I'm writing an observer for the sales_order_invoice_register event, I'd like to get the invoice number that has just saved. I can't find the function for retrieving that ID, none of those commented calls works. Any idea? Here the code
public function foobar($observer){
$order = $observer->getEvent()->getOrder();
$id_order = $order->getRealOrderId();
$id_invoice = $observer->getEvent()->getInvoice(); // the Mage_Sales_Model_Order_Invoice object
//$id_invoice = $id_invoice->getId();
//$id_invoice = $id_invoice->getIncrementId();
//$id_invoice = $id_invoice->getInvoiceId();
//$id_invoice = $id_invoice->getRealIncrementId();
//$id_invoice = $id_invoice->getData('invoice_id');
thanks!