ParserRegistry.php

<?php
/**
 * Copyright 2010-2012, Cake Development Corporation (http://cakedc.com)
 *
 * Licensed under The MIT License
 * Redistributions of files must retain the above copyright notice.
 *
 * @copyright Copyright 2010-2012, Cake Development Corporation (http://cakedc.com)
 * @license MIT License (http://www.opensource.org/licenses/mit-license.php)
 */

/**
 * Parser Registry. A factory to return parser instances from available parsers listed using the Configure class
 *
 * To setup a new parser use
 *
 *		Configure::write('Parsers.my_parser' => array(
 *			'name' => 'MyParser',
 *			'className' => 'MyPlugin.MyParser'
 *		))
 *
 * @package markup_parsers
 * @subpackage markup_parsers.libs
 */
class ParserRegistry {

/**
 * Available parsers
 *
 * @var array
 */
	protected static $_parsers = null;

/**
 * Available parsers
 *
 * @var array
 */
	protected static $_availableParsers = array();

/**
 * Initializes the registry by loading all the existing parsers
 *
 * @return void
 */
	protected static function _init() {
		$defaults = array(
			'markdown' => array(
				'name' => 'Markdown',
				'className' => 'MarkupParsers.Markdown'),
			'bbcode' => array(
				'name' => 'BBCode',
				'className' => 'MarkupParsers.Bbcode'),
			'html' => array(
				'name' => 'Html',
				'className' => 'MarkupParsers.Html'),
			'textile' => array(
				'name' => 'Textile',
				'className' => 'MarkupParsers.Textile'
			)
		);

		if (empty(self::$_availableParsers)) {
			self::$_availableParsers = array_merge($defaults, (array)Configure::read('Parsers'));
		}
	}

/**
 * Returns the parsers that implements the passed interfaces
 *
 * @return array
 */
	public static function getParsers() {
		self::_init();

		$result = array();
		foreach (self::$_availableParsers as $key => $parser) {
			$result[$key] = $parser['name'];
		}

		return $result;
	}

/**
 * Returns a parser instance
 *
 * @param string parser key
 * @return object Parser instance
 *
 */
	public static function getParser($parser = '') {
		self::_init();

		if (empty(self::$_parsers[$parser])) {
			list($plugin, $class) = pluginSplit(self::$_availableParsers[$parser]['className']);
			$location = (!empty($plugin) ? $plugin . '.' : '' ) . 'Parser';
			$class .= 'Parser';
			App::uses($class, $location);

			if (!class_exists($class)) {
				throw new Exception(__d('markup_parsers', 'Invalid Parser', true));
			}
			self::$_parsers[$parser] = new $class();
		}

		return self::$_parsers[$parser];
	}

}