By default this displays the default sidebar or 'sidebar-1'. If your theme specifies the 'id' or 'name' parameter for its registered sidebars you can pass an ID or name as the $index parameter. Otherwise, you can pass in a numerical index to display the sidebar at that index.
This example shows how to output the first non-empty sidebar (no sidebar id was specified when registering) or if it is not found, then display the specified code:
Here we check if the bar and its widgets were present. We'll check for a panel so that we don't have to display extra HTML tags (<ul id="sidebar">) if the sidebar is empty:
When registering more than one widget bar with register_sidebar(), it is more convenient to specify an id for each bar.
We can NOT specify an id, then the panel will get a serial number. But in this case, when editing the theme will be difficult to understand which panel is which, because the numbers 1, 2, 3 does not say anything. But if we specify a name, it becomes much clearer:
From the example, you can see that strings are more convenient: when you look in a theme and see dynamic_sidebar('top_menu' ) it is immediately clear that the main menu bar is called.
The id argument MUST NOT contain spaces, capital letters, or non Latin letters. It can use a dash - and underscore _. It must also be unique. By specifying the id we can also specify the name, description and translations for them:
register_sidebar( [
'id' => 'top-menu',
'name' => __( 'Top Menu', $text_domain ),
'description' => __( 'This sidebar is located above the age logo.', $text_domain ),
] );
Notes
Global. Array. $wp_registered_sidebars The registered sidebars.
Global. Array. $wp_registered_widgets The registered widgets.
function dynamic_sidebar( $index = 1 ) {
global $wp_registered_sidebars, $wp_registered_widgets;
if ( is_int( $index ) ) {
$index = "sidebar-$index";
} else {
$index = sanitize_title( $index );
foreach ( (array) $wp_registered_sidebars as $key => $value ) {
if ( sanitize_title( $value['name'] ) === $index ) {
$index = $key;
break;
}
}
}
$sidebars_widgets = wp_get_sidebars_widgets();
if ( empty( $wp_registered_sidebars[ $index ] ) || empty( $sidebars_widgets[ $index ] ) || ! is_array( $sidebars_widgets[ $index ] ) ) {
/** This action is documented in wp-includes/widget.php */
do_action( 'dynamic_sidebar_before', $index, false );
/** This action is documented in wp-includes/widget.php */
do_action( 'dynamic_sidebar_after', $index, false );
/** This filter is documented in wp-includes/widget.php */
return apply_filters( 'dynamic_sidebar_has_widgets', false, $index );
}
$sidebar = $wp_registered_sidebars[ $index ];
$sidebar['before_sidebar'] = sprintf( $sidebar['before_sidebar'], $sidebar['id'], $sidebar['class'] );
/**
* Fires before widgets are rendered in a dynamic sidebar.
*
* Note: The action also fires for empty sidebars, and on both the front end
* and back end, including the Inactive Widgets sidebar on the Widgets screen.
*
* @since 3.9.0
*
* @param int|string $index Index, name, or ID of the dynamic sidebar.
* @param bool $has_widgets Whether the sidebar is populated with widgets.
* Default true.
*/
do_action( 'dynamic_sidebar_before', $index, true );
if ( ! is_admin() && ! empty( $sidebar['before_sidebar'] ) ) {
echo $sidebar['before_sidebar'];
}
$did_one = false;
foreach ( (array) $sidebars_widgets[ $index ] as $id ) {
if ( ! isset( $wp_registered_widgets[ $id ] ) ) {
continue;
}
$params = array_merge(
array(
array_merge(
$sidebar,
array(
'widget_id' => $id,
'widget_name' => $wp_registered_widgets[ $id ]['name'],
)
),
),
(array) $wp_registered_widgets[ $id ]['params']
);
// Substitute HTML `id` and `class` attributes into `before_widget`.
$classname_ = '';
foreach ( (array) $wp_registered_widgets[ $id ]['classname'] as $cn ) {
if ( is_string( $cn ) ) {
$classname_ .= '_' . $cn;
} elseif ( is_object( $cn ) ) {
$classname_ .= '_' . get_class( $cn );
}
}
$classname_ = ltrim( $classname_, '_' );
$params[0]['before_widget'] = sprintf(
$params[0]['before_widget'],
str_replace( '\\', '_', $id ),
$classname_
);
/**
* Filters the parameters passed to a widget's display callback.
*
* Note: The filter is evaluated on both the front end and back end,
* including for the Inactive Widgets sidebar on the Widgets screen.
*
* @since 2.5.0
*
* @see register_sidebar()
*
* @param array $params {
* @type array $args {
* An array of widget display arguments.
*
* @type string $name Name of the sidebar the widget is assigned to.
* @type string $id ID of the sidebar the widget is assigned to.
* @type string $description The sidebar description.
* @type string $class CSS class applied to the sidebar container.
* @type string $before_widget HTML markup to prepend to each widget in the sidebar.
* @type string $after_widget HTML markup to append to each widget in the sidebar.
* @type string $before_title HTML markup to prepend to the widget title when displayed.
* @type string $after_title HTML markup to append to the widget title when displayed.
* @type string $widget_id ID of the widget.
* @type string $widget_name Name of the widget.
* }
* @type array $widget_args {
* An array of multi-widget arguments.
*
* @type int $number Number increment used for multiples of the same widget.
* }
* }
*/
$params = apply_filters( 'dynamic_sidebar_params', $params );
$callback = $wp_registered_widgets[ $id ]['callback'];
/**
* Fires before a widget's display callback is called.
*
* Note: The action fires on both the front end and back end, including
* for widgets in the Inactive Widgets sidebar on the Widgets screen.
*
* The action is not fired for empty sidebars.
*
* @since 3.0.0
*
* @param array $widget {
* An associative array of widget arguments.
*
* @type string $name Name of the widget.
* @type string $id Widget ID.
* @type callable $callback When the hook is fired on the front end, `$callback` is an array
* containing the widget object. Fired on the back end, `$callback`
* is 'wp_widget_control', see `$_callback`.
* @type array $params An associative array of multi-widget arguments.
* @type string $classname CSS class applied to the widget container.
* @type string $description The widget description.
* @type array $_callback When the hook is fired on the back end, `$_callback` is populated
* with an array containing the widget object, see `$callback`.
* }
*/
do_action( 'dynamic_sidebar', $wp_registered_widgets[ $id ] );
if ( is_callable( $callback ) ) {
call_user_func_array( $callback, $params );
$did_one = true;
}
}
if ( ! is_admin() && ! empty( $sidebar['after_sidebar'] ) ) {
echo $sidebar['after_sidebar'];
}
/**
* Fires after widgets are rendered in a dynamic sidebar.
*
* Note: The action also fires for empty sidebars, and on both the front end
* and back end, including the Inactive Widgets sidebar on the Widgets screen.
*
* @since 3.9.0
*
* @param int|string $index Index, name, or ID of the dynamic sidebar.
* @param bool $has_widgets Whether the sidebar is populated with widgets.
* Default true.
*/
do_action( 'dynamic_sidebar_after', $index, true );
/**
* Filters whether a sidebar has widgets.
*
* Note: The filter is also evaluated for empty sidebars, and on both the front end
* and back end, including the Inactive Widgets sidebar on the Widgets screen.
*
* @since 3.9.0
*
* @param bool $did_one Whether at least one widget was rendered in the sidebar.
* Default false.
* @param int|string $index Index, name, or ID of the dynamic sidebar.
*/
return apply_filters( 'dynamic_sidebar_has_widgets', $did_one, $index );
}