Where to bind class implementation in Laravel?

Question

Laravel

I often see such Dependency Injection in projects.

public function __construct(AccountRepository $accountRepo, UserMailer $userMailer, ContactMailer $contactMailer)
    {
        parent::__construct();
        $this->accountRepo = $accountRepo;
        $this->userMailer = $userMailer;
        $this->contactMailer = $contactMailer;
    }

I understand that function variables must be implementations of classes - which are written before them. Where do the variables come from? Like you need to do app::bind()? Or how? I didn't understand something at all.

Answer 1

Create an AccountRepository class. And in this class, write use, indicating the full path to the class file:

use app\Repositories\AccountRepository;
...
class SomeUsefullClassWithConstructorDI {
    public function __construct(AccountRepository $accountRepo, UserMailer $userMailer, ContactMailer $contactMailer)
    {
        parent::__construct();
        $this->accountRepo = $accountRepo;
        $this->userMailer = $userMailer;
        $this->contactMailer = $contactMailer;
    }

DI uses it...

Answer 2

That's right, it's app::bind, but it's better to hang an interface, and for app::bind to prescribe a specific implementation for this contract. Accordingly, to prepare such an object, you need to use app::make, it will resolve itself into the controller.
There is also a model binding
/edit/{user}
for such a binding you need to use Route::model