woocommerce_order_status_changed │ action-hook │ WC 1.0

Usage

add_action( 'woocommerce_order_status_changed', 'wp_kama_woocommerce_order_status_changed_action', 10, 4 );

/**
 * Function for `woocommerce_order_status_changed` action-hook.
 * 
 * @param  $id                     
 * @param  $status_transition_from 
 * @param  $status_transition_to   
 * @param  $that                   
 *
 * @return void
 */
function wp_kama_woocommerce_order_status_changed_action( $id, $status_transition_from, $status_transition_to, $that ){

	// action...
}

$id

-

$status_transition_from

-

$status_transition_to

-

$that

-

Where the hook is called

do_action( 'woocommerce_order_status_changed', $this->get_id(), $status_transition['from'], $status_transition['to'], $this );

Where the hook is used in WooCommerce

add_action( 'woocommerce_order_status_changed', array( $this, 'track_order_status_change' ), 10, 3 );