Constructors and Initialization

The base class in li3's hierarchy, lithium\core\Object, forms the basic logic for all of the concrete classes in the framework. This class defines several conventions for how classes in li3 should be structured:

• Universal constructor
• Object configuration
• Object initialization
• Filtering
• Testing utilities

Universal Constructor

The Object class features a unified constructor, which all classes share. The function takes a single argument, $config which is an array of properties that is automatically saved to the $_config property of the current object. This approach allows for short constructor signatures and creates a unified way to override object configuration, or set object defaults when subclassing.

Object Configuration & Initialization

Constructor logic should be kept to a minimum. One of the last steps in the unified constructor is to call the objects init() method. Here's where you do your heavy lifting.

If you need to manipulate an object in its un-initialized state, pass false as the value to the init key to the constructor. This prevents init() from running, and is especially handy when building test cases.

namespace app/extensions;

use lithium\net\http\Service;

class Foo extends \lithium\core\Object {
	public $service;

	public function __construct(array $config = []) {
		$defaults = [
			'foo' => 'bar'
		];
		parent::__construct($config + $defaults);
	}

	public function _init() {
		parent::_init();
		$this->service = new Service();
	}

	public function baz() {
		echo $this->_config['foo'];
	}
}

use app\extensions\Foo;

$foo = new Foo();
$foo->baz();               // 'bar'

$foo2 = new Foo([
	'foo' => '123'
]);
$foo2->baz();              // '123'

$foo3 = new Foo([
	'init' => 'false'
]);
get_class($foo3->service);  // PHP Warning...
get_class($foo->service);  // 'lithium\net\http\Service'