Delegate Containers

Introduction

Delegate containers are a way to allow you to register one or multiple backup containers that will be used to attempt the resolution of services when they cannot be resolved via this container.

Usage

A delegate must be a PSR-11 implementation and can be registered using the delegate method.

<?php 

declare(strict_types=1);

namespace Acme\Container;

use Psr\Container\ContainerInterface;

class DelegateContainer implements ContainerInterface
{
    // ..
}

<?php 

declare(strict_types=1);

$container = new League\Container\Container();
$delegate  = new Acme\Container\DelegateContainer();

// this method can be invoked multiple times, each delegate
// is checked in the order that it was registered
$container->delegate($delegate);

Now that the delegate has been registered, if a service cannot be resolved via the primary container, it will resort to the has and get methods of the delegates to resolve the requested service.