AJAX POST not working, php doesn't create session

Question

I want to send id of element to php and create session for this.

This is piece from php file:

<?php
$sql = "SELECT id FROM products";
$result = mysqli_query($con,$sql);

while($row = mysqli_fetch_array($result)) {
?>
    <tr class="table-manufacture-tr">
    <td class="table-manufacture-td-statys">
        <div class="warehouse-window-content-dropdown-plus2 plus">
           <a class="open_item" data-id=<?php echo "\"".$row['p_id']."\"";?> 
            style="text-decoration: none; color: #D3D3D3;">Click</a>
        </div>
    </td>
    </tr>
<?php
}
?>

And in this file javascript code:

$(document).on('click', '.open_item', function(event){

        var data_item = this.getAttribute("data-id");

        $.ajax({
            url: 'get_id.php',
            type: 'POST',
            data-type: 'json',
            data: { id: data_item },
            contentType: 'application/x-www-form-urlencoded',
            success: function(data){
                console.log(data);
            },
            error: function(){
                console.log("not working");
            }
        });
    });

This is get_id.php:

<?php
    session_start();
    $_SESSION['item_id'] = json_encode($_POST);
    header("Content-Type: application/json", true);
?>

I have tried also without content types and without json. "var data_item" prints id correct, but php doesn't create session and in console also clear(nothing).

Answer 1

The reason that you are not getting data in session is, you are not assigning proper value to session. Also it should be json_decode not json_encode .

replace

$_SESSION['item_id'] = json_encode($_POST);

with

if (!empty($_POST['id'])) {
    $_SESSION['item_id'] = json_decode($_POST['id']); // use json_decode
}

Answer 2

It seems to me that you are making some small mistake in your code like you are echoing $row['p_id'] while your query should return id instead p_id also you are making mistake in ajax you are sending data-type JavaScript assuming your code is subtracting so try to use this code i code below.

// modify your php code
<?php
$sql = "SELECT id FROM products";
$result = mysqli_query($con,$sql);

while($row = mysqli_fetch_assoc($result)) { ?>
  <tr class="table-manufacture-tr">
      <td class="table-manufacture-td-statys">
        <div class="warehouse-window-content-dropdown-plus2 plus">
          <a class="open_item" data-id=<?php echo "\"".$row['id']."\"";?> 
          style="text-decoration: none; color: #D3D3D3;">Click</a>
        </div>
      </td>
  </tr>
<?php } ?>

// modify your jQuery
$(document).on('click', '.open_item', function(event){

    var data_item = $(this).data("id");

    $.ajax({
        url: 'get_id.php',
        type: 'POST',
        dataType: 'json',
        data: { id: data_item },
        success: function(data){
            console.log(data);
        },
        error: function(){
            console.log("not working");
        }
    });
});


<?php
  session_start();
  header("Content-Type: application/json", true);
  $_SESSION['item_id'] = json_encode($_POST["id"]);
  echo json_encode(['data_id' => $_SESSION['item_id']]);
?>

Answer 3

You can use

$_SESSION['item_id'] = json_encode($_POST['id']);

instead of

$_SESSION['item_id'] = json_encode($_POST);

this will work fine.

Answer 4

I don't know what you are trying to do, but from your JS, it looks like that you are expecting that the PHP script --which you post some data to it-- to return a json with the data you have just posted in it. In that case, try this, change your get_id.php to be like:

<?php
    session_start();
    $_SESSION['item_id'] = json_encode($_POST);
    header("Content-Type: application/json", true);
    echo $_SESSION['item_id'];
?>

Answer 5

I'd troubleshoot this by making sure the click handler is actually going off. Put alert("clicked"); as the first thing in the in the click handler to make sure.

For the meantime, remove the contentType in the json call. Also remove the dataType (data-type) entirely. On the php side, replace the header() line so (as mentioned) the php is just:

session_start();
$_SESSION['item_id'] = $_POST["id"];
echo $_SESSION['item_id'];

Do not use json_encode/decode right now. From your code, it is not needed.