Laravel中的管道以及使用

管道，就是从一头进，另一头出，常用来处理一批具有先后顺序的连贯的操作，让需要终止管道，只需要返回false。

在Laravel中最常见的管道使用就是中间件了，比如 路由中间件。

对路由中间件的分析参考：https://blog.youkuaiyun.com/raoxiaoya/article/details/103462286

了解了管道的原理之后，我们就可以愉快的使用管道来处理我们的业务了。

比如：我需要对输入的内容做一个处理：增加时间，转化为大写，增加签名。

我们可以为每一个操作定义一个类。

1、定义接口或者契约
app\Services\DataProcessor\DataProcessorInterface.php

<?php

namespace App\Services\DataProcessor;


use Closure;

interface DataProcessorInterface
{
    /**
     * @param $data
     * @param Closure $next
     * @return mixed
     */
    public function handle($data, Closure $next);
}

2、增加时间 的操作
app\Services\DataProcessor\AddPreTime.php

<?php

namespace App\Services\DataProcessor;


use Closure;

class AddPreTime implements DataProcessorInterface
{
    public function handle($data, Closure $next)
    {
        $data['preTime'] = date('Y-m-d H:i:s');

        return $next($data);
    }

}

3、转化为大写 的操作
app\Services\DataProcessor\DataTransfer.php

<?php

namespace App\Services\DataProcessor;


use Closure;
use Illuminate\Support\Str;

class DataTransfer implements DataProcessorInterface
{
    public function handle($data, Closure $next)
    {
        $data['contents'] = Str::upper($data['contents']);

        return $next($data);
    }

}

4、增加签名 的操作
app\Services\DataProcessor\AddEndSignature.php

<?php

namespace App\Services\DataProcessor;


use Closure;
use Illuminate\Support\Str;

class AddEndSignature implements DataProcessorInterface
{
    public function handle($data, Closure $next)
    {
        $data['signature'] = Str::random(10);

        return $next($data);
    }

}

5、调用测试

我们使用 Illuminate\Pipeline\Pipeline 类
then 方法是必须的，传入一个闭包，表示最后会被处理的操作，可以在里面直接返回结果。
vie 方法设置统一调度的方法，默认handle，可以设置。

app\Console\Commands\DemoCommand.php

<?php

namespace App\Console\Commands;

use App\Services\DataProcessor\AddEndSignature;
use App\Services\DataProcessor\AddPreTime;
use App\Services\DataProcessor\DataTransfer;
use Illuminate\Console\Command;
use Illuminate\Pipeline\Pipeline;

class DemoCommand extends Command
{
    /**
     * The name and signature of the console command.
     *
     * @var string
     */
    protected $signature = 'DemoCommand';

    /**
     * The console command description.
     *
     * @var string
     */
    protected $description = 'DemoCommand';

    /**
     * Create a new command instance.
     *
     * @return void
     */
    public function __construct()
    {
        parent::__construct();
    }

    /**
     * Execute the console command.
     *
     * @return mixed
     */
    public function handle()
    {
        $pipes = [
            AddPreTime::class,
            DataTransfer::class,
            AddEndSignature::class,
        ];

        $data = ['contents'=>'asdhbybopwertyuip'];

        $result = app(Pipeline::class)
            ->send($data)
            ->through($pipes)
            ->via('handle')
            ->then(function ($datas) {
                return $datas;
            });

        $this->info(print_r($result, true));
    }
}

别忘了注册到kernel.php

php artisan DemoCommand

打印结果：

Array
(
    [contents] => ASDHBYBOPWERTYUIP
    [preTime] => 2020-01-07 07:55:33
    [signature] => xgqohTzlMq
)

当然实现同样的效果的方式很多，比如：观察者模式。