How to Auto Inject Dependency with Laravel - php

Question

I'm trying to build a structure that uses dependency injection on lumen.
I Have a Service Layer and repository layer.
I want to inject the repository layer to service layer. Let me try to show you the code
interface IUserRepostitory {
public function getByID($id);
}
class UserRepository extends BaseRepository implements IRepository{
public function getByID($id) {
//Please don't think how this function works, my question about dependency injection
return $this->findOrFail($id);
}
}
interface IService {
public function getByID($id);
}
class UserService implements IService{
private $Repository;
public __construct(IUserRepositor $UserRepository) {
$this->Repository = $UserRepository
}
public function getByID($id) {
return $this->Repository->getByID($id);
}
}
Here I'm registering the dependency resolver.
//Dependency resolver for Repository Layer
class RepositoryServiceProvider extends ServiceProvider {
public function register()
{
$this->app->singleton(IUserRepository::class, function () {
return new UserRepository();
});
}
}
Here I'm registering Service Layer
class ServiceServiceProvider extends ServiceProvider {
public function register()
{
$this->app->singleton(IUserService::class, function () {
//Here is what I don't like
//It would be great a solution that automaticly resolve UserRepository.
return new UserService(new UserRepository());
});
}
}
As you see, I want to auto resolve the dependency into UserService. But singleton method need to create the returning object.
Is there a better way for this?
*** note : please don't pay attention on syntax, I'm writing it on lumen but the same problem on laravel.

Answer 1

Once you bind the UserRepository to the IUserRepository, you may then instantiate the IUserService with the IUserRepository by resolving with the make function!
Modifying your ServiceServiceProvider as such:
class ServiceServiceProvider extends ServiceProvider
{
public function register()
{
$this->app->singleton(IUserService::class, function ($app) {
return new UserService($app->make(IUserRepository::class));
});
}
}