AJAX request not working as expected on first call

Question

I am using jQuery AJAX for my login system.

<script src="http://code.jquery.com/jquery-1.11.3.js" type="text/javascript"></script>
<script src="http://code.jquery.com/jquery.session.js" type="text/javascript"></script>
<script type="text/javascript">
  function Login() {
    var postData = JSON.stringify({
      "username": $("#txtUsername").val(),
      "password": $("#txtPassword").val(),
      "linenumber": $("#ddlLineNum").val()
    });

    $.ajax({
      type: "POST",
      url: "frmLogin.aspx/MyMethod",
      data: postData,
      contentType: "application/json; charset=utf-8",
      success: callbackfunction,
      error: function(msg) {
        alert('ERROR');
      }
    });
  }

  function callbackfunction(result) {
    alert('in call back method');
    if (result.d == "WrongPassword") {
      alert(result.d);
    }

    if (result.d == "Currect Password") {
      alert(username);
      //$.session.set('UserName',username);
      //$.session.set('lineNumber', linenumber);
      //alert($.session.get("UserName"));
      window.location.href = 'Inventory.aspx';
    }
  }
</script>

If I click on my login button for the first time this callbackfunction is not working (alert('in call back method') is not displaying). When I click for the second time the alert is shown.

Can anyone help me out to fix this issue.

if (username == string.Empty)
  return "UserName is Empty";
if (password == string.Empty)
  return "Password is Empty";
if (linenumber == "Please Select")
  return "Line Number is Empty";

DataTable dtLogin = DBLayer.spUserMasterSelect(username);
if (dtLogin.Rows.Count > 0) {
  if (dtLogin.Rows[0]["PASSWORD"].ToString() != password) {
    return "WrongPassword";
  } else {
    return "Currect Password";
  }
} else {
  return "Invalid UserName";
}

REQUEST AND RESPONSE IS frmlogin.aspx header file is Request URL: http://localhost:57075/frmLogin.aspx Request Method: POST Status Code: 200 OK Remote Address: [::1]:57075 Referrer Policy: no-referrer-when-downgrade Cache-Control: private Content-Encoding: gzip Content-Length: 3698 Content-Type: text/html; charset=utf-8 Date: Mon, 09 Sep 2019 09:44:44 GMT Server: Microsoft-IIS/8.0 Vary: Accept-Encoding X-AspNet-Version: 4.0.30319 X-Powered-By: ASP.NET X-SourceFiles: =?UTF-8?B?RDpcQ3VycmVudCBQcm9qZWN0c1xNVFMtV0NQTVxXQ1BNIE5FVyAtIEpxdWVyeSBhbmQgQWpheFxUQ0lMaVdNU1xmcm1Mb2dpbi5hc3B4?= Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,/;q=0.8,application/signed-exchange;v=b3 Accept-Encoding: gzip, deflate, br Accept-Language: en-US,en;q=0.9 Cache-Control: max-age=0 Connection: keep-alive Content-Length: 559 Content-Type: application/x-www-form-urlencoded Host: localhost:57075 Origin: http://localhost:57075 Referer: http://localhost:57075/frmLogin.aspx Sec-Fetch-Mode: navigate Sec-Fetch-Site: same-origin Sec-Fetch-User: ?1 Upgrade-Insecure-Requests: 1 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.132 Safari/537.36 __LASTFOCUS: __VIEWSTATE: cGCxGPZDpgAFMuHbrg1A53vAaM0BzvQjz7MfEimIFx+HJKP+qBDaZHi1pnNTxGprZm35gQjfw5qALYaMZBThSWH2j2GnHiOjHU5BnC3D+WluwvbeyevsZenrwCBd06esBm49ZCc5MY+RcTNeiwhGRQ== __VIEWSTATEGENERATOR: 0C51E059 __EVENTTARGET: __EVENTARGUMENT: __EVENTVALIDATION: ikyLG2JZUj1pDNj+/nM4K0teZ/HT96A1W0NQ1y2qhTATegzDSkvfPZrk6PyZo7DF6bQFKOEu+/zf+bTdFHz6UqEnzcMvq+mCZhBQK3Wab92NRtB5w4TllqDq3gbdv0pjeyrXWtmfUexxo76PdXEAoZ1sDBFHhqsdzXMwwX62mFLhmiPoYUmwR1iWxky++B4F+rP4jxQtsvhUnJG8qELgzQ== txtUsername: ADMIN txtPassword: ADMIN ddlLineNum: 1

this is for second time Request URL: http://localhost:57075/frmLogin.aspx Request Method: POST Status Code: 200 OK Remote Address: [::1]:57075 Referrer Policy: no-referrer-when-downgrade Cache-Control: private Content-Encoding: gzip Content-Length: 3708 Content-Type: text/html; charset=utf-8 Date: Mon, 09 Sep 2019 09:46:36 GMT Server: Microsoft-IIS/8.0 Vary: Accept-Encoding X-AspNet-Version: 4.0.30319 X-Powered-By: ASP.NET X-SourceFiles: =?UTF-8?B?RDpcQ3VycmVudCBQcm9qZWN0c1xNVFMtV0NQTVxXQ1BNIE5FVyAtIEpxdWVyeSBhbmQgQWpheFxUQ0lMaVdNU1xmcm1Mb2dpbi5hc3B4?= Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,/;q=0.8,application/signed-exchange;v=b3 Accept-Encoding: gzip, deflate, br Accept-Language: en-US,en;q=0.9 Cache-Control: max-age=0 Connection: keep-alive Content-Length: 506 Content-Type: application/x-www-form-urlencoded Host: localhost:57075 Origin: http://localhost:57075 Referer: http://localhost:57075/frmLogin.aspx Sec-Fetch-Mode: navigate Sec-Fetch-Site: same-origin Sec-Fetch-User: ?1 Upgrade-Insecure-Requests: 1 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.132 Safari/537.36 __VIEWSTATE: zG8/UiXsuL3e8xOkmL3OW4uIsVjWX307lugZuGNqFSBzejHQxN86sg9lllvaWrJIJZ6/TRi1lbGpJc9XiurbTZecE0GINMpyzSrrAvaiRmQt8HV1USp55SGw6gF5aVtHtFmkgZe3xFUr06SaXhbiwQ== __VIEWSTATEGENERATOR: 0C51E059 __EVENTVALIDATION: 3rl06ckIZwSoQBBJWRONyuPdNovib37nYRGrZNW1FBCOUf8dsDPSTDUpW8uHMlRTMqd8OPKKXiqaGT/DyI51YJplGnyaoB4E4OuBFX43tL+p4HtbWZf2p8kURyNxUdELR7w1ubkiC0GIkkllT1VqrjmkLeuhnkan7xGgiqjj/V/R++NPQWOD+/B0AM7qJeeheYM2UaLv5ZRuUNc1GnKURg== txtUsername: ADMIN txtPassword: admin ddlLineNum: 1

Have you put breakpoints on the server side and debugged through when the AJAX request is made? — mjwills, Sep 09 '19 at 09:23
Please use Chrome Developer Tools (Network tab) and get the request and response for the first request that doesn't work, and the second one that does. Include all four of them in your question. — mjwills, Sep 09 '19 at 09:23
@mjwills i have debugged server side code. and both time it is returning same result. — sudhakar, Sep 09 '19 at 09:26
https://stackoverflow.com/questions/1054022/best-way-to-store-password-in-database — mjwills, Sep 09 '19 at 09:31
@mjwills i am using encryption for storing the password in the database. — sudhakar, Sep 09 '19 at 09:36
You should be salting and hashing, not encrypting. I'd suggest reading the link. — mjwills, Sep 09 '19 at 09:36
"*I click on my login button for the first time*" - please include relevant markup in your question. — But those new buttons though.., Sep 09 '19 at 09:47
@mjwills i am not able to present request and response data as it is having much lines. but i have analyzed there is no difference — sudhakar, Sep 09 '19 at 10:10
I am 95% sure there is a difference. Nonetheless, we can't help without a [mcve]. — mjwills, Sep 09 '19 at 10:12
Please format your question properly. I've already edited it for you once, I'm not going to do it again. — Rory McCrossan, Sep 09 '19 at 10:17

score -1 · Answer 1 · edited Sep 09 '19 at 16:55

-1

Consider catching a failure from your AJAX post request. It might help troubleshoot for your click on your login button for the first time.

$.ajax({
  type: "POST",
  url: "frmLogin.aspx/MyMethod",
  data: postData,
  contentType: "application/json; charset=utf-8",
  success: callbackfunction,
  failure: failureFxn,
  error: function(msg) {
    alert('ERROR');
  }
});

function failureFxn() {
  console.log('failure');
}

edited Sep 09 '19 at 16:55

Rory McCrossan

331,213
40
305
339

answered Sep 09 '19 at 10:12

Thokozani Msebele

1
1

tried with above code. still no failure . console.log is empty – sudhakar Sep 09 '19 at 10:17
There is no `failure` property of `$.ajax`. There is only the `error` callaback which the OP is already using (although it could be used more effectively by checking what `msg` contains). Please read docs: https://api.jquery.com/jquery.ajax/. – Rory McCrossan Sep 09 '19 at 10:18

AJAX request not working as expected on first call

1 Answers1