Setting PHP session variables with ajax

Question

Want to change value of SESSION variable "fullname" without refreshing the page.

My implementation using ajax:

Page 1 html:

<input type="text" name="fullname" id="fullname" placeholder="Full name">

<button onclick="setSession()"> GO </button>

Page 1 script:

<script>
function setSession(){
   var fullname = $("#fullname").val();
   var dataString = 'fullname=' + fullname;

   $.ajax({
        type: "POST",
        url: "Page2.php",
        data: dataString,
        cache: false,
        success: function( data ) {
             if(data === 'True'){
                 alert("<?php echo $_SESSION['fullname'];?>");
              }
            }
        });
      }
</script>

And in Page 2:

session_start();
$_SESSION["fullname"] = $_POST["fullname"];
echo 'True';
exit();

It doesn't change the value of the session variable.

Both pages have session_start().

You're alerting the same string literal every time in your success function. alert("<?php echo $_SESSION["fullname"];?>"); This never changes. — bassxzero
– bassxzero, Commented Oct 23, 2017 at 17:15
Your echo is going to run on load of Page 1, not on completion of the ajax request. — Patrick Q
– Patrick Q, Commented Oct 23, 2017 at 17:15
Dude, if you're going to continue to edit your code we cannot know what question we're supposed to answer. — Jay Blanchard
– Jay Blanchard, Commented Oct 23, 2017 at 17:26

Don't Panic · Accepted Answer · 2017-10-23 18:10:54Z

3

Your code should already be changing the value in the PHP session. You just don't have your client-side script set up properly to show that.

Return some kind of indicator in your PHP script:

<?php
// Page2.php

session_start();

$_SESSION["fullname"] = $_POST["fullname"];

echo 'set session fullname to ' . $_POST['fullname'];

Then in your AJAX success function, show that response:

...
success: function( response ) {
    alert(response);
}
...

When you use alert("<?php echo $_SESSION['fullname'];?>"); in your success function, PHP will fill in the $_SESSION['fullname'] value in that alert box once when the page loads, and it will never change until the page is reloaded, even if you do successfully update the session value via AJAX.

edited Oct 23, 2017 at 18:10

answered Oct 23, 2017 at 17:29

Don't Panic

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6 Comments

Jay Blanchard Over a year ago

The OP wants the session data to be updated locally without a page refresh.

Patrick Q Over a year ago

To be fair, I'm not 100% sure the OP completely understands the difference between client-side and server-side and which s/he wants to change.

Don't Panic Over a year ago

@JayBlanchard what do you mean by updated locally? I thought it looked like they were just trying to send a value to be stored in the PHP session, and thought it wasn't working because they kept seeing the constant value that was stored in that alert when the page loaded.

Jay Blanchard Over a year ago

They want the session to be updated in the page sending the AJAX request without a reload. "I want to change the session variable without reloading the page."

dokgu Over a year ago

@JayBlanchard this answer won't really reload the page. The last paragraph really explains the main problem of OP.

|

dokgu · Accepted Answer · 2017-10-23 17:35:42Z

2

Page 1 HTML

<input type="text" name="fullname" id="fullname" placeholder="Full name">
<button onclick="setSession()"> GO </button>

Page 1 Script

<script>
function setSession(){
   $.ajax({
        type: "POST",
        url: "Page2.php",
        data: { fullname: $("#fullname").val() },
        dataType: "json",
        cache: false,
        success: function( data ) {
             alert(data.fullname);
        }
   });
}
</script>

Page 2 PHP Script

session_start();
$_SESSION["fullname"] = $_POST["fullname"];
echo json_encode(array('fullname' => $_SESSION['fullname']));

It's generally a bad idea to mix server-side and client-side scripts together so try to separate your PHP and Javascript logic. They both execute at different times/stages of a page request life-cycle.

edited Oct 23, 2017 at 17:35

answered Oct 23, 2017 at 17:30

dokgu

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Comments

Jay Blanchard · Accepted Answer · 2017-10-23 17:22:44Z

1

First, have you watched the AJAX request / response in the browser's developer tools? Have you included the jQuery library in the project? Are there any errors reported? Are you running this on a web-server?

Second, you're starting a session in a remote page. That session data will not be available in the current page until you reload the current page. In addition you have some wonky quoting in your alert, it should be:

alert("<?php echo $_SESSION['fullname'];?>");

edited Oct 23, 2017 at 17:22

answered Oct 23, 2017 at 17:15

Jay Blanchard

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2 Comments

the_it_crowd Over a year ago

Edited. I want to change the session variable without reloading the page.

Jay Blanchard Over a year ago

You can't get that unless you take something returned to you via AJAX and set the session locally.

AltShiftZero · Accepted Answer · 2017-10-23 17:24:03Z

0

You are setting the variable in JS using PHP Inline coding. You could however echo the session variable in page2 if no post has been set. If you then request page two without any post you can use the response body in JS to get the current set session variable and put it in a JS variable.

Var name;
$.get(‘page2.php’, function(data){ name = data; } );

I’m using the iOS app so above code is not complete but an indication for what can be done.

answered Oct 23, 2017 at 17:24

AltShiftZero

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