Facebook CodeIgniter - can't log in on first attempt - php

Question

I'm using the Facebook PHP integration with CodeIgniter.
I have a problem where I click on the login link, it brings me to the Facebook login, I log in successfully, and when it redirects back to my page, none of the Facebook information has come through. Then if I click the login link again, it immediately logs me in without the need for the Facebook login form. If I were to refresh the page instead of clicking the login link the second time, the Facebook information still wouldn't show.
I feel that it's something to do with the session.
$facebook = $this->facebook;
$user = $facebook->getUser();
$user is always 0 until I click the login link for the second time.
This is the login flow:
I feel as if it's failing at the GET /oath/authorize phase.
public function fb_login() {
$facebook = $this->facebook;
// Get User ID
$user = $facebook->getUser();
$this->session->set_userdata(array('user' => $user));
var_dump($user);
$profile = null;
$logoutUrl = null;
$loginUrl = null;
try {
$profile = $facebook->api('/me');
$this->session->set_userdata(array('profile' => $profile));
} catch (FacebookApiException $e) {
error_log($e);
$user = null;
}
if ($user) {
$url = $this->uri->uri_string();
$url = str_replace('/', '-', $url);
$logoutUrl = $facebook->getLogoutUrl(array(
'next' => site_url('[omitted]/fb_logout'.'/'.$url)));
$this->session->set_userdata(array('logoutUrl' => $logoutUrl));
} else {
$loginUrl = $facebook->getLoginUrl(array('display' => 'touch'));
$this->session->set_userdata(array('loginUrl' => $loginUrl));
}
$facebook_array = array(
'user' => $user,
'profile' => $profile,
'logoutUrl' => $logoutUrl,
'loginUrl' => $loginUrl
);
return $facebook_array;
}
public function view_events($organiser_type) {
$this->load->helper('form');
$organiser_type = urldecode($organiser_type);
$data['organiser_type'] = $organiser_type;
$data['title'] = $organiser_type.' Events';
$data['events'] = $this->trinity_impulse_model->get_events_by_type(
$organiser_type,
array('event_start_date', 'event_start_time'),
array('asc', 'asc'));
$i = 0;
foreach ($data['events'] as $event) {
$data['events'][$i]['event_start_date'] = format_timestamp_to('dateFromDB', $event['event_start_date']);
$data['events'][$i]['event_end_date'] = format_timestamp_to('dateFromDB', $event['event_end_date']);
$data['events'][$i]['event_start_date'] = humanise_date($data['events'][$i]['event_start_date']);
$data['events'][$i]['event_end_date'] = humanise_date($data['events'][$i]['event_end_date']);
$data['events'][$i]['event_start_time'] = format_timestamp_to('shorttime', $event['event_start_time']);
$data['events'][$i++]['event_end_time'] = format_timestamp_to('shorttime', $event['event_end_time']);
}
$facebook_array = $this->fb_login();
var_dump($this->session->userdata('user'));
// Get session values.
/*$data['user'] = $this->session->userdata('user');
$data['profile'] = $this->session->userdata('profile');
$data['loginUrl'] = $this->session->userdata('loginUrl');
$data['logoutUrl'] = $this->session->userdata('logoutUrl');
*/
$data['user'] = $facebook_array['user'];
$data['profile'] = $facebook_array['profile'];
$data['loginUrl'] = $facebook_array['loginUrl'];
$data['logoutUrl'] = $facebook_array['logoutUrl'];
$this->load->view('[omitted]/view_events', $data);
}
EDIT: The other pages in my application work as normal. The login displays Facebook data on first attempt. There is nothing different in the other pages. They all use the fb_login() function in the same manner.
EDIT2: I did var_dump($facebook) to see what was different about the variable on the failed login. I found that the state is set when I encounter the problem. If it is not set, it logs in with no problem. I still don't know how to resolve that though. Here is the var_dump():
["state":protected]=> string(32) "ac816d6fa8fba908b6bd01f3e7f0ec75"

Answer 1

I have resolved this.
I don't know what the cause of the problem was, but I modified the code and now it works. The offending piece of code was:
try {
$profile = $facebook->api('/me');
} catch (FacebookApiException $e) {
error_log($e);
$user = null;
}
I wrapped an if around it so that it was only called if the $user variable was instantiated. Code is like so:
if ($user) {
try {
$profile = $facebook->api('/me');
} catch (FacebookApiException $e) {
error_log($e);
$user = null;
}
}