CakePHP : call controllers functions in external php files - php

Question

This is my situation:
1) a simple_php.php file in webroot folder
2) the users_controller.php in the app/controllers
3) the follow function in the users_controller.php :
function login_flat($user_id){
$user_data = $this->User->find('first', array(
'conditions' => array('User.id'=>$user_id)));
if($this->Auth->login($user_data)){
$this->Cookie->write('User.id', $this->Auth->user('id'), true, '+2 hour');
$this->Session->setFlash(__('Welcome back !', true));
$this->redirect(array('controller'=>'posts', 'action'=>'index'));
exit();
}
else{
echo 'ERROR!!';
exit();
}
}
(a simple function to login user. NOTE : I know it's not safe , but it's for test only)
Now, If I call via browser the function ( eg. www.mysite.com/users/login_flat/13 ) it WORKS ! but ... I need to call it via an other file, the simple_php.php located in the webroot of my domain.
I try with the php "header" function. It "call" (redirect) to the login_flat function , but the login not work !!! :(
Have any suggestion ? thx in advance.
P.S.
I'm using cakephp 1.2.6
------------- EDIT ------------------
I solve my trouble reading this:--> Solution

Answer 1

From the OP:
this is the code I uses for the redirect in the simple_php file :
header("Location:http://".$subdomain_locale.".".$site_subdomain.".com/users/login_via_app/".$user‌​_id."");
Which will redirect to
/users/login_via_app/13
Which is the wrong url, as it should be redirecting to
/users/login_flat/13
Also be sure to put 'exit();' after sending the header and check that nothing else is output before that, otherwise your redirect won't work
And, please check if the $sudomain_locale and $site_subdomain variables contains the right value, or debug the whole URL using this, instead of performing the redirect;
echo "this is the URL that will be redirected to:<br>";
print_r("Location:http://".$subdomain_locale.".".$site_subdomain.".com/users/login_via_app/".$user‌​_id."");
exit();