Checks that a JSONP callback is a valid JavaScript callback name.

Only allows alphanumeric characters and the dot character in callback function names. This helps to mitigate XSS attacks caused by directly outputting user input.

$callback string Required

Supplied JSONP callback function name.

bool Whether the callback function name is valid.

File: wp-includes/functions.php. View all references

function wp_check_jsonp_callback( $callback ) {
	if ( ! is_string( $callback ) ) {
		return false;
	}

	preg_replace( '/[^\w\.]/', '', $callback, -1, $illegal_char_count );

	return 0 === $illegal_char_count;
}