Retrieving POST Data from AJAX Call to PHP

Question

Three days had passed and still having problems to get this things work. This AJAX Call on my js file seems working when it comes to sending JSON data:

 var _lname = $('#ptLastName').val();
 var _fname = $('#ptFirstName').val();
 var _mname = $('#ptMiddleName').val();
 var _gender = $('#ptGender').val();
 var _bday = $('input[name="birthdate"]').val(); // $('#ptBirthDate').val();
 var _ssn = $('#ptSSN').val();

 $.ajax({
          type: "POST",
          url: ".././CheckPerson.php",
          data: "{'lastName':'" + _lname + "','firstName':'" + _fname + "','middleName':'" + _mname + "'}",
          contentType: "application/json; charset=utf-8",
          dataType: "json",
          success: function (response) {
          var res = response.d;
          if (res == true) {
               jAlert('Person Name already exists!', 'Error');
               return;
          } 
})

but in my PHP file:

$lastname = json_decode($_POST['lastName']);
$firstname = json_decode($_POST['firstName']);
$middlename = json_decode($_POST['middleName']);
$response = array();

mysql_connect ("*****", "****") or die ('Error: ' . mysql_error());
mysql_select_db ("********");

$query = "SELECT Lastname, Firstname, MiddleName FROM tbl_people WHERE Lastname = '$lastname' || Firstname = '$firstname' || MiddleName = '$middlename'";

$result = mysql_query($query);

$row = mysql_fetch_array($result);

    if ($row) {     
        $response = json_encode(array('d' => true, 'test' => $lastname)); 
    }
    else { 
    $response = json_encode(array('d' => false, 'test' => $lastname));
    }
echo $response;
print json_encode($_POST);

some error from firebug console says:

<br />
<b>Notice</b>:  Undefined index: lastName in <b>C:\xampp\htdocs\..\CheckPerson.php</b> on line <b>2</b><br />
<br />
<b>Notice</b>:  Undefined index: firstName in <b>C:\xampp\htdocs\..\CheckPerson.php</b> on line <b>3</b><br />
<br />
<b>Notice</b>:  Undefined index: middleName in <b>C:\xampp\htdocs\..\CheckPerson.php</b> on line <b>4</b><br />
{"d":false,"test":null}[]

i believe that json_decode() is working fine in my php file but $_POST[''] can't recognize my posted data from my ajax call w/c variables had been declared:

data: "{'lastName':'" + _lname + "','firstName':'" + _fname + "','middleName':'" + _mname + "'}",

I believe I am doing right with my codes seems i had read many questions here and done what they had said but don't know why the error occurred. Is there any problem/bug you had seen? please tell me.

Does this answer your question? ["Notice: Undefined variable", "Notice: Undefined index", and "Notice: Undefined offset" using PHP](https://stackoverflow.com/questions/4261133/notice-undefined-variable-notice-undefined-index-and-notice-undefined) — Nico Haase, May 27 '20 at 14:39

score 13 · Accepted Answer · edited Jan 31 '21 at 16:53

13

Can you see the ajax request data using the firebug console?

You cannot get the lastname, firstname from $_POST. It's inside the json string. First, you have to get the data using

 $data = $_POST['data'] or $_REQUEST['data']

Then, decode the $data using json_decode() and access your attributes.

json_decode($data);

edited Jan 31 '21 at 16:53

Syscall

19,327
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answered Nov 23 '11 at 03:29

Rakhitha Nimesh

1,393
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I can see it. It displays the json data on the firebag console.I think ajax works fine with that. I want to upload the screenshot of it, for you guys to see it but my reputation is low for me to have the privilege. json data shows that: firstName "inputtedfirstname" lastName "inputtedlastname" middleName "inputtedmiddlename" but my php file can't get those values using json_decode($_POST['lastName']). where do you think is the problem. – Noel Delos Santos Perez Nov 23 '11 at 04:57
I'd tried it, but it also returned 'data' as Undefined index. I really don't why '$_POST' can't get the posted data. I believe that it should even read the attributes, but it didn't. I'm really having a bad time in here. – Noel Delos Santos Perez Nov 23 '11 at 11:39
1

$.post('.././CheckPerson.php', {data: dataString}, function(res){ }); try sending data using this method – Rakhitha Nimesh Nov 23 '11 at 11:43
It just work. I can now access the data in my php file. But I think I have to delete my ajax function now and start coding again, since those codes doesn't work for me or maybe I just can't make it work. thanks a lot. – Noel Delos Santos Perez Nov 23 '11 at 12:21
Did my last option worked? $.post('.././CheckPerson.php', {data: dataString}, function(res){ }); – Rakhitha Nimesh Nov 23 '11 at 16:51
1

Yup. I've tried $.post('.././CheckPerson.php', {data: dataString}, function(res){ }); just like what you had said. But now the data is not json data. I'm still looking for ways if I can use json data returned by ajax in my php file, but I think i'm good with $.post(); for now. Thanks again for the help. – Noel Delos Santos Perez Nov 24 '11 at 05:20

score 10 · Answer 2 · edited Feb 10 '16 at 10:19

10

$post = file_get_contents('php://input');

edited Feb 10 '16 at 10:19

Natalie Hedström

2,607
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answered Feb 10 '16 at 07:33

Lapi

119
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2

1

Please add some explanation to your answer such that others can learn from it – Nico Haase May 27 '20 at 14:40

score 0 · Answer 3 · answered May 23 '19 at 08:04

0

instead of this

data: "{'lastName':'" + _lname + "','firstName':'" + _fname +
"','middleName':'" + _mname + "'}",

use this

data: {lastName:_lname,firstName:_fname,middleName:_mname},

answered May 23 '19 at 08:04

Jackson Harry

308
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Please add some explanation to your answer such that others can learn from it – Nico Haase May 27 '20 at 14:40

badr · Answer 4 · 2021-01-31T17:24:09.790

0

try with this solution

$lastname = isset($_POST['lastName'])?json_decode($_POST['lastName']):null; $firstname =isset($_POST['firstname'])?json_decode($_POST['firstname']):null; $middlename=isset($_POST['middlename'])?json_decode($_POST['middlename']):null;

edited Jan 31 '21 at 17:24

answered Jan 31 '21 at 16:38

badr

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1

Retrieving POST Data from AJAX Call to PHP

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