PayPal Receipt not showing Description information using SetExpressCheckout - paypal

Question

I am using PayPal's API to process a payment using SetExpressCheckout method.
$requestParams = array(
'RETURNURL' => 'SUCCESS_PAGE_URL',
'CANCELURL' => 'CANCE_PAGE_URL'
);
$orderParams = array(
'PAYMENTREQUEST_0_AMT' => $price,
'PAYMENTREQUEST_0_SHIPPINGAMT' => '0',
'PAYMENTREQUEST_0_CURRENCYCODE' => 'USD',
'PAYMENTREQUEST_0_ITEMAMT' => $price
);
$item = array(
'L_PAYMENTREQUEST_0_NAME0' => $item_name,
'L_PAYMENTREQUEST_0_DESC0' => $item_description,
'L_PAYMENTREQUEST_0_AMT0' => $price,
'L_PAYMENTREQUEST_0_QTY0' => '1'
);
$paypal = new Paypal();
$response = $paypal -> request('SetExpressCheckout',$requestParams + $orderParams + $item);
It all works great, but even though the description is showing in the PayPal's checkout page, the email receipt that I get is missing the description information.
Does anyone know what how I can get the description to show on the receipt?

Answer 1

Figured it out. When the SetExpressCheckout is done and returns "Success" it gets redirected to PayPal, after which it goes back to your specified RETURNURL. On this RETURNURL page, for DoExpressCheckoutPayment, you need to specify the order details, this is what shows up in the invoice. Here is the code:
// Complete the checkout transaction
$requestParams = array(
'TOKEN' => $_GET['token'],
'PAYMENTACTION' => 'Sale',
'PAYERID' => $_GET['PayerID'],
'PAYMENTREQUEST_0_AMT' => '1', // Same amount as in the original request
'PAYMENTREQUEST_0_CURRENCYCODE' => 'USD' // Same currency as the original request
);
$item = array(
'L_PAYMENTREQUEST_0_NAME0' => $name,
'L_PAYMENTREQUEST_0_DESC0' => $desc, // <-- this is the description
'L_PAYMENTREQUEST_0_AMT0' => $price,
'L_PAYMENTREQUEST_0_QTY0' => '1'
);
$response = $paypal -> request('DoExpressCheckoutPayment',$requestParams + $item);