Ticket #9959: wp_rel_nofollow.txt

<?php

/* eliminates the need for function wp_rel_nofollow_callback */
function wp_rel_nofollow( $text ) {
        global $wpdb;
        // This is a pre save filter, so text is already escaped.
        $text = stripslashes($text);
        $r = array(
                "|(<a\b[^>]*?\srel=['\"])(?![^'\"]*\bnofollow\b)|i" => "$1nofollow ",
                "|<a\b(?![^>]*\srel=['\"])|i" => '<a rel="nofollow"'
        );
        $text = preg_replace(array_keys($r), array_values($r), $text);
        $text = $wpdb->escape($text);
        return $text;
}

/* replace these */
/**
 * Adds rel nofollow string to all HTML A elements in content.
 *
 * @since 1.5.0
 *
 * @param string $text Content that may contain HTML A elements.
 * @return string Converted content.
 */
function wp_rel_nofollow( $text ) {
        global $wpdb;
        // This is a pre save filter, so text is already escaped.
        $text = stripslashes($text);
        $text = preg_replace_callback('|<a (.+?)>|i', 'wp_rel_nofollow_callback', $text);
        $text = $wpdb->escape($text);
        return $text;
}

/**
 * Callback to used to add rel=nofollow string to HTML A element.
 *
 * Will remove already existing rel="nofollow" and rel='nofollow' from the
 * string to prevent from invalidating (X)HTML.
 *
 * @since 2.3.0
 *
 * @param array $matches Single Match
 * @return string HTML A Element with rel nofollow.
 */
function wp_rel_nofollow_callback( $matches ) {
        $text = $matches[1];
        $text = str_replace(array(' rel="nofollow"', " rel='nofollow'"), '', $text);
        return "<a $text rel=\"nofollow\">";
}

?>