PayPal: pass the email address to the return/“than

问题:

I've successfully created a small "pay now" button with PayPal IPN and a listener. The button itself is wizard-generated.

After the payment, the user is redirected to a return/"thank you" page on my host.

Everything works as expected, but I need to receive the customer e-mail on the "thank you" page too: how can I do that?

回答1:

You can get the user email using the Payment Data Transfer (PDT), which sends a GET variable named tx to your redirect url.

The tx variable contains a transaction number which you can use to send to a post request to Paypal's server and retrieve the transaction information.

The last time I used PDT was a year ago, but I believe there is a setting in your Paypal account that you need to enable and set a redirect url for this to work.

Here are some links that describes PDT in further detail:

• https://www.paypal.com/us/cgi-bin/webscr?cmd=p/xcl/rec/pdt-techview-outside
• https://cms.paypal.com/us/cgi-bin/?cmd=_render-content&content_ID=developer/howto_html_paymentdatatransfer

Here is an example of how to parse send a post request to Paypal and parse the data. I just dug this up from an old file. So no guarantees that it works. This is based off a script that Paypal uses as an example for php. You can use curl instead, and that's probably the better choice. I think there is some kind of security issue with using fsockopen.

//Paypal will give you a token to use once you enable PDT
$auth_token = 'token';

//Transaction number
$tx_token = $_GET['tx'];

$payPalUrl = ( $dev === true ) ? 'ssl://www.sandbox.paypal.com' : 'ssl://www.paypal.com';

$req = 'cmd=_notify-synch';
$req .= "&tx=$tx_token&at=$auth_token";


$header .= "POST /cgi-bin/webscr HTTP/1.0\r\n";
$header .= "Content-Type: application/x-www-form-urlencoded\r\n";
$header .= "Content-Length: " . strlen($req) . "\r\n\r\n";
$fp = fsockopen ($payPalUrl, 443, $errno, $errstr, 30);

$keyarray = false;

if ( $fp ) {
    fputs ($fp, $header . $req);

    $res = '';
    $headerdone = false;
    while (!feof($fp)) {
        $line = fgets ($fp, 1024);
        if (strcmp($line, "\r\n") == 0) {
            $headerdone = true;
        }
        else if ($headerdone) {
            $res .= $line;
        }
    }

    $lines = explode("\n", $res);

    if (strcmp ($lines[0], "SUCCESS") == 0) {
            //If successful we can now get the data returned in an associative array
        $keyarray = array();
        for ($i=1; $i<count($lines);$i++){
            list($key,$val) = explode("=", $lines[$i]);
            $keyarray[urldecode($key)] = urldecode($val);
        }
    }
}
fclose ($fp);
return $keyarray;