php - Laravel 编写接口(interface)的最佳方式

Question

我需要有关此方法的建议以编写接口(interface)。

场景:我需要实现一个虚拟类 ImageUploader 然后在构造函数上接收一个接口(interface)并将图像保存在我的目录中。这是出于学习目的，所以如果我以正确的方式进行操作，我需要您的建议:

这是我在 Laravel 5.3 框架上的实现:

1:实现的虚拟接口(interface)，因此我可以创建不同的方式来存储我的图像

//dummy interface

namespace App\Lib\ImageUploader\Drivers;

interface ImageInterface
{
   public function hello();
}

2:这里有两个实现我的接口(interface)的驱动程序。每个都有自己的方法hello(在现实生活中，例如每个类可能有自己的保存方法用于任何类型的驱动程序)

// Avatar Driver Class

namespace App\Lib\ImageUploader\Drivers;

class AvatarImage implements ImageInterface
{
     public function hello()
     {
          return 'I am a AvatarImage';
     }
}

还有一个类，例如BackgroundImage可以保存用户上传图片的桌面版和移动版:

// Background Driver Class


namespace App\Lib\ImageUploader\Drivers;

class BackgroundImage implements ImageInterface
{
   public function hello()
   {
     // this is a dummy method, in real life this class will save 2 images (desktop + mobile)
     return 'I am a BackgroundImage';
   }

}

这是我的 ImageUploader 类，具有“Programming to interface”策略:

// ImageUploader.php
// this class will implement all methods that I need for manage saving operations

namespace App\Lib\ImageUploader;
use App\Lib\ImageUploader\Drivers\ImageInterface;


class ImageUploader
{

   protected $driver;

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

   public function save()
   {
      return  $this->driver->hello();
   }
}

现在我创建自己的 Laravel 框架服务提供者:

namespace App\Providers;

use App\Lib\ImageUploader\Drivers\AvatarImage;
use App\Lib\ImageUploader\Drivers\BackgroundImage;
use App\Lib\ImageUploader\ImageUploader;
use Illuminate\Support\ServiceProvider;

class ImageUploadServiceProvider extends ServiceProvider
{
    /**
    * Bootstrap the application services.
    *
    * @return void
    */
    public function boot()
   {
     //
   }

    /**
    * Register the application services.
    *
    * @return void
    */

    public function register()
    {
       $this->registerAvatar();
       $this->registerBackground();
    }

    protected function registerAvatar(){
       $this->app->bind('AvatarUploader', function () {
          return new ImageUploader(new AvatarImage());
       });
    }

    protected function registerBackground(){
       $this->app->bind('BackgroundUploader', function () {
         return new ImageUploader(new BackgroundImage());
       });
    }
}

最后，我尝试在我的 Controller 中使用我的类，例如当用户尝试上传您的头像图片或新背景图片时:

// this will produce "I am a AvatarImage" in real life this line create thumbnail and will save my image in my local directory

public function store(Request $request){
    (App::make('AvatarUploader'))->save();   
}

有更好的方法吗？对我的实现有什么建议吗？

Answer 1

看看https://laravel.com/docs/5.3/container#binding-interfaces-to-implementations和 https://laravel.com/docs/5.3/container#contextual-binding .

因此在您的服务提供者逻辑中，您可以指定 -

$this->app->when(AvatarController::class)
          ->needs(ImageInterface::class)
          ->give(function () {
              return new AvatarUploader();
          });

$this->app->when(BackgroundController::class)
          ->needs(ImageInterface::class)
          ->give(function () {
              return new BackgroundImage();
          });

然后在您的 Controller 或其他类中，只需依赖注入(inject) ImageInterface 接口(interface)而不是具体类。

class AvatarController extends Controller
{
    protected $imageInterface;
    public function __construct(ImageInterface $imageInterface)
    {
        $this->imageInterface = $imageInterface;
    }

    public function store()
    {
        return $this->imageInterface->hello(); // returns "I am an Avatar Image"
    }
}

class BackgroundController extends Controller
{
    protected $imageInterface;
    public function __construct(ImageInterface $imageInterface)
    {
        $this->imageInterface = $imageInterface;
    }

    public function store()
    {
        return $this->imageInterface->hello(); // returns "I am a Background Image"
    }
}