<?php /** * @package Joomla.Administrator * @subpackage com_finder * * @copyright Copyright (C) 2005 - 2019 Open Source Matters, Inc. All rights reserved. * @license GNU General Public License version 2 or later; see LICENSE.txt */ defined('_JEXEC') or die; /** * Stemmer base class for the Finder indexer package. * * @since 2.5 */ abstract class FinderIndexerStemmer { /** * An internal cache of stemmed tokens. * * @var array * @since 2.5 */ public $cache = array(); /** * Method to get a stemmer, creating it if necessary. * * @param string $adapter The type of stemmer to load. * * @return FinderIndexerStemmer A FinderIndexerStemmer instance. * * @since 2.5 * @throws Exception on invalid stemmer. */ public static function getInstance($adapter) { static $instances; // Only create one stemmer for each adapter. if (isset($instances[$adapter])) { return $instances[$adapter]; } // Create an array of instances if necessary. if (!is_array($instances)) { $instances = array(); } // Setup the adapter for the stemmer. $adapter = JFilterInput::getInstance()->clean($adapter, 'cmd'); $path = __DIR__ . '/stemmer/' . $adapter . '.php'; $class = 'FinderIndexerStemmer' . ucfirst($adapter); // Check if a stemmer exists for the adapter. if (!file_exists($path)) { // Throw invalid adapter exception. throw new Exception(JText::sprintf('COM_FINDER_INDEXER_INVALID_STEMMER', $adapter)); } // Instantiate the stemmer. JLoader::register($class, $path); $instances[$adapter] = new $class; return $instances[$adapter]; } /** * Method to stem a token and return the root. * * @param string $token The token to stem. * @param string $lang The language of the token. * * @return string The root token. * * @since 2.5 */ abstract public function stem($token, $lang); }