Source
File: wp-admin/includes/widgets.php
function wp_list_widget_controls( $sidebar, $sidebar_name = '' ) {
add_filter( 'dynamic_sidebar_params', 'wp_list_widget_controls_dynamic_sidebar' );
$description = wp_sidebar_description( $sidebar );
echo '<div id="' . esc_attr( $sidebar ) . '" class="widgets-sortables">';
if ( $sidebar_name ) {
$add_to = sprintf(
/* translators: %s: Widgets sidebar name. */
__( 'Add to: %s' ),
$sidebar_name
);
?>
<div class="sidebar-name" data-add-to="<?php echo esc_attr( $add_to ); ?>">
<button type="button" class="handlediv hide-if-no-js" aria-expanded="true">
<span class="screen-reader-text"><?php echo esc_html( $sidebar_name ); ?></span>
<span class="toggle-indicator" aria-hidden="true"></span>
</button>
<h2><?php echo esc_html( $sidebar_name ); ?> <span class="spinner"></span></h2>
</div>
<?php
}
if ( ! empty( $description ) ) {
?>
<div class="sidebar-description">
<p class="description"><?php echo $description; ?></p>
</div>
<?php
}
dynamic_sidebar( $sidebar );
echo '</div>';
}