Question

I have two files php(index.php & data.php), the first send data to the second, and this it runs every one second and show the data.
The problem is the data is not updating

Maybe the code explains better

data.php

  <?php
  session_start();

  $xml = simplexml_load_file("file.xml"); // the contents of the file changes every second
  $json = json_encode($xml);
  $_SESSION['varname'] = $json;
  ?>

index.php

  <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.0/jquery.min.js"></script>
    <script language="JavaScript">
          window.setInterval(function() { 
        <?php 
        session_start(); 
        $json = $_SESSION['varname']; 
        ?>

        var newdata = <?php echo $json ; ?>;
    //code to show data

    }, 1000); 
          </script>

Thank you in advance

Answer 1

session_start must be called before any output (see notes in the documentation) which means you have to call session_start before any output:

<?php 
    session_start(); ?>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.0/jquery.min.js"></script>
<script language="JavaScript">
      window.setInterval(function() { 
    <?php 
    $json = $_SESSION['varname']; 
    ?>

    var newdata = <?php echo $json ; ?>;
//code to show data

}, 1000); 
      </script>