Function: Determines whether a given widget is displayed on the front end.

Function: Determines whether the dynamic sidebar is enabled and used by the theme.

Function: Determines whether a sidebar contains widgets.

Function: Retrieve full list of sidebars and their widget instance IDs.

Function: Set the sidebar widget option to update sidebars.

Function: Registers widget control callback for customizing options.

Function: Registers the update callback for a widget.

Function: Registers the form callback for a widget.

Function: Remove control callback for widget.

Function: Display dynamic sidebar.