Q:

Facebook not able to scrap my url if session is set in codeigniter

I am using addthis for sharing and framework is Code Igniter.  
Problem is if in my controller i check session then facebook not able to scrap my url.If i remove session then it is working. So what can i do to working fb sharing with session.
The following code is working:
controller
public function index()
{
     $this->load->view('client/home');
}

if i check session then fb sharing is not working:
public function index()
{
    if(!$this->session->userdata('client_id'))
    {
        redirect('client/login/index', 'refresh');
        exit;
    }
     $this->load->view('client/home');
}

Thanks in advance.
sidenote:  i set session when customer login into website. so when customer click on FB sharing button the session is already set.

A:

Try this modified version of the code:
public function index()
{
    if(!$this->session->userdata('client_id') && !strstr( $_SERVER['HTTP_USER_AGENT'], 'facebookexternalhit') )
    {
        redirect('client/login/index', 'refresh');
        exit;
    }
     $this->load->view('client/home');
}

I've added an condition, which checks to see if the user agent is the Facebook scraper (facebookexternalhit). If the user-agent is not Faecebook, it forces login. (Remember that user-agent can be spoofed). If it detect Facebook, it will load the page and allow Facebook to scrape the content correctly.

