PayPal IPN returns INVALID on Sandbox with Google Script

Question

This standalone Google Script web-service always returns INVALID from PayPal (resp = INVALID). The PayPal IPN simulator shows a message that the handshake was successful.

What am I missing?

function doPost(e) {

  var isProduction = false;

  //if(typeof e == 'undefined')
    //return ContentService.createTextOutput(JSON.stringify(e.parameter));

  var strSandbox  = "https://www.sandbox.paypal.com/cgi-bin/webscr"
  var strLive = "https://www.paypal.com/cgi-bin/webscr"
  var paypalURL = strSandbox

  if (isProduction)  paypalURL = strLive;
  var payload = "cmd=_notify-validate&" + e.postData.contents;


  var options =
    {
      "method" : "post",
      "payload" : payload
    };

  var resp = UrlFetchApp.fetch(paypalURL, options);
}

http://stackoverflow.com/questions/1485832/paypal-sandbox-ipn-return-invalid have you checked this ? — Deep Kakkar, Oct 06 '16 at 10:14

score 1 · Answer 1 · answered Oct 06 '16 at 10:05

After getting everything to work, I'm offering here my working implementation skeleton:

function doPost(e) {

  var isProduction = false;

  //if(typeof e == 'undefined')
    //return ContentService.createTextOutput(JSON.stringify(e.parameter));

  var strSimulator  = "https://www.sandbox.paypal.com/cgi-bin/webscr"
  var strLive = "https://www.paypal.com/cgi-bin/webscr"
  var paypalURL = strSimulator

  if (isProduction)  paypalURL = strLive;
  var payload = "cmd=_notify-validate&" + e.postData.contents;
  payload = payload.replace("+", "%2B");

  var options =
    {
      "method" : "post",
      "payload" : payload,
    };

  var resp = UrlFetchApp.fetch(paypalURL, options); //Handshake with PayPal - send acknowledgement and get VERIFIED or INVALID response

  if (resp == 'VERIFIED') {
    if (e.parameter.payment_status  == 'Completed') {
      if (e.parameter.receiver_email == 'receiver@email.com') {
        //Convert to reference currency (USD) if paid in any other currency
        var exchangeRate = 1; 
        if ((e.parameter.exchange_rate)) {
          exchangeRate = parseFloat(e.parameter.exchange_rate);
        }  
        var paidUSD = isPaymentValid(parseFloat(e.parameter.mc_gross), e.parameter.mc_currency, exchangeRate); //Convert paid amound to reference currency (USD)
        if (paidUSD == 0.0) {
          //My function returns 0.0 if product cost not found in my DB. I raise some notification here to check it out
          return false;
        }
        if (paidUSD > 0.0) {
          //All validated - can process the payment
          var processSuccess = processDownloadRequest(e);

          if (!(processSuccess)) {
            //Process of payment failed - raise notification to check it out
          }
        } else {
          //Payment does not equal expected purchase value
        }
      } else {
       //Request did not originate from my PayPal account 
      }
    } else {
     //Payment status not Completed 
    }
  } else
  {
   //PayPal response INVALID 
  }
}

PayPal IPN returns INVALID on Sandbox with Google Script

1 Answers1