Slick Dependency Injection¶

slick/di is an easy dependency injection container for PHP 5.5+. It aims to be very lightweight and tries to remove a lot of the guessing and magic stuff that dependency containers use those days. It also allows you to nest containers witch can become very useful if you have several packages that you reuse in your applications, allowing you to define containers with default dependencies in those packages overriding and using them in your application.

There are a lot of implementations of a dependency injection container out there and some of them are really good. Some examples are the Symfony Dependency Injection Component, Zend 2 Dependency Injection, The PHP league container, or PHP-DI just to name a few.

Dependency injection container quick start¶

To create a dependency container lets create a services.php file with all our dependency definitions:

use Slick\Configuration\Configuration:
use Slick\Di\Definition\ObjectDefinition;

/**
 * Dependency injection object definition example
 */
return [
    'config' => function() {
        return Configuration::get('config');
    },
    Engine::class => ObjectDefinition::create(Engine::class)
        ->setConstructArgs(['@config'])
        ->setMethod('setMode', ['simple'])
];

Create a dependency container with ContainerBuilder:

use Slick\Di\ContainerBuilder;

$container = (new ContainerBuilder(__DIR__ . '/services.php'))->getContainer();

Now you are ready to create and inject dependencies with your container:

class Car
{
    /**
     * @var Engine
     */
    protected $engine;

    public function __construct(Engine $engine)
    {
        $this->engine = $engine;
    }
}

$myCar = $container->get(Car::class);

That’s it!

Slick Dependency Injection¶

Dependency injection container quick start¶

User guide¶