Destroy session upon refresh

Question

I am trying to destroy the session information upon refresh. The problem here is that everytime I refresh, the data still appears on the table. How do i set the table data to null upon refresh?

<?php
        $value = $_SESSION["data"];
        $query = "SELECT * FROM datas WHERE CONCAT(`code`,`name`, `ID`, `cost`) LIKE '%".$value."%'";
        $search = filterTable($query);
    if (isset($_SESSION["data"])) {
       if (basename($_SERVER['PHP_SELF']) != $_SESSION["data"]) {
            session_destroy();
       }
    }
    function filterTable($query)
    {
        $connect = mysqli_connect("localhost", "root", "", "databasename");
        $filter = mysqli_query($connect, $query);
        return $filter;
    }

?>

You can use Javascript here. You can clear your table in 'Document.ready' function. Thus, for each refresh the table will become blank. — Akhter Al Amin, Jul 17 '16 at 06:22
maybe the problem is this condition: if (basename($_SERVER['PHP_SELF']) != $_SESSION["data"]). Try to double check this. — Marko Krstic, Jul 17 '16 at 06:29

score 1 · Answer 1 · answered Jul 17 '16 at 06:30

If you want to clear all session variables after you have retrieved them once, you can use PHPs session_unset() function.

In your code it would be:

$value = $_SESSION["data"];
    $query = "SELECT * FROM datas WHERE CONCAT(`code`,`name`, `ID`, `cost`) LIKE '%".$value."%'";
    $search = filterTable($query);
if (isset($_SESSION["data"])) {
   if (basename($_SERVER['PHP_SELF']) != $_SESSION["data"]) {
        session_unset();
   }
}

This should clear all session data so when the page is refreshed, $value should be null.

You can also try to use unset() to remove the values. E.g.

unset($_SESSION['data']);

hi, unfortunately the session wasn't destroyed :( – xodebox95 Jul 17 '16 at 06:42 — xodebox95, Jul 17 '16 at 06:42

score 0 · Answer 2 · edited May 23 '17 at 10:28

0

one alternative way is to set session as empty array, and that would help you:

$_SESSION = array();

EDIT

did you try first to destroy and then to set empty array like:

session_destroy();
$_SESSION = array();

maybe this post might help you: why session_destroy() not working

edited May 23 '17 at 10:28

Community

1
1

answered Jul 17 '16 at 06:32

Marko Krstic

1,417
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this does't work either, or am I placing it in a wrong order? – xodebox95 Jul 17 '16 at 06:42

score -1 · Answer 3 · edited Aug 30 '18 at 11:20

We cannot unset session variable through javascript or ajax. So we have to pass the control first to php using javascript and ajax. From there you can unset session data :

//put this line of code in that page you are planning to refresh.
window.onbeforeunload = function() {
      if (typeof XMLHttpRequest != "undefined"){
                xmlHttp= new XMLHttpRequest();
                }
                else if (window.ActiveXObject){
                    xmlHttp= new ActiveXObject("Microsoft.XMLHTTP");
                }
                if (xmlHttp==null){
                    alert("Browser does not support XMLHTTP Request")
                    return;
                }
                var base_url="<?php echo base_url(); ?>"
                var url=base_url + 'controller/function_name';
               // url +=id;
                xmlHttp.onreadystatechange = stateChange;
                xmlHttp.open("GET", url, true);
                xmlHttp.send(null);

  };

//your function in php will be 

public function function_name(){

        $newdata =  array(

                            'session_variable' =>0       
                    );

        $this->session->set_userdata($newdata);
    }

Destroy session upon refresh

3 Answers3