after_switch_theme action-hook . WP 3.3.0

Fires on the first WP load after a theme switch if the old theme still exists.

This action fires multiple times and the parameters differs according to the context, if the old theme exists or not. If the old theme is missing, the parameter will be the slug of the old theme.

Usage

add_action( 'after_switch_theme', 'action_function_name_8031', 10, 2 );
function action_function_name_8031( $old_name, $old_theme ){
	// action...
}

$old_name(string)

Old theme name.

$old_theme(WP_Theme)

WP_Theme instance of the old theme.

Changelog

Where the hook is called

do_action( 'after_switch_theme', $old_theme->get( 'Name' ), $old_theme );

do_action( 'after_switch_theme', $stylesheet, $old_theme );

Where in WP core the hook is used

add_action( 'after_switch_theme', '_wp_menus_changed' );

add_action( 'after_switch_theme', '_wp_sidebars_changed' );

remove_action( 'after_switch_theme', '_wp_menus_changed' );

remove_action( 'after_switch_theme', '_wp_sidebars_changed' );