WordPress at a glance
function is not described

wp_kses_attr() WP 1.0.0

Removes all attributes, if none are allowed for this element.

If some are allowed it calls wp_kses_hair() to split them further, and then it builds up new HTML code from the data that kses_hair() returns. It also removes "<" and ">" characters, if there are any left. One more thing it does is to check if the tag has a closing XHTML slash, and if it does, it puts one in the returned code as well.

No Hooks.


String. Sanitized HTML element


wp_kses_attr( $element, $attr, $allowed_html, $allowed_protocols );
$element(string) (required)
HTML element/tag
$attr(string) (required)
HTML attributes from HTML element to closing HTML element tag
$allowed_html(array) (required)
Allowed HTML elements
$allowed_protocols(array) (required)
Allowed protocols to keep

Code of wp kses attr: wp-includes/kses.php VER 5.0.3

function wp_kses_attr($element, $attr, $allowed_html, $allowed_protocols) {
	if ( ! is_array( $allowed_html ) )
		$allowed_html = wp_kses_allowed_html( $allowed_html );

	// Is there a closing XHTML slash at the end of the attributes?
	$xhtml_slash = '';
	if (preg_match('%\s*/\s*$%', $attr))
		$xhtml_slash = ' /';

	// Are any attributes allowed at all for this element?
	$element_low = strtolower( $element );
	if ( empty( $allowed_html[ $element_low ] ) || true === $allowed_html[ $element_low ] ) {
		return "<$element$xhtml_slash>";

	// Split it
	$attrarr = wp_kses_hair($attr, $allowed_protocols);

	// Go through $attrarr, and save the allowed attributes for this element
	// in $attr2
	$attr2 = '';
	foreach ( $attrarr as $arreach ) {
		if ( wp_kses_attr_check( $arreach['name'], $arreach['value'], $arreach['whole'], $arreach['vless'], $element, $allowed_html ) ) {
			$attr2 .= ' '.$arreach['whole'];

	// Remove any "<" or ">" characters
	$attr2 = preg_replace('/[<>]/', '', $attr2);

	return "<$element$attr2$xhtml_slash>";