Extensible DI container for Symfony2

This package contains an ExtensibleContainer class that extends the Container class of Symfony 2. The extended class will let you add additional dependency injection containers (DIC) to Symfony 2's container.

This means that when you develop a Symfony 2 application, you are no more forced into using Symfony's DIC only. You can now use add any DIC you want!

How does it work?

To make this work, you must put the Symfony2 container inside a composite container that will contain other containers. There is a great implementation of a CompositeContainer in the Acclimate projet.

The typical workflow will look like this:

The router (or any other component) will ask for an instance to the ExtensibleContainer. The ExtensibleContainer will forward the call to the CompositeContainer that will in turn forward the call to any other container in the CompositeContainer. To enter the CompositeContainer, a container must respect the ContainerInterface as defined in the container-interop project.

Installation

The ExtensibleContainer is distributed as a Composer package. You will also typically need Acclimate (for the composite container) and other containers.

{
	// Let's replace container-interop as long as the ParentAwareContainerInterface is not adopted:
	"repositories" : [
		{
			"type" : "vcs",
			"url" : "[email protected]:moufmouf/container-interop.git"
		}
	],
	require: {
		... the dependencies to Symfony go here ...
		"mouf/interop.symfony.di" : "2.3.*",
		"acclimate/container" : "~1.0",
		// As long as the ParentAwareContainerInterface is not adopted by container-interop, you need this:
		"container-interop/container-interop" : "dev-parentaware as 1.0.0",
		// You will also need dependencies to the containers you want to use, for instance:
		"mouf/mouf" : "~2.0"
	}
}

In your app/AppKernel.php file, add these 2 methods:

...

class AppKernel extends Kernel {
	...
	
	/**
	 * Gets the container's base class.
	 * We use this to make Symfony use the ExtensibleContainer.
	 *
	 * @return string
	 */
	protected function getContainerBaseClass()
	{
		return 'Mouf\\Symfony\\Component\\DependencyInjection\\ExtensibleContainer';
	}
	
	/**
	 * Initializes the service container.
	 *
	 * Use this method to initialize your own DI container and register it
	 * in Symfony DI container.
	 */
	protected function initializeContainer()
	{
		parent::initializeContainer();
	    	
		// Here, you can access the Symfony container using $this->container and register
		// your own container in it.
	
		$compositeContainer = new CompositeContainer();

		// The SF2 container does not implement the ContainerInterface interface
		// Therefore, it needs to be "acclimated".
    	$acclimator = new ContainerAcclimator();
    	$sfContainer = $this->container;
    	$sfContainer->setParentContainer($compositeContainer);
    	$acclimatedSfContainer = $acclimator->acclimate($this->container);
    	
    	$compositeContainer->addContainer($acclimatedSfContainer);
    	
    	// Now, let's add other containers.
    	// They must implement the ContainerInterface (and optionnally the ParentAwareContainerInterface)
    	$compositeContainer->addContainer(MoufManager::getMoufManager());
	}
}

Your DI container must respect the ContainerInterface provided by the container-interop project.

What DI containers can I plug in Symfony?

Out of the box, you can plug these DI containers, because they respect the ContainerInterface interface:

• Mouf2 (http://mouf-php.com)
• PHP-DI 4.1+ (https://github.com/auraphp/Aura.Di)
• PimpleInterop (https://github.com/moufmouf/pimple-interop, a wrapper around Pimple)

But wait! Thanks to Jeremy Lindblom and its awesome Acclimate package, you can now take almost any dependency injection container out there, and get an adapter on that container that respects the ContainerInterface interface.