WordPress Version: 6.3
/**
* Returns contents of an inline script used in appending polyfill scripts for
* browsers which fail the provided tests. The provided array is a mapping from
* a condition to verify feature support to its polyfill script handle.
*
* @since 5.0.0
*
* @param WP_Scripts $scripts WP_Scripts object.
* @param string[] $tests Features to detect.
* @return string Conditional polyfill inline script.
*/
function wp_get_script_polyfill($scripts, $tests)
{
$polyfill = '';
foreach ($tests as $test => $handle) {
if (!array_key_exists($handle, $scripts->registered)) {
continue;
}
$src = $scripts->registered[$handle]->src;
$ver = $scripts->registered[$handle]->ver;
if (!preg_match('|^(https?:)?//|', $src) && !($scripts->content_url && str_starts_with($src, $scripts->content_url))) {
$src = $scripts->base_url . $src;
}
if (!empty($ver)) {
$src = add_query_arg('ver', $ver, $src);
}
/** This filter is documented in wp-includes/class-wp-scripts.php */
$src = esc_url(apply_filters('script_loader_src', $src, $handle));
if (!$src) {
continue;
}
$polyfill .= '( ' . $test . ' ) || ' . 'document.write( \'<script src="' . $src . '"></scr\' + \'ipt>\' );';
}
return $polyfill;
}