Change invoice status to paid programmatically

Question

How can we programmatically change the status of an invoice to Paid for an order with an offline payment method (eg bank transfer or cash)?

I have tried using the following capture method but this still leaves the invoice as Pending:

$order->load($_POST['order']);
$order->getPayment()->capture();
$order->save();

So how can we update an invoice with an offline payment method to Paid?

Answer 1

Have you tried this?

$invoice = Mage::getModel('sales/order_invoice')->load(...id_of_invoice...);
$invoice->pay()->save();