<?php
//
// +--------------------------------------------------------------------+
// | Sourdough PHP Application Framework                                |
// +--------------------------------------------------------------------+
// | Copyright (c) 2001-2007 Philip Iezzi, phpee.com                    |
// | Web           http://sourdough.phpee.com/                          |
// | License       GNU Lesser General Public License (LGPL)             |
// +--------------------------------------------------------------------+
// | This library is free software; you can redistribute it and/or      |
// | modify it under the terms of the GNU Lesser General Public         |
// | License as published by the Free Software Foundation; either       |
// | version 2.1 of the License, or (at your option) any later version. |
// +--------------------------------------------------------------------+
//

/**
* Sourdough PHP Application Framework
* @package      sourdough
* @subpackage   xslt
*/
/**
* SOURDOUGH XSLT object factory
*
* Static factory class to produce XSLT transformation objects.
* Detects the available libraries automatically and includes the needed class files.
*
* @static
* @package      sourdough
* @subpackage   xslt
* @author       Philip Iezzi <pipo at phpee dot com>
* @copyright    Copyright (c) 2001-2007 PHPEE.COM
* @license      http://opensource.org/licenses/lgpl-license.php GNU Lesser General Public License
* @version      $Id: Sd_XsltFactory.class.php 3003 2007-12-08 11:05:17Z piezzi $
*/
class Sd_XsltFactory {
//[start] Constants
	/** 
	 * Sablotron XSLT processor
	 */
	const ENGINE_SABLOT = 'sablot';
	/** 
	 * DOMXML XSLT processor
	 */
	const ENGINE_DOM = 'dom';
	/**
	 * XSLTPROC XSLT processor
	 */
	const ENGINE_XSLTPROC = 'xsltproc';
	/**
	 * Xalan XSLT processor
	 */
	const ENGINE_XALAN = 'xalan';
	/**
	 * PHP5 built-in XSLT processor
	 */
	const ENGINE_PHP5 = 'php5';
//[end]

//[start] Local Variables
	/**
	* XSLT configuration
	*
	* @var		array
	*/
	private static $conf = array();
//[end]

//[start] Constructor
	/**
	* Protect constructor since it is a static only class.
	*/
	protected function __construct() {}
//[end]

//[start] Public Methods
	/**
	* Create a new Xslt object
	*
	* @param    Sourdough    $Sourd       Sourdough framework core object
	* @return   Sd_Xslt                   Newly created Xslt object
	*/
	public static function getXslt(Sourdough $Sourd)
	{
		self::$conf = $Sourd->getConf('xslt');
		
		if (self::$conf['force_engine']) {
			if(!self::engine_available(self::$conf['engine']))
				Sd_ErrorManager::raiseError(0, "Could not load XSLT engine (" . self::$conf['engine'] . ").");
			$engine = self::$conf['engine'];
		} else {
			if (self::engine_available(self::ENGINE_PHP5)) {
				$engine = self::ENGINE_PHP5;
			} else if (self::engine_available(self::ENGINE_XSLTPROC)) {
				$engine = self::ENGINE_XSLTPROC;
			} else if (self::engine_available(self::ENGINE_DOM)) {
				$engine = self::ENGINE_DOM;
			} else if (self::engine_available(self::ENGINE_SABLOT)) {
				$engine = self::ENGINE_SABLOT;
			} else if (self::engine_available(self::ENGINE_XALAN)) {
				$engine = self::ENGINE_XALAN;
			} else {
				Sd_ErrorManager::raiseError(0, "Could not load any XSLT engine.");
			}
		}
		
		$phpext = $Sourd->getConf('php_ext');
		$path = dirname(__FILE__).'/';
		include_once($path.'Sd_Xslt.class.'.$phpext);
		include_once($path.'Sd_Xslt_'.$engine.'.class.'.$phpext);
		$class = 'Sd_Xslt_'.$engine;
		return new $class($Sourd);
	}
//[end]

//[start] Protected/Private Methods
	/**
	* Check if an engine is available
	*
	* @param    string     $engine        XSLT engine
	* @return   boolean                   true if engine is available
	*/
	private static function engine_available($engine)
	{
		switch($engine) {
			case self::ENGINE_PHP5:
				return class_exists('xsltprocessor');
			case self::ENGINE_XSLTPROC:
				return @file_exists(self::$conf['xsltproc_bin']);
			case self::ENGINE_DOM:
				return function_exists('domxml_xslt_stylesheet');
			case self::ENGINE_SABLOT:
				return function_exists('xslt_create');
			case self::ENGINE_XALAN:
				return @file_exists(self::$conf['xalan_bin']);
			default:
				return false;
		}
	}
//[end]
}
?>