Few Google Checkout Questions - php

Question

I am planning to integrate a Google Checkout payment system on a social networking website. The idea is that members can buy "tokens" for real money (which are sort of the website currency) and then they can buy access to some extra content on the website etc.
What I want to do is create a Google Checkout button that takes a member to the checkout page where he pays with his credit or debit card. What I want is the Google Checkout to notify notify my server whether the purchase of tokens was successful (if the credit/debit card was charged) so I can update the local database.
The website is coded in PHP/MySQL.
I have downloaded the sample PHP code from here: code.google.com/p/google-checkout-php-sample-code/wiki/Documentation
I know how to create a Google checkout button and I have also placed the responsehandlerdemo.php file on my server. This is the file the Google Checkout is supposed to send response to (of course I set the path to the file in Google merchant account).
Now in the response handler file there is a switch block with several case statements. Which one means that the payment was successful and I can add tokens to the member account in the local database?
switch ($root) {
case "request-received": {
break;
}
case "error": {
break;
}
case "diagnosis": {
break;
}
case "checkout-redirect": {
break;
}
case "merchant-calculation-callback": {
// Create the results and send it
$merchant_calc = new GoogleMerchantCalculations($currency);
// Loop through the list of address ids from the callback
$addresses = get_arr_result($data[$root]['calculate']['addresses']['anonymous-address']);
foreach($addresses as $curr_address) {
$curr_id = $curr_address['id'];
$country = $curr_address['country-code']['VALUE'];
$city = $curr_address['city']['VALUE'];
$region = $curr_address['region']['VALUE'];
$postal_code = $curr_address['postal-code']['VALUE'];
// Loop through each shipping method if merchant-calculated shipping
// support is to be provided
if(isset($data[$root]['calculate']['shipping'])) {
$shipping = get_arr_result($data[$root]['calculate']['shipping']['method']);
foreach($shipping as $curr_ship) {
$name = $curr_ship['name'];
//Compute the price for this shipping method and address id
$price = 12; // Modify this to get the actual price
$shippable = "true"; // Modify this as required
$merchant_result = new GoogleResult($curr_id);
$merchant_result->SetShippingDetails($name, $price, $shippable);
if($data[$root]['calculate']['tax']['VALUE'] == "true") {
//Compute tax for this address id and shipping type
$amount = 15; // Modify this to the actual tax value
$merchant_result->SetTaxDetails($amount);
}
if(isset($data[$root]['calculate']['merchant-code-strings']
['merchant-code-string'])) {
$codes = get_arr_result($data[$root]['calculate']['merchant-code-strings']
['merchant-code-string']);
foreach($codes as $curr_code) {
//Update this data as required to set whether the coupon is valid, the code and the amount
$coupons = new GoogleCoupons("true", $curr_code['code'], 5, "test2");
$merchant_result->AddCoupons($coupons);
}
}
$merchant_calc->AddResult($merchant_result);
}
} else {
$merchant_result = new GoogleResult($curr_id);
if($data[$root]['calculate']['tax']['VALUE'] == "true") {
//Compute tax for this address id and shipping type
$amount = 15; // Modify this to the actual tax value
$merchant_result->SetTaxDetails($amount);
}
$codes = get_arr_result($data[$root]['calculate']['merchant-code-strings']
['merchant-code-string']);
foreach($codes as $curr_code) {
//Update this data as required to set whether the coupon is valid, the code and the amount
$coupons = new GoogleCoupons("true", $curr_code['code'], 5, "test2");
$merchant_result->AddCoupons($coupons);
}
$merchant_calc->AddResult($merchant_result);
}
}
$Gresponse->ProcessMerchantCalculations($merchant_calc);
break;
}
case "new-order-notification": {
$Gresponse->SendAck();
break;
}
case "order-state-change-notification": {
$Gresponse->SendAck();
$new_financial_state = $data[$root]['new-financial-order-state']['VALUE'];
$new_fulfillment_order = $data[$root]['new-fulfillment-order-state']['VALUE'];
switch($new_financial_state) {
case 'REVIEWING': {
break;
}
case 'CHARGEABLE': {
//$Grequest->SendProcessOrder($data[$root]['google-order-number']['VALUE']);
//$Grequest->SendChargeOrder($data[$root]['google-order-number']['VALUE'],'');
break;
}
case 'CHARGING': {
break;
}
case 'CHARGED': {
break;
}
case 'PAYMENT_DECLINED': {
break;
}
case 'CANCELLED': {
break;
}
case 'CANCELLED_BY_GOOGLE': {
//$Grequest->SendBuyerMessage($data[$root]['google-order-number']['VALUE'],
// "Sorry, your order is cancelled by Google", true);
break;
}
default:
break;
}
switch($new_fulfillment_order) {
case 'NEW': {
break;
}
case 'PROCESSING': {
break;
}
case 'DELIVERED': {
break;
}
case 'WILL_NOT_DELIVER': {
break;
}
default:
break;
}
break;
}
case "charge-amount-notification": {
//$Grequest->SendDeliverOrder($data[$root]['google-order-number']['VALUE'],
// <carrier>, <tracking-number>, <send-email>);
//$Grequest->SendArchiveOrder($data[$root]['google-order-number']['VALUE'] );
$Gresponse->SendAck();
break;
}
case "chargeback-amount-notification": {
$Gresponse->SendAck();
break;
}
case "refund-amount-notification": {
$Gresponse->SendAck();
break;
}
case "risk-information-notification": {
$Gresponse->SendAck();
break;
}
default:
$Gresponse->SendBadRequestStatus("Invalid or not supported Message");
break;
}
I guess that case 'CHARGED' is the one, am I right?
Second question, do I need an SSL certificate to receive response from Google Checkout? According to this I do: groups.google.com/group/google-checkout-api-php/browse_thread/thread/10ce55177281c2b0
But I don's see it mentioned anywhere in the official documentation.
Thank you.

Answer 1

I integrated this into my site over 6 months ago. It's very low volume, but works good so far.
The first thing that you should worry about is 'CHARGEABLE'. This means that the credit card has been approved for the transaction, but it will not actually charge the funds until you take action. In order to send the charge request, simply un-comment the two lines under CHARGEABLE. You can change your settings to make it automatically charge the card in 'settings' > 'preferences', but you might as well just un-comment the 2 lines and leave your options open.
Note that you might want to WAIT for the 'risk-information-notification' and determine if the risk check passed before approving the charge ($data[$root]['risk-information']['eligible-for-protection']['VALUE']). Although, seems you are talking about digital goods the possibility of chargebacks might not matter to you.
At some point, I'm sure you should also check that the request has sufficient information for you to link the funds to some account before you charge it, but maybe this is just my paranoia.
The other state that I use is 'charge-amount-notification'. It's completely possible that there is a way to use 'CHARGED', but I don't that 'CHARGED' provides an amount that was actually charged. ($amount_charged = $data[$root]['total-charge-amount']['VALUE'];)
As for the SSL, if you check the location where you enter the callback URL it states the following:
"Specify a URL for Google to notify you of new orders and changes in order state. You must provide the URL of a server running 128-bit SSLv3 or TLS"
Answer to your comment:
I do this under 'new_order_notification', not sure if you can do it elsewhere.
$items = get_arr_result( $data[$root]['shopping-cart']['items']['item'] );
foreach( $items as $item ) {
if( !isset ( $item['merchant-item-id']['VALUE'] ) ) {
//error
return;
}
$request_item_id = $item['merchant-item-id']['VALUE'];
//save your item id with corresponding google order id for further processing
}

Answer 2

Yes, "Chargeable" is the first thing you need to look at in a Google Checkout order. When you click "Chargeable", a window will pop up for you to actually charge the order BUT be sure that the "Eligible for Protection" is True before actually charging the order. This ensure you that the payment is covered by Google payment guarantee. You can actually see it in the "Buyer Credit Verification" section in Google Checkout.