Re: [development] Any reason why having a javascript timer fire every 2.5 second for an ajax request to my own callback(listed below) that all it does is return the contents of 2 _session variables would take up so much resources?

6 Feb 2011

      Drupal's bootstrap takes something like 50% of the total page
processing time on a typical page. You are still paying for that
overhead even though you don't need it.

See http://api.drupal.org/api/drupal/includes--bootstrap.inc/function/drupal_boo...
and look at something like the chatroom module's lightweight bootstrap
code:

http://drupalcode.org/viewvc/drupal/contributions/modules/chatroom/chatroomr...

In particular:

require_once './includes/bootstrap.inc';
drupal_bootstrap(DRUPAL_BOOTSTRAP_CONFIGURATION);
// Choose the minimum bootstrap level necessary for your module.

// Put your code here.
// See performance skyrocket.
// Rejoice.

Regards,
Greg

On Sun, Feb 6, 2011 at 10:15 AM, John Mitchell <mitchelljj98@gmail.com> wrote:
...
Any reason why having a javascript timer fire every 2.5 second for an ajax
request to my own callback(listed below) that all it does is return the
contents of 2 _session variables would take up so much resources?
John
function refreshcarttimer() {
    print($_SESSION['num_items'] . ',' .  $_SESSION['uc_price']);
    return;
}
/**
 * Implementation of hook_menu().
 */
function product_type_menu() {
  $items = array();
  $items['cart/refreshcarttimer'] = array(
    'title' => 'Refresh Shopping Cart',
    'description' => 'Refresh Shopping Cart',
    'page callback' => 'refreshcarttimer',
    'access callback' => TRUE,
    'type' => MENU_CALLBACK,
  );
  return $items;
}
On Sun, Feb 6, 2011 at 2:10 AM, John Mitchell <mitchelljj98@gmail.com>
wrote:
...
I have a javascript timer set to fire every 2.5 seconds so that I can set
the current values for the items and total for the shopping cart summary.  I
would like to be able to get these values from client side cookies or
javascript global variables so that I don't have to make an ajax call to the
server but I have found that the DOM elements are not accessible within the
javascript function unless I run an ajax request to a page (listed below)
and after it returns then the DOM elements are accessible (i.e.
$(".num-items").html(numItems);) and now I can update them.  Having these
ajax requests run every 2.5 seconds for every client will not scale.
How can I make Drupal DOM elements accessible within a javascript function
without having to do an ajax request to a page?
Thanks,
John
    setInterval('updateShoppingCartInfo()', 2500);
    function updateShoppingCartInfo(){
        var xmlHttpReq = new XMLHttpRequest();
        var url = 'https://' + document.domain + '/cart/refreshcarttimer';
        xmlHttpReq.open('post', url, true);
        xmlHttpReq.onreadystatechange = function() {
               if (xmlHttpReq.readyState != 4)  {
                   return;
               }
            else {
                var responseText = xmlHttpReq.responseText;
                                var numItems =
responseText.substr(0,responseText.indexOf(","));
                                var ucPrice =
responseText.substr(responseText.indexOf(",")+1);
                                $(".num-items").html(numItems);
                                $(".uc-price").html(ucPrice);
            }
        }
        xmlHttpReq.send(null);
    }
--
John J. Mitchell
--
John J. Mitchell
-- 
Greg Knaddison | 720-310-5623 | http://growingventuresolutions.com
http://masteringdrupal.com - Videos and Tutorials