Picotainer

This package contains a really minimalist dependency injection container (24 lines of code!) compatible with container-interop (supports ContainerInterface and delegate lookup feature). It is also, therefore, compatible with PSR-11, the FIG container standard.

Picotainer is heavily influenced by the Pimple DI container. Think about it as a Pimple container with even less features, and ContainerInterop compatibility.

Installation

Before using Picotainer in your project, add it to your composer.json file:

$ ./composer.phar require mouf/picotainer ~1.0

Storing entries in the container

Creating a container is a matter of creating a Picotainer instance. The Picotainer class takes 2 parameters:

• the list of entries, as an array of anonymous functions
• an optional delegate-lookup container

use Mouf\Picotainer\Picotainer;
use Psr\Container\ContainerInterface;

$container = new Picotainer([
	"myInstance"=>function(ContainerInterface $container) {
		return new MyInstance();
	},
	"myOtherInstance"=>function(ContainerInterface $container) {
		return new MyOtherInstance($container->get('myInstance'));
	}
	"myParameter"=>function(ContainerInterface $container) {
		return MY_CONSTANT;
	}
], $rootContainer);

The list of entries is an associative array.

• The key is the name of the entry in the container
• The value is an anonymous function that will return the entry

The entry can be anything (an object, a scalar value, a resource, etc...)

The anonymous function must accept one parameter: the container on which dependencies will be fetched. The container is the "delegate-lookup container" if it was passed as the second argument of the constructor, or the Picotainer instance itself if no delegate lookup container was passed.

Fetching entries from the container

Fetching entries from the container is as simple as calling the get method:

$myInstance = $container->get('myInstance');

Why the need for this package?

This package is part of a long-term effort to bring interoperability between DI containers. The ultimate goal is to make sure that multiple containers can communicate together by sharing entries (one container might use an entry from another container, etc...)