sanitizeTags, version 1.0 (Daniel Mota aka IceBeat)

/*  sanitizeTags, version 1.0: http://icebeat.bitacoras.com
 *  (c) 2005 Daniel Mota aka IceBeat <[email protected]>
 *
/*--------------------------------------------------------------------------*/
function sanitizeTags($tags='',$mode=0) {
	$tags = strtolower($tags);
	$new_tags = array();
	$words = array();
	$_tags = preg_split('!(\+|-|\||\s)!',$tags,-1,PREG_SPLIT_DELIM_CAPTURE);
	if(count($_tags)>1) {
		$tag = current($_tags);
		if(strlen($tag)>=4) $new_tags[] = $tag;
		next($_tags);
		while ($del = current($_tags)) {
			next($_tags);
			$tag = current($_tags);
			if(strlen($tag)>=4) {
				switch ( $del ) {
					case '+': 	$new_tags[] = '+'.$tag; break;
					case '-': 	$new_tags[] = '-'.$tag; break;	
					default: 	$new_tags[] = $tag; 	break;
				}
				$words[] = $tag;
			}
			next($_tags);
		}
	} elseif(strlen($_tags[0])>=4) {
		$new_tags[] = $_tags[0];
		$words[] = $_tags[0];
	}
	$tags = join(chr(32),$new_tags);
	$query = preg_match('!(\+|-)!', $tags) ? "('+".$tags."' IN BOOLEAN MODE)": "('".$tags."')";
	$query = 'WHERE MATCH (tags) AGAINST '.$query;
	if($mode==1) return $words;
	if($mode==2) return array($words,$query);
	return $query;
}
 
//ejemplo
//$q = 'SELECT * from mitabla '.sanitizeTags('icebeat+web');