wp-includes/formatting.php:4725Escaping for XML blocks.
$textstringstringOne hook fires while esc_xml() runs, in this order:
Filters a string cleaned and escaped for output in XML.
function esc_xml( $text ) { $safe_text = wp_check_invalid_utf8( $text ); $cdata_regex = '\<\!\[CDATA\[.*?\]\]\>'; $regex = <<<EOF/ (?=.*?{$cdata_regex}) # lookahead that will match anything followed by a CDATA Section (?<non_cdata_followed_by_cdata>(.*?)) # the "anything" matched by the lookahead (?<cdata>({$cdata_regex})) # the CDATA Section matched by the lookahead | # alternative (?<non_cdata>(.*)) # non-CDATA Section/sxEOF; $safe_text = (string) preg_replace_callback( $regex, static function ( $matches ) { if ( ! isset( $matches[0] ) ) { return ''; } if ( isset( $matches['non_cdata'] ) ) { // escape HTML entities in the non-CDATA Section. return _wp_specialchars( $matches['non_cdata'], ENT_XML1 ); } // Return the CDATA Section unchanged, escape HTML entities in the rest. return _wp_specialchars( $matches['non_cdata_followed_by_cdata'], ENT_XML1 ) . $matches['cdata']; }, $safe_text ); /** * Filters a string cleaned and escaped for output in XML. * * Text passed to esc_xml() is stripped of invalid or special characters * before output. HTML named character references are converted to their * equivalent code points. * * @since 5.5.0 * * @param string $safe_text The text after it has been escaped. * @param string $text The text prior to being escaped. */ return apply_filters( 'esc_xml', $safe_text, $text );}Introduced in 5.5.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/formatting.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.