Intercept payment method change

Question

I am working on a custom extension where I need to call an observer when any payment method is selected from the available payment method list on the frontend checkout page.

Unfortunately, I didn't find one, but it seems that I rather need to subscribe to quote.paymentMethod.

Can anyone tell me if there is an event for this that could be observed or should I subscribe to quote.paymentMethod?

PS. I need to recalculate the totals/save the quote once a payment method is selected.

Answer 1

1)The Magento\Checkout\Model\PaymentInformationManagement class implements savePaymentInformationAndPlaceOrder() method from the Magento\Checkout\Api\PaymentInformationManagementInterface interface. There is also similar to the PaymentInformationManagement class, the Magento\Checkout\Model\GuestPaymentInformationManagement class responsible for guest checkout.

public function savePaymentInformationAndPlaceOrder(
    $cartId,
    $email,
    \Magento\Quote\Api\Data\PaymentInterface $paymentMethod,
    \Magento\Quote\Api\Data\AddressInterface $billingAddress = null
) {
    $this->savePaymentInformation($cartId, $email, $paymentMethod, $billingAddress);
    try {
        $orderId = $this->cartManagement->placeOrder($cartId);
    } catch (\Exception $e) {
        throw new CouldNotSaveException(
            __('An error occurred on the server. Please try to place the order again.'),
            $e
        );
    }
    return $orderId;
}