auto refresh ajax div running on php page

Question

Please see my code below. I want to auto refresh a div on a php page. I tried to refresh through javascript and html header, but it is slowly slowing down my computer.

page2.php

<?php

if($_GET['type']!='ajax'){
    include 'header.php';
    echo "<div id='main-content'>";
}
?>
Itm 1</br>
Itm 2

<img class="ajax-loader" src="ajax-loader.gif" alt="loading..." />

<?php
if($_GET['type']!='ajax'){
    echo "</div>";
    include 'footer.php';
}?>

app.js

$.cergis = $.cergis || {};
$.cergis.loadContent = function () {
    $('.ajax-loader').show();
     $.ajax({
         url: pageUrl + '?type=ajax',
        success: function (data) {
            $('#main-content').html(data);
            // hide ajax loader
            $('.ajax-loader').hide();

  }
    });
    if (pageUrl != window.location) {
        window.history.pushState({ path: pageUrl }, '', pageUrl);
    }
}
$.cergis.backForwardButtons = function () {
    $(window).on('popstate', function () {
        $.ajax({
            url: location.pathname + '?type=ajax',
            success: function (data) {
                $('#main-content').html(data);
            }
        });
    });
}
$("a").on('click', function (e) {
    pageUrl = $(this).attr('href');
    $.cergis.loadContent();
    e.preventDefault();
});
$.cergis.backForwardButtons();

i have tried different variation but no luck. please help me.

thanks.

app.js changed...

function myTimer() {
  $('.ajax-loader').show();
  $.ajax({
      url: pageUrl + '?type=ajax',
      success: function (data) {
          $('#main-content').html(data);
          // hide ajax loader
          $('.ajax-loader').hide();
        }
  });

}

setInterval(function(){myTimer()}, 1000);

Answer 1

Try setTimeout:

function myTimer() {
  $('.ajax-loader').show();
  $.ajax({
      url: pageUrl + '?type=ajax',
      success: function (data) {
          $('#main-content').html(data);
          // hide ajax loader
          $('.ajax-loader').hide();
          setTimeout(myTimer,1000);//so that the request ends setTimeout calls a new request.
      },
      error: function () {
          setTimeout(myTimer,1000);//If there is an error in the request the "autoupdate" can continue.
      }
  });
}
myTimer();//fire

this way setTimeout() waiting to finish the request to invoke a new request.

setInterval() does not wait, which makes simuntaneos generate multiple events, which causes the slowness.

Answer 2

You can use setTimeout($.cergis.loadContent, 1000); to refresh once or setInterval($.cergis.loadContent, 1000); to refresh each seconds (1000 milliseconds = 1second).

See http://www.w3schools.com/js/js_timing.asp