<?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;
use Joomla\Registry\Registry;
use Joomla\String\StringHelper;
JLoader::register('FinderIndexerParser', __DIR__ . '/parser.php');
JLoader::register('FinderIndexerStemmer', __DIR__ . '/stemmer.php');
JLoader::register('FinderIndexerToken', __DIR__ . '/token.php');
/**
* Helper class for the Finder indexer package.
*
* @since 2.5
*/
class FinderIndexerHelper
{
/**
* The token stemmer object. The stemmer is set by whatever class
* wishes to use it but it must be an instance of FinderIndexerStemmer.
*
* @var FinderIndexerStemmer
* @since 2.5
*/
public static $stemmer;
/**
* A state flag, in order to not constantly check if the stemmer is an instance of FinderIndexerStemmer
*
* @var boolean
* @since 3.7.0
*/
protected static $stemmerOK;
/**
* Method to parse input into plain text.
*
* @param string $input The raw input.
* @param string $format The format of the input. [optional]
*
* @return string The parsed input.
*
* @since 2.5
* @throws Exception on invalid parser.
*/
public static function parse($input, $format = 'html')
{
// Get a parser for the specified format and parse the input.
return FinderIndexerParser::getInstance($format)->parse($input);
}
/**
* Method to tokenize a text string.
*
* @param string $input The input to tokenize.
* @param string $lang The language of the input.
* @param boolean $phrase Flag to indicate whether input could be a phrase. [optional]
*
* @return array|FinderIndexerToken An array of FinderIndexerToken objects or a single FinderIndexerToken object.
*
* @since 2.5
*/
public static function tokenize($input, $lang, $phrase = false)
{
static $cache;
$store = StringHelper::strlen($input) < 128 ? md5($input . '::' . $lang . '::' . $phrase) : null;
// Check if the string has been tokenized already.
if ($store && isset($cache[$store]))
{
return $cache[$store];
}
$tokens = array();
$quotes = html_entity_decode('‘’'', ENT_QUOTES, 'UTF-8');
// Get the simple language key.
$lang = static::getPrimaryLanguage($lang);
/*
* Parsing the string input into terms is a multi-step process.
*
* Regexes:
* 1. Remove everything except letters, numbers, quotes, apostrophe, plus, dash, period, and comma.
* 2. Remove plus, dash, period, and comma characters located before letter characters.
* 3. Remove plus, dash, period, and comma characters located after other characters.
* 4. Remove plus, period, and comma characters enclosed in alphabetical characters. Ungreedy.
* 5. Remove orphaned apostrophe, plus, dash, period, and comma characters.
* 6. Remove orphaned quote characters.
* 7. Replace the assorted single quotation marks with the ASCII standard single quotation.
* 8. Remove multiple space characters and replaces with a single space.
*/
$input = StringHelper::strtolower($input);
$input = preg_replace('#[^\pL\pM\pN\p{Pi}\p{Pf}\'+-.,]+#mui', ' ', $input);
$input = preg_replace('#(^|\s)[+-.,]+([\pL\pM]+)#mui', ' $1', $input);
$input = preg_replace('#([\pL\pM\pN]+)[+-.,]+(\s|$)#mui', '$1 ', $input);
$input = preg_replace('#([\pL\pM]+)[+.,]+([\pL\pM]+)#muiU', '$1 $2', $input);
$input = preg_replace('#(^|\s)[\'+-.,]+(\s|$)#mui', ' ', $input);
$input = preg_replace('#(^|\s)[\p{Pi}\p{Pf}]+(\s|$)#mui', ' ', $input);
$input = preg_replace('#[' . $quotes . ']+#mui', '\'', $input);
$input = preg_replace('#\s+#mui', ' ', $input);
$input = trim($input);
// Explode the normalized string to get the terms.
$terms = explode(' ', $input);
/*
* If we have Unicode support and are dealing with Chinese text, Chinese
* has to be handled specially because there are not necessarily any spaces
* between the "words". So, we have to test if the words belong to the Chinese
* character set and if so, explode them into single glyphs or "words".
*/
if ($lang === 'zh')
{
// Iterate through the terms and test if they contain Chinese.
for ($i = 0, $n = count($terms); $i < $n; $i++)
{
$charMatches = array();
$charCount = preg_match_all('#[\p{Han}]#mui', $terms[$i], $charMatches);
// Split apart any groups of Chinese characters.
for ($j = 0; $j < $charCount; $j++)
{
$tSplit = StringHelper::str_ireplace($charMatches[0][$j], '', $terms[$i], false);
if ((bool) $tSplit)
{
$terms[$i] = $tSplit;
}
else
{
unset($terms[$i]);
}
$terms[] = $charMatches[0][$j];
}
}
// Reset array keys.
$terms = array_values($terms);
}
/*
* If we have to handle the input as a phrase, that means we don't
* tokenize the individual terms and we do not create the two and three
* term combinations. The phrase must contain more than one word!
*/
if ($phrase === true && count($terms) > 1)
{
// Create tokens from the phrase.
$tokens[] = new FinderIndexerToken($terms, $lang);
}
else
{
// Create tokens from the terms.
for ($i = 0, $n = count($terms); $i < $n; $i++)
{
$tokens[] = new FinderIndexerToken($terms[$i], $lang);
}
// Create two and three word phrase tokens from the individual words.
for ($i = 0, $n = count($tokens); $i < $n; $i++)
{
// Setup the phrase positions.
$i2 = $i + 1;
$i3 = $i + 2;
// Create the two word phrase.
if ($i2 < $n && isset($tokens[$i2]))
{
// Tokenize the two word phrase.
$token = new FinderIndexerToken(
array(
$tokens[$i]->term,
$tokens[$i2]->term
), $lang, $lang === 'zh' ? '' : ' '
);
$token->derived = true;
// Add the token to the stack.
$tokens[] = $token;
}
// Create the three word phrase.
if ($i3 < $n && isset($tokens[$i3]))
{
// Tokenize the three word phrase.
$token = new FinderIndexerToken(
array(
$tokens[$i]->term,
$tokens[$i2]->term,
$tokens[$i3]->term
), $lang, $lang === 'zh' ? '' : ' '
);
$token->derived = true;
// Add the token to the stack.
$tokens[] = $token;
}
}
}
if ($store)
{
$cache[$store] = count($tokens) > 1 ? $tokens : array_shift($tokens);
return $cache[$store];
}
else
{
return count($tokens) > 1 ? $tokens : array_shift($tokens);
}
}
/**
* Method to get the base word of a token. This method uses the public
* {@link FinderIndexerHelper::$stemmer} object if it is set. If no stemmer is set,
* the original token is returned.
*
* @param string $token The token to stem.
* @param string $lang The language of the token.
*
* @return string The root token.
*
* @since 2.5
*/
public static function stem($token, $lang)
{
// Trim apostrophes at either end of the token.
$token = trim($token, '\'');
// Trim everything after any apostrophe in the token.
if ($res = explode('\'', $token))
{
$token = $res[0];
}
if (static::$stemmerOK === true)
{
return static::$stemmer->stem($token, $lang);
}
else
{
// Stem the token if we have a valid stemmer to use.
if (static::$stemmer instanceof FinderIndexerStemmer)
{
static::$stemmerOK = true;
return static::$stemmer->stem($token, $lang);
}
}
return $token;
}
/**
* Method to add a content type to the database.
*
* @param string $title The type of content. For example: PDF
* @param string $mime The mime type of the content. For example: PDF [optional]
*
* @return integer The id of the content type.
*
* @since 2.5
* @throws Exception on database error.
*/
public static function addContentType($title, $mime = null)
{
static $types;
$db = JFactory::getDbo();
$query = $db->getQuery(true);
// Check if the types are loaded.
if (empty($types))
{
// Build the query to get the types.
$query->select('*')
->from($db->quoteName('#__finder_types'));
// Get the types.
$db->setQuery($query);
$types = $db->loadObjectList('title');
}
// Check if the type already exists.
if (isset($types[$title]))
{
return (int) $types[$title]->id;
}
// Add the type.
$query->clear()
->insert($db->quoteName('#__finder_types'))
->columns(array($db->quoteName('title'), $db->quoteName('mime')))
->values($db->quote($title) . ', ' . $db->quote($mime));
$db->setQuery($query);
$db->execute();
// Return the new id.
return (int) $db->insertid();
}
/**
* Method to check if a token is common in a language.
*
* @param string $token The token to test.
* @param string $lang The language to reference.
*
* @return boolean True if common, false otherwise.
*
* @since 2.5
*/
public static function isCommon($token, $lang)
{
static $data;
static $default;
$langCode = $lang;
// If language requested is wildcard, use the default language.
if ($default === null && $lang === '*')
{
$default = strstr(self::getDefaultLanguage(), '-', true);
$langCode = $default;
}
// Load the common tokens for the language if necessary.
if (!isset($data[$langCode]))
{
$data[$langCode] = self::getCommonWords($langCode);
}
// Check if the token is in the common array.
return in_array($token, $data[$langCode], true);
}
/**
* Method to get an array of common terms for a language.
*
* @param string $lang The language to use.
*
* @return array Array of common terms.
*
* @since 2.5
* @throws Exception on database error.
*/
public static function getCommonWords($lang)
{
$db = JFactory::getDbo();
// Create the query to load all the common terms for the language.
$query = $db->getQuery(true)
->select($db->quoteName('term'))
->from($db->quoteName('#__finder_terms_common'))
->where($db->quoteName('language') . ' = ' . $db->quote($lang));
// Load all of the common terms for the language.
$db->setQuery($query);
return $db->loadColumn();
}
/**
* Method to get the default language for the site.
*
* @return string The default language string.
*
* @since 2.5
*/
public static function getDefaultLanguage()
{
static $lang;
// We need to go to com_languages to get the site default language, it's the best we can guess.
if (empty($lang))
{
$lang = JComponentHelper::getParams('com_languages')->get('site', 'en-GB');
}
return $lang;
}
/**
* Method to parse a language/locale key and return a simple language string.
*
* @param string $lang The language/locale key. For example: en-GB
*
* @return string The simple language string. For example: en
*
* @since 2.5
*/
public static function getPrimaryLanguage($lang)
{
static $data;
// Only parse the identifier if necessary.
if (!isset($data[$lang]))
{
if (is_callable(array('Locale', 'getPrimaryLanguage')))
{
// Get the language key using the Locale package.
$data[$lang] = Locale::getPrimaryLanguage($lang);
}
else
{
// Get the language key using string position.
$data[$lang] = StringHelper::substr($lang, 0, StringHelper::strpos($lang, '-'));
}
}
return $data[$lang];
}
/**
* Method to get the path (SEF route) for a content item.
*
* @param string $url The non-SEF route to the content item.
*
* @return string The path for the content item.
*
* @since 2.5
* @deprecated 4.0
*/
public static function getContentPath($url)
{
static $router;
// Only get the router once.
if (!($router instanceof JRouter))
{
// Get and configure the site router.
$config = JFactory::getConfig();
$router = JRouter::getInstance('site');
$router->setMode($config->get('sef', 1));
}
// Build the relative route.
$uri = $router->build($url);
$route = $uri->toString(array('path', 'query', 'fragment'));
$route = str_replace(JUri::base(true) . '/', '', $route);
return $route;
}
/**
* Method to get extra data for a content before being indexed. This is how
* we add Comments, Tags, Labels, etc. that should be available to Finder.
*
* @param FinderIndexerResult $item The item to index as a FinderIndexerResult object.
*
* @return boolean True on success, false on failure.
*
* @since 2.5
* @throws Exception on database error.
*/
public static function getContentExtras(FinderIndexerResult $item)
{
// Get the event dispatcher.
$dispatcher = JEventDispatcher::getInstance();
// Load the finder plugin group.
JPluginHelper::importPlugin('finder');
// Trigger the event.
$results = $dispatcher->trigger('onPrepareFinderContent', array(&$item));
// Check the returned results. This is for plugins that don't throw
// exceptions when they encounter serious errors.
if (in_array(false, $results))
{
throw new Exception($dispatcher->getError(), 500);
}
return true;
}
/**
* Method to process content text using the onContentPrepare event trigger.
*
* @param string $text The content to process.
* @param Registry $params The parameters object. [optional]
* @param FinderIndexerResult $item The item which get prepared. [optional]
*
* @return string The processed content.
*
* @since 2.5
*/
public static function prepareContent($text, $params = null, FinderIndexerResult $item = null)
{
static $loaded;
// Get the dispatcher.
$dispatcher = JEventDispatcher::getInstance();
// Load the content plugins if necessary.
if (empty($loaded))
{
JPluginHelper::importPlugin('content');
$loaded = true;
}
// Instantiate the parameter object if necessary.
if (!($params instanceof Registry))
{
$registry = new Registry($params);
$params = $registry;
}
// Create a mock content object.
$content = JTable::getInstance('Content');
$content->text = $text;
if ($item)
{
$content->bind((array) $item);
$content->bind($item->getElements());
}
if ($item && !empty($item->context))
{
$content->context = $item->context;
}
// Fire the onContentPrepare event.
$dispatcher->trigger('onContentPrepare', array('com_finder.indexer', &$content, &$params, 0));
return $content->text;
}
}