Paypal IPN - 检查付款状态是否完成？

Question

我有一个销售网站的电子书,用户可以在购买后下载一本书.我从Paypal收到IPN,据我了解,如果用户选择信用卡作为付款方式,有时付款状态为"进行中"或"正在处理".由于Paypal将在付款完成后重新发送IPN,检查付款状态是否完成的最佳方法是什么,以避免数据库中的重复？

Answer 1

这些是Paypal返回您的IPN侦听器的可能状态

Canceled_Reversal
Completed
Denied
Failed
Refunded
Reversed
Voided
In-Progress
Pending
Processed

您应该检查Completed状态以确保付款已完成.以下是IPN Listener检查不同状态的示例

<?php
    //Build the data to post back to Paypal
    $postback = 'cmd=_notify-validate'; 

    // go through each of the posted vars and add them to the postback variable
    foreach ($_POST as $key => $value) {
    $value = urlencode(stripslashes($value));
    $postback .= "&$key=$value";
    }


    // build the header string to post back to PayPal system to validate
    $header = "POST /cgi-bin/webscr HTTP/1.0\r\n";
    $header .= "Content-Type: application/x-www-form-urlencoded\r\n";
    $header .= "Content-Length: " . strlen($postback) . "\r\n\r\n";

    // Send to paypal or the sandbox depending on whether you're live or developing
    // comment out one of the following lines
    //$fp = fsockopen ('ssl://www.sandbox.paypal.com', 443, $errno, $errstr, 30);//open the connection
    $fp = fsockopen ('ssl://www.paypal.com', 443, $errno, $errstr, 30);
    // or use port 443 for an SSL connection
    //$fp = fsockopen ('ssl://www.paypal.com', 443, $errno, $errstr, 30);

    if (!$fp) 
    {
        // HTTP ERROR Failed to connect
        //error handling or email here
    }
    else // if we've connected OK
    {
        fputs ($fp, $header . $postback);//post the data back
        while (!feof($fp)) 
        {
            $response = fgets ($fp, 1024);

            if (strcmp ($response, "VERIFIED") == 0) //It's verified
            {
                // assign posted variables to local variables, apply urldecode to them all at this point as well, makes things simpler later
                $payment_status = $_POST['payment_status'];//read the payment details and the account holder

                if($payment_status == 'Completed')
                {
                    //Do something
                }
                else if($payment_status == 'Denied' || $payment_status == 'Failed' || $payment_status == 'Refunded' || $payment_status == 'Reversed' || $payment_status == 'Voided')
                {
                    //Do something
                }
                else if($payment_status == 'In-Progress' || $payment_status == 'Pending' || $payment_status == 'Processed')
                {
                    //Do something
                }
                else if($payment_status == 'Canceled_Reversal')
                {
                    //Do something
                }
            }
            else if (strcmp ($response, "INVALID") == 0) 
            { 
                //the Paypal response is INVALID, not VERIFIED
            }
        } //end of while
        fclose ($fp);
    }
?>