How do I cancel a payment in my payment driver?

If capturing of the payment is done at a later stage to the initial authorisation, the payment gateway should support the ability to cancel the transaction. The driver should therefore implement a cancel method.

The cancel method should return a Aero\Payment\Responses\PaymentResponse instance.

public function cancel(Payment $payment)
{
    $response = new \Aero\Payment\Responses\PaymentResponse();

    // request to cancel the transaction using the 3rd party API
    $capture = AcmePaymentsInc::cancelTransaction($payment->reference);

    // check if the transaction status is "cancelled"
    if ($capture->status !== AcmePaymentsInc::STATUS_CANCELLED) {
        // set an error on the response
        $response->setError('The transaction could not be cancelled.');

        return $response;
    }

    // internally mark the aero payment as cancelled
    $payment->cancel();

    // mark the response as successful
    $response->setSuccessful(true);

    return $response;
}