Javascript double popup modal with PHP

Question

Good day,

am trying to use javascript to pop out two modal page on my hotspot login page: eg

1. if the clients device IP + MAC address is present and the clients click CONNECT button Login Modal Page Should Appear.
2. if the clients Device IP + MAC address is not present and the clients click CONNECT button Error Modal Page should Appear like (please Connect From a Hotspot)

i have tried this:

<?php
$mac=$_POST['mac'];
$ip=$_POST['ip'];
 ?>


  <button onclick="connect()" type="button" class="btn btn-info">CONNECT</button>
  <script type="text/javascript">

       function connect()

    {

  $('#login').modal();
 }     

    </script>

the above code show the login modal when the CONNECT button is clicked but i want if the ip and mac address is not present when the clients click CONNECT button Error Modal Should Pop up instead of login modal.

thanks in advace.

Answer 1

You'll have to echo the values from PHP to Javascript. But beware that you need to validate these values first.

Something like this should work:

<?php
// get values from $_POST or default to empty string
$mac = $_POST['mac'] ?? '';
$ip  = $_POST['ip'] ?? '';
?>

<button onclick="connect()" type="button" class="btn btn-info">CONNECT</button>

<script type="text/javascript">

function connect() {
    // pass values as string to javascript variables
    var mac = "<?php echo $mac; ?>";
    var ip = "<?php echo $ip; ?>";

    // mac and ip adresses provided
    if (mac && ip) {
        $("#login").modal();
    }

    // mac or ip adresses missing
    else {
        $("#error").modal();
    }
}

</script>

---

A few things to note:

• This is not secure as I values passed as POST can be tampered with. As a rule of thumb, do not trust anything provided by the client.

• <?php echo... ?> will "print" the values in the document. If you inspect the code in the browser, you'll see something like:

   var mac = "mac-address-passed-as-POST"; var ip = "123.456.78.90";

• You can simplify the echo statements by using the shorthand syntax:

   var mac = "<?= $mac?>"; var ip = "<?= $ip?>";

• To better validate the values you get in the $_POST variable, you could add regex checks in the PHP part. Something like:

   <?php // default values $mac = ''; $ip = ''; // validate mac address if (isset($_POST['mac']) && preg_match('/^([0-9A-Fa-f]{2}[:-]){5}([0-9A-Fa-f]{2})$/', $_POST['mac'])) { $mac = $_POST['mac']; } // validate ip address if (isset($_POST['ip']) && preg_match('/^(?:[0-9]{1,3}\.){3}[0-9]{1,3}$/', $_POST['ip'])) { $ip = $_POST['ip']; }?>