dynamic_sidebar( int|string $index = 1 ): bool

Display dynamic sidebar.

Description

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.

Parameters

$indexint|stringoptional
Index, name or ID of dynamic sidebar.

Default:1

Return

bool True, if widget sidebar was found and called. False if not found or not called.

Source

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 );
}

Hooks

do_action( ‘dynamic_sidebar’, array $widget )

Fires before a widget’s display callback is called.

do_action( ‘dynamic_sidebar_after’, int|string $index, bool $has_widgets )

Fires after widgets are rendered in a dynamic sidebar.

do_action( ‘dynamic_sidebar_before’, int|string $index, bool $has_widgets )

Fires before widgets are rendered in a dynamic sidebar.

apply_filters( ‘dynamic_sidebar_has_widgets’, bool $did_one, int|string $index )

Filters whether a sidebar has widgets.

apply_filters( ‘dynamic_sidebar_params’, array $params )

Filters the parameters passed to a widget’s display callback.

Changelog

VersionDescription
2.2.0Introduced.

User Contributed Notes

  1. Skip to note 4 content

    Here is the recommended use of this function:

    <?php if ( is_active_sidebar( 'left-sidebar' ) ) : ?>
    	<ul id="sidebar">
    		<?php dynamic_sidebar( 'left-sidebar' ); ?>
    	</ul>
    <?php endif; ?>
    <ul id="sidebar">
    	<?php dynamic_sidebar( 'right-sidebar' ); ?>
    </ul>
    <ul id="sidebar">
    <?php if ( ! dynamic_sidebar() ) : ?>
    	<li>{static sidebar item 1}</li>
    	<li>{static sidebar item 2}</li>
    <?php endif; ?>
    </ul>
  2. Skip to note 5 content

    dynamic_sidebar() callback is useful for, if you have no sidebar.php file to query and; for using sidebars that may not have a template. Hence the term “dynamic.” By dynamic this means the sidebar may have been generated in the themes register_sidebar(array($arguments)) function.

    As @Codex demonstrates, it is always good to verify the sidebar is ACTIVE (set in the Widgets admin page) and not empty. This prevents an empty div section on the page which might create empty space or broken alignment of page view. Using PHP conditional statements like else, if or case switch; in your template is the safest way to render a dynamic sidebar. It also give your theme context if the admin has not found the time to put a sidebar into a widget.

    <section id="sidebar">
    
        <?php if ( is_active_sidebar( 'sidebar' ) ) : ?>
        
        <?php dynamic_sidebar('sidebar'); ?><br>
        
            <?php else : ?>
        
            <div class="meta-default">
    
                <?php /* optional */ 
    			the_widget( 'WP_Widget_Categories', '', '' ); ?>
                    <?php /* minimal */ 
    				get_search_form(); ?>
    
    					<nav class="sidebar-login">
                            <ul><?php wp_loginout(); ?></ul>
    					</nav>
            </div>
    
        <?php endif;  ?>
    
    </section>
  3. Skip to note 6 content

    I just got into hell with the famous

    Your theme has 3 widget areas, but this particular page doesn’t display them.

    You can navigate to other pages on your site while using the Customiser to view and edit the widgets displayed on those pages.

    Turns out activating jquery from a CDN for me leads to that error.

    Not sure at that point if it is a specific version error or CDN. THus, I heard WordPress has jQuery integrated now

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