robertogallea / service-container

Example of PHP Service Container

Service Container example

This is an example of a Service Container PHP implementation providing the following features:

• Bind a concrete implementation to an abstract implementation

$container->bind(AbstractClass::class, ConcreteClass::class);
var_dump($container->resolve(AbstractClass::class)); // ConcreteClass::class 

• Bind a singleton object to an abstract implementation

$container->singleton(AbstractClass::class, ConcreteClass::class);
$implementation1 = $container->resolve(AbstractClass::class);
$implementation2 = $container->resolve(AbstractClass::class);
echo ($implementation1 === $implementation2); // true

• Bind a callable (closure or invokable class) to an abstract implementation

$container->bind(AbstractClass::class, function ($container) {
  return 'hi there!';
});
var_dump($container->resolve(AbstractClass::class)); // 'hi there!'

• Recursive dependency resolution

class AClassWithDependencies
{
    public function __construct(public AClass $dependency)
    {

    }
}

class AClass
{

}

...

$container->bind(AbstractClass::class, AClassWithDependencies::class);
$instance = $container->resolve(AbstractClass::class);
// make an instance of AClassWithDependencies, built by recursively building its constructor 
// dependencies (i.e. AClass)