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wp_check_jsonp_callback() WP 4.6.0

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.

No Hooks.

Return

true|false. Whether the callback function name is valid.

Usage

wp_check_jsonp_callback( $callback );
$callback(string) (required)
Supplied JSONP callback function name.

Changelog

Since 4.6.0 Introduced.

Code of wp_check_jsonp_callback() WP 5.7

<?php
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;
}