这是在服务容器中使用依赖项注入的正确方法吗？

Question

So, I have Two different classes:

Class A

class A implements SomeContract
{
    public function extraThicc()
    {
        return 'Filthy Frank';
    } 
}

Class B

class B implements SomeContract
{
    public function extraThicc()
    {
        return 'iDubbbz';
    } 
}

Interface

interface SomeContract
{
    public function extraThicc();
}

Boss Class

class Boss
{
    public $someVar

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

The Service Provider

    $this->app->bind('Boss::class', function($app,$param){
        if ($param['type'] == 'A') return new A();
        if ($param['type'] == 'B') return new B();
    });

The Resolving

public function boss($type)
{
    return app()->makeWith('Boss::class', ['type'=>$type')]);
}

The Facade

class CoolFacade extends Facade
{
    protected static function getFacadeAccessor() { return 'cool'; }
}

The Controller

class StarWarsBattlefrontController extends Controller
{
    public function index()
    {
        return 'Star Wars: Battlefront 2 Loot Boxes are bad, says:'.Cool::Boss('A')->extraThicc();
    }
}

Is there a better method to inject dependencys into the class? Because I don't think this's a good practice to use if statments in the bind method of the Service Provider.

Answer 1

Well, your approach isn't really Dependency Injection, but Facades. If you read Laravel Docs on Facades you can see they just describe them as easy accessor, but they should not be abused. Instead, dependencies must be injected.

For what you need, you might wanna read on Contextual Binding , which would be something like

$this->app->when(BossA::class)
          ->needs(SomeContract::class)
          ->give(function () {
              return new A;
          });

$this->app->when(BossB::class)
          ->needs(SomeContract::class)
          ->give(function () {
              return new B;
          });