CodeIgniter - 单击后退按钮后退出后仍可访问该成员的页面

Question

I am using CodeIgniter.

After I logon to the member's and click logout, I could still view the member's page when I click the BACK button.

Question Does anyone know so that if the user has logged out, it could not access the Member's page even clicking of BACK button?

Please see my code below..

Thanks..

    class Site extends CI_Controller{

    function index()
    {   
        if(!isset($this->session->userdata['is_loggged_in'])) 
            $this->login(); 
        else 
            $this->_template();      
    }

    function login()
    { 
        $data['main_content'] = 'login_form';
        $data['page_title']   = 'Login - php';
        $this->load->view('include/template' , $data);  
    }

    function validate()
    {  
        $this->load->library('form_validation'); 
        $this->form_validation->set_rules('username' , 'Username' , 'trim|required' );
        $this->form_validation->set_rules('password' , 'Password' , 'trim|required' ); 

        if($this->form_validation->run() == FALSE)
        {
            $this->login();
        } 
        else
        { 
            $this->load->model('member_model' , 'member');
            $query = $this->member->checklogin(); 

            //login successful , make sure no duplicate entry during registration
            if($query->num_rows() == 1)
            {
                $data = array(
                    'is_loggged_in' => TRUE ,
                    'username'      => $this->input->post('username'), 
                );
                $this->session->set_userdata($data);
                $this->_template();
            }
            else
            { 
                $data = array(
                        'main_content' => 'login_form' ,
                        'page_title'   => 'Error login' ,
                        'page_error'   => 'Invalid Username or password. '

                );
                $this->load->view('include/template' , $data); 
            }

        }
    }

    function _template()
    { 
        $data = array(
            'main_content' => 'include/default_inc',
            'page_title'   => 'Welcome home ran'
        ); 

        $this->load->view('include/template' , $data);  
    }

    function logout()
    { 
        $this->session->sess_destroy();
        redirect('site/login');
        exit;
    }
  }

/* end of controller site */

Answer 1

instead of checking session in index function try checking it in constructor

function __constuctor()
{   
    parent::__construct();
    $session = $this->session->userdata('is_loggged_in');
    if ( !$session) {
        $this->login(); 
    }else{
        $this->_template();    
    }     
}