* This API is used for creating dynamic sidebar without hardcoding functionality into
* Includes both internal WordPress routines and theme-use routines.
* This functionality was found in a plugin before the WordPress 2.2 release, which
* included it in the core from that point on.
* @link https://wordpress.org/support/article/wordpress-widgets/
* @link https://developer.wordpress.org/themes/functionality/widgets/
global $wp_registered_sidebars, $wp_registered_widgets, $wp_registered_widget_controls, $wp_registered_widget_updates;
* Stores the sidebars, since many themes can have more than one.
* @global array $wp_registered_sidebars Registered sidebars.
$wp_registered_sidebars = array();
* Stores the registered widgets.
* @global array $wp_registered_widgets
$wp_registered_widgets = array();
* Stores the registered widget controls (options).
* @global array $wp_registered_widget_controls
$wp_registered_widget_controls = array();
* @global array $wp_registered_widget_updates
$wp_registered_widget_updates = array();
* @global array $_wp_sidebars_widgets
$_wp_sidebars_widgets = array();
* @global array $_wp_deprecated_widgets_callbacks
$GLOBALS['_wp_deprecated_widgets_callbacks'] = array(
'wp_widget_pages_control',
'wp_widget_calendar_control',
'wp_widget_archives_control',
'wp_widget_meta_control',
'wp_widget_recent_entries',
'wp_widget_recent_entries_control',
'wp_widget_tag_cloud_control',
'wp_widget_categories_control',
'wp_widget_text_control',
'wp_widget_recent_comments',
'wp_widget_recent_comments_control',
// Template tags & API functions.
* Registers a WP_Widget widget
* @since 4.6.0 Updated the `$widget` parameter to also accept a WP_Widget instance object
* instead of simply a `WP_Widget` subclass name.
* @global WP_Widget_Factory $wp_widget_factory
* @param string|WP_Widget $widget Either the name of a `WP_Widget` subclass or an instance of a `WP_Widget` subclass.
function register_widget( $widget ) {
global $wp_widget_factory;
$wp_widget_factory->register( $widget );
* Unregisters a WP_Widget widget. Useful for un-registering default widgets.
* Run within a function hooked to the {@see 'widgets_init'} action.
* @since 4.6.0 Updated the `$widget` parameter to also accept a WP_Widget instance object
* instead of simply a `WP_Widget` subclass name.
* @global WP_Widget_Factory $wp_widget_factory
* @param string|WP_Widget $widget Either the name of a `WP_Widget` subclass or an instance of a `WP_Widget` subclass.
function unregister_widget( $widget ) {
global $wp_widget_factory;
$wp_widget_factory->unregister( $widget );
* Creates multiple sidebars.
* If you wanted to quickly create multiple sidebars for a theme or internally.
* This function will allow you to do so. If you don't pass the 'name' and/or
* 'id' in `$args`, then they will be built for you.
* @see register_sidebar() The second parameter is documented by register_sidebar() and is the same here.
* @global array $wp_registered_sidebars The new sidebars are stored in this array by sidebar ID.
* @param int $number Optional. Number of sidebars to create. Default 1.
* @param array|string $args {
* Optional. Array or string of arguments for building a sidebar.
* @type string $id The base string of the unique identifier for each sidebar. If provided, and multiple
* sidebars are being defined, the ID will have "-2" appended, and so on.
* Default 'sidebar-' followed by the number the sidebar creation is currently at.
* @type string $name The name or title for the sidebars displayed in the admin dashboard. If registering
* more than one sidebar, include '%d' in the string as a placeholder for the uniquely
* assigned number for each sidebar.
* Default 'Sidebar' for the first sidebar, otherwise 'Sidebar %d'.
function register_sidebars( $number = 1, $args = array() ) {
global $wp_registered_sidebars;
if ( is_string( $args ) ) {
parse_str( $args, $args );
for ( $i = 1; $i <= $number; $i++ ) {
if ( isset( $args['name'] ) ) {
$_args['name'] = sprintf( $args['name'], $i );
/* translators: %d: Sidebar number. */
$_args['name'] = sprintf( __( 'Sidebar %d' ), $i );
$_args['name'] = isset( $args['name'] ) ? $args['name'] : __( 'Sidebar' );
// Custom specified ID's are suffixed if they exist already.
// Automatically generated sidebar names need to be suffixed regardless starting at -0.
if ( isset( $args['id'] ) ) {
$_args['id'] = $args['id'];
$n = 2; // Start at -2 for conflicting custom IDs.
while ( is_registered_sidebar( $_args['id'] ) ) {
$_args['id'] = $args['id'] . '-' . $n++;
$n = count( $wp_registered_sidebars );
$_args['id'] = 'sidebar-' . ++$n;
} while ( is_registered_sidebar( $_args['id'] ) );
register_sidebar( $_args );
* Builds the definition for a single sidebar and returns the ID.
* Accepts either a string or an array and then parses that against a set
* of default arguments for the new sidebar. WordPress will automatically
* generate a sidebar ID and name based on the current number of registered
* sidebars if those arguments are not included.
* When allowing for automatic generation of the name and ID parameters, keep
* in mind that the incrementor for your sidebar can change over time depending
* on what other plugins and themes are installed.
* If theme support for 'widgets' has not yet been added when this function is
* called, it will be automatically enabled through the use of add_theme_support()
* @since 5.6.0 Added the `before_sidebar` and `after_sidebar` arguments.
* @global array $wp_registered_sidebars Registered sidebars.
* @param array|string $args {
* Optional. Array or string of arguments for the sidebar being registered.
* @type string $name The name or title of the sidebar displayed in the Widgets
* interface. Default 'Sidebar $instance'.
* @type string $id The unique identifier by which the sidebar will be called.
* Default 'sidebar-$instance'.
* @type string $description Description of the sidebar, displayed in the Widgets interface.
* @type string $class Extra CSS class to assign to the sidebar in the Widgets interface.
* @type string $before_widget HTML content to prepend to each widget's HTML output when assigned
* to this sidebar. Receives the widget's ID attribute as `%1$s`
* and class name as `%2$s`. Default is an opening list item element.
* @type string $after_widget HTML content to append to each widget's HTML output when assigned
* to this sidebar. Default is a closing list item element.
* @type string $before_title HTML content to prepend to the sidebar title when displayed.
* Default is an opening h2 element.
* @type string $after_title HTML content to append to the sidebar title when displayed.
* Default is a closing h2 element.
* @type string $before_sidebar HTML content to prepend to the sidebar when displayed.
* Receives the `$id` argument as `%1$s` and `$class` as `%2$s`.
* Outputs after the {@see 'dynamic_sidebar_before'} action.
* @type string $after_sidebar HTML content to append to the sidebar when displayed.
* Outputs before the {@see 'dynamic_sidebar_after'} action.
* @return string Sidebar ID added to $wp_registered_sidebars global.
function register_sidebar( $args = array() ) {
global $wp_registered_sidebars;
$i = count( $wp_registered_sidebars ) + 1;
$id_is_empty = empty( $args['id'] );
/* translators: %d: Sidebar number. */
'name' => sprintf( __( 'Sidebar %d' ), $i ),
'before_widget' => '<li id="%1$s" class="widget %2$s">',
'after_widget' => "</li>\n",
'before_title' => '<h2 class="widgettitle">',
'after_title' => "</h2>\n",
* Filters the sidebar default arguments.
* @see register_sidebar()
* @param array $defaults The default sidebar arguments.
$sidebar = wp_parse_args( $args, apply_filters( 'register_sidebar_defaults', $defaults ) );
/* translators: 1: The 'id' argument, 2: Sidebar name, 3: Recommended 'id' value. */
__( 'No %1$s was set in the arguments array for the "%2$s" sidebar. Defaulting to "%3$s". Manually set the %1$s to "%3$s" to silence this notice and keep existing sidebar content.' ),
$wp_registered_sidebars[ $sidebar['id'] ] = $sidebar;
add_theme_support( 'widgets' );
* Fires once a sidebar has been registered.
* @param array $sidebar Parsed arguments for the registered sidebar.
do_action( 'register_sidebar', $sidebar );
* Removes a sidebar from the list.
* @global array $wp_registered_sidebars Registered sidebars.
* @param string|int $sidebar_id The ID of the sidebar when it was registered.
function unregister_sidebar( $sidebar_id ) {
global $wp_registered_sidebars;
unset( $wp_registered_sidebars[ $sidebar_id ] );
* Checks if a sidebar is registered.
* @global array $wp_registered_sidebars Registered sidebars.
* @param string|int $sidebar_id The ID of the sidebar when it was registered.
* @return bool True if the sidebar is registered, false otherwise.
function is_registered_sidebar( $sidebar_id ) {
global $wp_registered_sidebars;
return isset( $wp_registered_sidebars[ $sidebar_id ] );
* Register an instance of a widget.
* The default widget option is 'classname' that can be overridden.
* The function can also be used to un-register widgets when `$output_callback`
* parameter is an empty string.
* @since 5.3.0 Formalized the existing and already documented `...$params` parameter
* by adding it to the function signature.
* @global array $wp_registered_widgets Uses stored registered widgets.
* @global array $wp_registered_widget_controls Stores the registered widget controls (options).
* @global array $wp_registered_widget_updates
* @global array $_wp_deprecated_widgets_callbacks
* @param int|string $id Widget ID.
* @param string $name Widget display title.
* @param callable $output_callback Run when widget is called.
* @param array $options {
* Optional. An array of supplementary widget options for the instance.
* @type string $classname Class name for the widget's HTML container. Default is a shortened
* version of the output callback name.
* @type string $description Widget description for display in the widget administration
* @param mixed ...$params Optional additional parameters to pass to the callback function when it's called.
function wp_register_sidebar_widget( $id, $name, $output_callback, $options = array(), ...$params ) {
global $wp_registered_widgets, $wp_registered_widget_controls, $wp_registered_widget_updates, $_wp_deprecated_widgets_callbacks;
if ( empty( $output_callback ) ) {
unset( $wp_registered_widgets[ $id ] );
$id_base = _get_widget_id_base( $id );
if ( in_array( $output_callback, $_wp_deprecated_widgets_callbacks, true ) && ! is_callable( $output_callback ) ) {
unset( $wp_registered_widget_controls[ $id ] );
unset( $wp_registered_widget_updates[ $id_base ] );
$defaults = array( 'classname' => $output_callback );
$options = wp_parse_args( $options, $defaults );
'callback' => $output_callback,
$widget = array_merge( $widget, $options );
if ( is_callable( $output_callback ) && ( ! isset( $wp_registered_widgets[ $id ] ) || did_action( 'widgets_init' ) ) ) {
* Fires once for each registered widget.
* @param array $widget An array of default widget arguments.
do_action( 'wp_register_sidebar_widget', $widget );
$wp_registered_widgets[ $id ] = $widget;
* Retrieve description for widget.
* When registering widgets, the options can also include 'description' that
* describes the widget for display on the widget administration panel or
* @global array $wp_registered_widgets
* @param int|string $id Widget ID.
* @return string|void Widget description, if available.
function wp_widget_description( $id ) {
if ( ! is_scalar( $id ) ) {
global $wp_registered_widgets;
if ( isset( $wp_registered_widgets[ $id ]['description'] ) ) {
return esc_html( $wp_registered_widgets[ $id ]['description'] );
* Retrieve description for a sidebar.
* When registering sidebars a 'description' parameter can be included that
* describes the sidebar for display on the widget administration panel.
* @global array $wp_registered_sidebars Registered sidebars.
* @param string $id sidebar ID.
* @return string|void Sidebar description, if available.
function wp_sidebar_description( $id ) {
if ( ! is_scalar( $id ) ) {
global $wp_registered_sidebars;
if ( isset( $wp_registered_sidebars[ $id ]['description'] ) ) {
return wp_kses( $wp_registered_sidebars[ $id ]['description'], 'sidebar_description' );
* Remove widget from sidebar.
* @param int|string $id Widget ID.
function wp_unregister_sidebar_widget( $id ) {
* Fires just before a widget is removed from a sidebar.
* @param int $id The widget ID.
do_action( 'wp_unregister_sidebar_widget', $id );
wp_register_sidebar_widget( $id, '', '' );
wp_unregister_widget_control( $id );
* Registers widget control callback for customizing options.
* @since 5.3.0 Formalized the existing and already documented `...$params` parameter
* by adding it to the function signature.
* @global array $wp_registered_widget_controls