WordPress at a glance
filter is not described

is_active_sidebar filter-hook . WP 3.9.0

Filters whether a dynamic sidebar is considered "active".


add_filter( 'is_active_sidebar', 'filter_function_name_8079', 10, 2 );
function filter_function_name_8079( $is_active_sidebar, $index ){
	// filter...

	return $is_active_sidebar;
Whether or not the sidebar should be considered "active". In other words, whether the sidebar contains any widgets.
Index, name, or ID of the dynamic sidebar.


Since 3.9.0 Introduced.

Where the hook is called

wp-includes/widgets.php 911
return apply_filters( 'is_active_sidebar', $is_active_sidebar, $index );

Where the hook is used (in WP core)

wp-includes/class-wp-customize-widgets.php 123
add_filter( 'is_active_sidebar', array( $this, 'tally_sidebars_via_is_active_sidebar_calls' ), 10, 2 );