/**
* Split a string into a clean array of keywords
* @param $text string
* @param $allowWildcards boolean
* @return array of keywords
*/
function &filterKeywords($text, $allowWildcards = false)
{
$minLength = Config::getVar('search', 'min_word_length');
$maxLength = Config::getVar('search', 'max_word_length');
$stopwords =& SearchIndex::loadStopwords();
// Remove punctuation
if (is_array($text)) {
$text = join("\n", $text);
}
$cleanText = String::regexp_replace('/[!"\\#\\$%\'\\(\\)\\.\\?@\\[\\]\\^`\\{\\}~]/', '', $text);
$cleanText = String::regexp_replace('/[\\+,:;&\\/<=>\\|\\\\]/', ' ', $cleanText);
$cleanText = String::regexp_replace('/[\\*]/', $allowWildcards ? '%' : ' ', $cleanText);
$cleanText = String::strtolower($cleanText);
// Split into words
$words = String::regexp_split('/\\s+/', $cleanText);
// FIXME Do not perform further filtering for some fields, e.g., author names?
// Remove stopwords
$keywords = array();
foreach ($words as $k) {
if (!isset($stopwords[$k]) && String::strlen($k) >= $minLength && !is_numeric($k)) {
$keywords[] = String::substr($k, 0, $maxLength);
}
}
return $keywords;
}
