<?php // vim:ts=4:sw=4:noet
/*====================================================================== 
Copyright (C) 2006-2009, Walter Doekes
This file is part of KjwLib-php45.
 
KjwLib-php45 is free software: you can redistribute it and/or modify 
it under the terms of the GNU General Public License as published by 
the Free Software Foundation, either version 3 of the License, or 
(at your option) any later version. 

KjwLib-php45 is distributed in the hope that it will be useful, 
but WITHOUT ANY WARRANTY; without even the implied warranty of 
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
GNU General Public License for more details. 

You should have received a copy of the GNU General Public License 
along with KjwLib-php45.  If not, see <http://www.gnu.org/licenses/>. 
======================================================================*/

/**
 * KjwUtil contains various static methods.
 *
 * @note Unused.
 */
class KjwUtil {
	/**
	 * Get a singleton instance.
	 *
	 * You call your singleton class like this:
	 * $theClassInstance = &KjwSingleton::getInstance("ClassName"[, optional arguments]);
	 * @param $className The name of the class. If not included yet,
	 *   this should be the same as the filename.
	 * @param ... Optional arguments to the constructor.
	 * @note Make sure you use case sensitive names! PHPs case-insensitivity might cause problems.
	 * @note You can't pass variables by reference, due to the way PHP4 func_get_args works.
	 *   If you want references, hand them to the instance afterwards.
	 */
	function &getSingleton($className) {
		static $instances = array();  // array of instance names
		assert(is_string($className));
		if (!array_key_exists($className, $instances)) {
			// instance does not exist, so create it
			if (file_exists(dirname(__FILE__) . "/$className.php"))
				require_once(dirname(__FILE__) . "/$className.php");
			// * call_user_func doesn't let me create new objects.., that's not cool
			//   so, no call_user_func here
			// * func_get_args() returns the variables by value, instead of by reference
			//   so, if you want to pass references, you're out of luck :(
			$a = &func_get_args();
			switch (func_num_args() - 1) {
			case 0: $instances[$className] = new $className(); break;
			case 1: $instances[$className] = new $className(&$a[1]); break;
			case 2: $instances[$className] = new $className(&$a[1],&$a[2]); break;
			case 3: $instances[$className] = new $className(&$a[1],&$a[2],&$a[3]); break;
			case 4: $instances[$className] = new $className(&$a[1],&$a[2],&$a[3],&$a[4]); break;
			case 5: $instances[$className] = new $className(&$a[1],&$a[2],&$a[3],&$a[4],&$a[5]); break;
			case 6: $instances[$className] = new $className(&$a[1],&$a[2],&$a[3],&$a[4],&$a[5],&$a[6]); break;
			default: trigger_error('KjwSingleton: too many arguments for getInstance.', E_USER_ERROR);
			}
		}
		return $instances[$className];
	}
}

?>