    {
        // $event->order->user に通知を送信
    }
}

public function viaConnection(): string
{
    return 'redis';
}

public function viaQueue(): string
{
    return $this->event->order->priority === 'high' 
        ? 'high-priority' 
        : 'default';
}

public function shouldQueue(OrderShipped $event): bool
{
    // 100ドル以上の注文のみキューに入れる
    return $event->order->total >= 10000;
}

'connections' => [
    'redis' => [
        'after_commit' => true,
    ],
],

use Illuminate\Contracts\Queue\ShouldQueueAfterCommit;

class UpdateInventory implements ShouldQueueAfterCommit
{
    public function handle(OrderShipped $event): void
    {
        // 注文のクエリは安全、トランザクションはコミット済み
    }
}

use Illuminate\Contracts\Events\ShouldDispatchAfterCommit;

class OrderShipped implements ShouldDispatchAfterCommit
{
    // トランザクションコミット後にのみイベントが発火
}

use Illuminate\Contracts\Queue\ShouldBeUnique;
use Illuminate\Contracts\Queue\ShouldQueue;

class ProcessLicenseKey implements ShouldQueue, ShouldBeUnique
{
    public $uniqueFor = 3600; // ロックは1時間後に期限切れ

    public function uniqueId(LicensePurchased $event): string
    {
        return 'license:' . $event->license->id;
    }

    public function handle(LicensePurchased $event): void
    {
        // ライセンスキーを生成して割り当て
    }
}

<?php

namespace App\Listeners;

use Illuminate\Auth\Events\Login;
use Illuminate\Auth\Events\Logout;
use Illuminate\Events\Dispatcher;

class UserActivitySubscriber
{
    public function handleLogin(Login $event): void
    {
        // ログイン成功をログに記録、last_loginタイムスタンプを更新
    }

    public function handleLogout(Logout $event): void
    {
        // ログアウトをログに記録、セッションデータをクリア
    }

    public function subscribe(Dispatcher $events): array
    {
        return [
            Login::class => 'handleLogin',
            Logout::class => 'handleLogout',
        ];
    }
}

public function handle(OrderShipped|OrderCancelled $event): void
{
    match (true) {
        $event instanceof OrderShipped => $this->notifyShipped($event),
        $event instanceof OrderCancelled => $this->notifyCancelled($event),
    };
}

use Illuminate\Support\Facades\Event;

Event::defer(function () {
    $user = User::create(['name' => 'John']);
    $user->posts()->create(['title' => 'Welcome']);
});
// UserとPostの作成イベントがここで発火