CodeIgniter Hooks to display content on all pages - php

Question

I have a sidebar displayed on all my websites pages the same content should be displayed each time:
current cash
username
more info...
For the username I'm using the session within the regular controllers so that's alright but for the cash, I need to make a call to the database. I've tried to use hooks but I can't figure out how to display the info in the view (the variable is undefined).
I'm stuck when loading the session.
I get the message: Unable to locate the specified class: Session.php eventhough my session library is autoloaded and I added it one more time in the hook, just in case...
autoload.php
$autoload['libraries'] = array('database','session','form_validation','pagination', 'template');
My hooks.php
$hook['post_controller_constructor'] = array(
'class' => 'get_info_general',
'function' => 'get_info_general',
'filename' => 'get_info_general.php',
'filepath' => 'hooks',
'params' => ''
);
My get_info_general.php
class get_info_general extends CI_Controller{
private $CI;
public function __construct() {
parent::__construct();
$this->load->helper('url');
$this->load->library('session');
$this->load->library('database');
}
function get_info_general(){
$this->load->model('usersModel');
$cash = $this->usersModel->check_cash_player();
$data['cash'] = $cash;
} }
In UsersModel:
public function check_cash_player(){
$currentUserID = $this->usersModel->get_user_id();
$query = $this->db
->select('cash')
->from('place')
->where('id_player', $currentUserID)
->get();
return $query->row('cash');
}
UPDATE:
After #alexander popov suggestion I changed the code to:
class get_info_general {
private $CI;
public function __construct() {
$CI =& get_instance();
$CI->load->helper('url');
$CI->load->library('session');
}
function get_info_general(){
$this->load->model('usersModel');
$cash = $this->usersModel->check_cash_player();
$data['cash'] = $cash;
} }
And I get: Undefined property: get_info_general::$load
UPDATE 2:
Using the code provided here I don't get any error message and my page is displayed. However $cash is still undefined in my page. Adding the following code to get_info_general.php doesn't help:
$data['cash'] = $cash;
$data['main_content'] = 'loginForm';
$this->load->view('templates/default',$data);