How to log out from facebook in my site - php

Question

I'm using https://github.com/pocesar/facebook-kohana for facebook login. I have problem with facebook logout. It doesn't destroy facebook session. I've tried so many things and I've read many questions. I tried this in my logout method, but no result:
$this->redirect('https://www.facebook.com/logout.php?
next=mysite.dev
&access_token=USER_ACCESS_TOKEN');
My logout method is:
public function action_logout(){
$facebook = new Facebook(array(
'appId' => 'appId',
'secret' => 'mySecret',
));
$user = $facebook->getUser();
$facebook->destroySession();
Session::instance()->delete('user');
$this->redirect('/');
}
How to destroy session, so that user can log in my site with another facebook account? Thanks!
My method login is:
public function action_fbLogin(){
$facebook = new Facebook(array(
'appId' => 'appId',
'secret' => 'Secret',
));
$user = $facebook->getUser();
if ($user) {
$user_profile = $facebook->api('/me', array('fields' => 'id,email,name,first_name,last_name,picture'));
$user_id = Model_UserFunctions::checkIfUserExist($user_profile['email']);
if($user_id > 0)
{
Session::instance()->set('user', array(
'fb_id' => $user_profile['id'],
'user_id' => $user_id,
'pic' => $user_profile['picture'],
'email' => $user_profile['email'],
'first_name' => $user_profile['first_name'],
'last_name' => $user_profile['last_name'],
));
//var_dump($_SESSION);
$this->redirect('profile');
exit;
}
$values = array(
'email' => $user_profile['email'],
'username' => $user_profile['email'],
'password' => '12345678'
);
$user = ORM::factory ( 'User' );
$user->values($values);
try
{
if($user->save()){
$user_new_id = $user->as_array();
$user_new_id = $user_new_id['id'];
Session::instance()->set('user', array(
'fb_id' => $user_profile['id'],
'user_id' => $user_new_id,
'pic' => $user_profile['picture'],
'email' => $user_profile['email'],
'first_name' => $user_profile['first_name'],
'last_name' => $user_profile['last_name'],
));
$this->redirect('profile');
}
}
catch (ORM_Validation_Exception $e)
{
$result = $e->errors('models');
echo '<pre>';
print_r($result);
exit;
}
}
else
{
$this->redirect($facebook->getLoginUrl(array('id,email,name,first_name,last_name,picture')));
}
exit;
}
Edited: My goal to use Facebook logout is because in my site I only use Facebook login, there isn't another way to log in my site, that's idea of it. And I should have logout method in my site, so when user wants to logout, he could do it.
This logouts me from facebook but facebook login page is shown. How to redirect next to my site. I've set it as next but it doesn't redirect to it:
<a href="https://www.facebook.com/logout.php?
next=http://mysite.dev
&access_token=Null">Logout</a>

Answer 1

You can get facebook logout url using facebook-php-sdk API.
When user will click on that url he will be offline from his facebook account.
if ($user) {
$logoutUrl = $facebook->getLogoutUrl();
} else {
$loginUrl = $facebook->getLoginUrl();
}
For more info you can check this url.
https://github.com/facebookarchive/facebook-php-sdk

Answer 2

Then you don't have a problem with facebook
Is only the session that needs to be destroyed...
On this page of PHP manual there is an example showing you might need aditional steps to destroy a session beyond unset($_SESSION)
http://php.net/manual/en/function.session-destroy.php
Forcing the users to log off from Facebook does not seem a good move for me.
Millions of FB users have intentionally asked to stay logged in and if they visit your site and logoff from there they might think it wasn't very friendly of you to log them off the FB accounts. many don't even remember their pwd... so you would be creating a problem for them and they might never comeback to your site... Just saying