Container

A lightweight dependency injection container implementing PSR-11.

Installation

composer require georgeff/container

Usage

Registering Definitions

Register a definition by providing an ID and a callable factory. The container instance is passed to the factory.

use Georgeff\Container\Container;

$container = new Container();

$container->add('database', function (Container $container) {
    return new DatabaseConnection('localhost', 'mydb');
});

Shared Definitions

Shared definitions are resolved once and the same instance is returned on subsequent calls.

$container->addShared('database', function (Container $container) {
    return new DatabaseConnection('localhost', 'mydb');
});

// Or pass true as the third argument to add()
$container->add('database', function (Container $container) {
    return new DatabaseConnection('localhost', 'mydb');
}, true);

Resolving Definitions

$db = $container->get('database');

Aliases

Aliases allow you to resolve a definition by an alternate name, useful for binding interfaces to implementations.

$container->addShared(DatabaseConnection::class, function (Container $container) {
    return new DatabaseConnection('localhost', 'mydb');
});

$container->addAlias(DatabaseConnection::class, ConnectionInterface::class);

// Resolves the DatabaseConnection definition
$db = $container->get(ConnectionInterface::class);

Checking for Definitions

$container->has('database');    // true
$container->has('nonexistent'); // false

Exceptions

• DefinitionNotFoundException — thrown when getting a definition that does not exist or aliasing a non-existing definition. Implements PSR-11 NotFoundExceptionInterface.
• CircularDependencyException — thrown when a circular dependency is detected during resolution. Implements PSR-11 ContainerExceptionInterface.
• ContainerException — thrown when an error occurs during definition resolution. Implements PSR-11 ContainerExceptionInterface.

License

MIT