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+--- Thread: Why my session is not working with error message-Cannot modify header information (/showthread.php?tid=19691)
Why my session is not working with error message-Cannot modify header information - El Forum - 06-16-2009
[eluser]manojchakri[/eluser]
Hi all.
Now I wrote a login validation form with database checking.Now after successfully logging in for the user I want to create session variable and get the user data from the session information. But When I am creating session it is giving error like "Cannot modify Header Information".My code is like this.
Controller:
Code:
class Form extends Controller
{
function Form()
{
parent::Controller();
$this->load->library('session');
}
function index()
{
//$this->load->view('header');
echo $this->session->userdata('user_name');
$this->load->view('simple');
$this->load->view('signup');
}
function post_form()
{
$username = $this->input->post('username');
echo $username;
$pwd=$this->input->post('pwd');
$this->load->model('simpl');
if($this->simpl->test1($username,$pwd)===TRUE)
{
$user=array('user_name'=>$username,'logged_in'=>TRUE);
$this->session->set_userdata($user);
echo $this->session->userdata('user_name');
echo '<BR>successfully logged in<a >Back to Home Page</a>';
}
}But when session is setting user data then the error like this is coming
Quote:A PHP Error was encounteredWhat should I do? I need to display the logged in user name like "welcome <user>" on every page and a logout link which should close the session and display "welcome guest" on every page and login link.Please help me with some sample code..Thanks in advance.
Severity: Warning
Message: Cannot modify header information - headers already sent by (output started at C:\xampp\htdocs\CodeIgniter_1.7.1\system\application\controllers\form.php:72)
Filename: libraries/Session.php
Line Number: 662
Why my session is not working with error message-Cannot modify header information - El Forum - 06-16-2009
[eluser]Dam1an[/eluser]
This comes up all the time (search anyone?)
It's cause because you prematurely sent some output to the screen, this can be anything, from a string, to a whitespace (eg if you have a newline before the opening PHP tags or after the closing tag)
Why my session is not working with error message-Cannot modify header information - El Forum - 06-16-2009
[eluser]manojchakri[/eluser]
Ok I got it.Thank you.But How do you know some session data is already set in Codeigniter.Is there any thing like isset() here??
Why my session is not working with error message-Cannot modify header information - El Forum - 06-16-2009
[eluser]Dam1an[/eluser]
If you use CI sessions, it will return false if you try to get something which hasn't been set, so you can do something like
Code:
if($this->session->userdata('logged_in')) {
echo 'Welcome ', $this->session->userdata('user_name');
} else {
echo 'Welcome guest';
}(You could also rewrite this using a ternary operator if you prefer)