<?php
/* $Id$ */
namespace Mammut\Util;

(defined('MAMMUT') && (basename(__FILE__) != basename($_SERVER['PHP_SELF']))) or die('ACCESS DENIED');

/**
 * Lazy loading utility class.
 *
 * The class uses a lamda function to fetch the value, but only on a request to read the
 * value via the get method.
 *
 * @author Stefan Daurer <s.daurer@q-spot.org>
 * @package Mammut\Util
 */
class LazyLoader extends \Mammut\StdObject {
	private $instance = NULL;
	private $known = false;
	private $initFunc;
	private $param = false;

	/**
	 * Creates a new helper instance
	 *
	 * @param \Closure $initFunc
	 *        	the function which creates the new object
	 */
	public function __construct(\Closure $initFunc) {
		$this->initFunc = $initFunc;
	}

	public function setParam(array $p) {
		$this->param = $p;
	}

	public function getParam() {
		return $this->param;
	}

	/**
	 * Receives the value.
	 * Calles the defined function if the current known value is unknown.
	 *
	 * @return mixed the result of the function call
	 */
	public function get() {
		if(!$this->known) {
			$f = $this->initFunc;
			$this->instance = ($this->param) ? $f($this->param) : $f();
			$this->known = true;
		}
		return $this->instance;
	}

	/**
	 * Removes the known value and forces the fetch with a function call
	 */
	public function clear() {
		$this->instance = NULL;
		$this->known = false;
	}
}