README

监听延迟事件，并在所有事务完成后触发它们。

要求

• PHP: ^5.5 || ^7.0
• Laravel: ^5.4

安装

composer require mpyw/laravel-transaction-observer:^1.0

基本用法

注册服务提供者。

config/app.php:

        /*
         * Package Service Providers...
         */
        mpyw\LaravelTransactionObserver\Provider::class,

就这么多。现在你可以分发以回调作为第一个参数的 DelayedCall。

public mpyw\LaravelTransactionObserver\Events\DelayedCall::__construct(callable $callback)
public void mpyw\LaravelTransactionObserver\Events\DelayedCall::fire()

注意，回调是

• 在所有事务完成后触发的。
• 如果当前事务失败则取消。

/**
 * Example: Handling callbacks for counter caching
 */

use mpyw\LaravelTransactionObserver\Events\DelayedCall;

DB::transaction(function () {

    $post = Post::create([
        'text' => 'This is main text',
        'comment_count' => 0,
    ]);

    DB::transaction(function () use ($post) {
        $comment = new Comment(['text' => 'This is first comment']);
        $comment->post()->associate($post);
        $comment->save();

        event(new DelayedCall(function () use ($post) {
            ++$post->comment_count; // A: Increment counter cache!
        }));
    });

    DB::transaction(function () use ($post) {
        $comment = new Comment(['text' => 'This is second comment']);
        $comment->post()->associate($post);
        $comment->save();

        event(new DelayedCall(function () use ($post) {
            ++$post->comment_count; // B: Increment counter cache!
        }));

        throw new \RuntimeException('Oops!');
    });
});

// A fires here, while B never do.

高级用法：准备自定义事件类

1. 创建一个实现 DelayedEvent 的类。

app/Events/MyDelayedEvent.php:

<?php

namespace App\Events;

use mpyw\LaravelTransactionObserver\Contracts\DelayedEvent;

class MyDelayedEvent implements DelayedEvent
{
    protected $payload;

    public function __construct($payload)
    {
        $this->payload = $payload;
    }

    public function fire()
    {
        ($this->payload)();
    }
}

2. 在你的应用程序服务提供者中监听它。

app/Providers/AppServiceProvider.php:

<?php

namespace App\Providers;

use Illuminate\Support\ServiceProvider;
use mpyw\LaravelTransactionObserver\Facades\TransactionObserver;
use App\Events\MyDelayedEvent;

class AppServiceProvider extends ServiceProvider
{
    /**
     * Register any application services.
     *
     * @return void
     */
    public function register()
    {
        //
    }

    /**
     * Bootstrap any application services.
     *
     * @return void
     */
    public function boot()
    {
        TransactionObserver::listen(MyDelayedEvent::class);
    }
}

相关包

• mpyw/laravel-delayed-counter-cache: 延迟计数器缓存，在事务外递增/递减