Redirect loop in full site to mobile site using session

Question

I have a full site that has been in OS-commerce and mobile site is in core PHP (codeignitor), and full version and a mobile version on sub-domain.

eg full site: www.example.com and mobile site domain is m.example.com . when user open full site domain in mobile, then website redirect proper mobile domain, But if mobile user want to view full site then user can view fullsite in mobile.

I have used this to complete the redirect http://code.google.com/p/php-mobile-detect/ , But it is not redirecting to the full site or to the mobile site using session. I know that I have to use PHP SESSIONS and REQUEST in order to get this to work but I am not sure how to use them in this instance, so could you please suggest how to solve this redirecting issue using session?

Here my code is:

session_start(); 

  include('includes/Mobile_Detect.php');
  $detect = new Mobile_Detect;

 if(isset($_REQUEST['fullsite']) && $_REQUEST['fullsite'] == 'yes')
 {//check if fullsite view request from mobile or website?

    $_SESSION['fullsite']="yes";

    if($detect->isMobile()) {
               $_SESSION['website']="mobile";
    }
    else{
       $_SESSION['website']="computer"; 
    }

    $deviceType = header('Location: https://www.example.com/');
  }
  else
  {
    if($_SESSION['website'] =="mobile"  && $_SESSION['fullsite'] !="yes")
    {
        if($detect->isTablet())
        {
            $deviceType = 'tablet';
        }
        else
        {
            $deviceType = 'phone';
        }

        $deviceType = header('Location: https://m.example.com/');
    }
    elseif($_SESSION['website'] =="computer" && $_SESSION['fullsite'] =="yes")
    {
        $deviceType = 'computer';
        $deviceType = header('Location: https://www.example.com/');
    }
    else{   
        $deviceType = 'computer';
     }

    $scriptVersion = $detect->getScriptVersion();
    session_destroy();
  }

Answer 1

From what I could get from github page you should be able to make it work like this:

index.php

session_start();

if ($_GET['fullscreen'] == 'yes') {
    $_SESSION['fullscreen'] = 1;
} else if ($_GET['fullscreen'] == 'no') {
    $_SESSION['fullscreen'] = 0;
}

if (false == isset($_SESSION['fullscreen']) && ($_SESSION['fullscreen'] == 0)) {
    // If session['fullscreen'] has not been set (maybe first visit
    // or the user does not what in fullscree
    // check the device and do redirect
    require_once 'Mobile_Detect.php';
    $detect = new Mobile_Detect();


    // Any mobile device (phones or tablets).
    if ( $detect->isMobile() ) {

    }
    ...
}

// Other code here

When visiting from mobile, if the user wants the full version, provide an anchor to url with GET parameter fullscreen=yes ( http://example.com?fullscreen=yes ) If on full site and detect mobile (not included in code above), you could provide a link to mobile version with fullscreen=no