Lazy Loading Class Properties via Closures

lazy.php

<?php

class view_abstract {

	protected $_data = array();

	public function __get($name) {

		echo "Getting $name\n";
		
		if (is_callable($this->_data[$name])) {

			$this->_data[$name] = $this->_data[$name]->__invoke();

		}

		return $this->_data[$name];

	}

	public function __set($name, $value) {

		echo "Setting $name\n";
		$this->_data[$name] = $value;

	}

}

class controller_abstract {

	public function __construct() {

		$this->view = new view_abstract;

		$this->view->b = function() {

			echo "LOADING SOME DATA OR WHATEVER\n";
			return 1;

		};

	}

}

class g_controller extends controller_abstract {

	public function __construct() {

		echo "Hi I'm " . __CLASS__ . "\n";
		parent::__construct();
		var_dump($this->view->b);

	}

}

class c_controller extends controller_abstract {

	public function __construct() {

		echo "Hi I'm " . __CLASS__ . "\n";
		parent::__construct();

	}

}

new c_controller;
new g_controller;

Output:

» php closure.php
Hi I'm c_controller
Setting b
Hi I'm g_controller
Setting b
Getting b from
LOADING SOME DATA OR WHATEVER
int(1)