无法在控制器内使用库函数

Question

I am trying to create my own library so i can handle custom areas in my application. i have a small library located at application/libraries which i called randomizer. it looks like this:

Class Randomizer { 
 public function __construct()
 {
   parent::_construct();
   $CI =& get_instance();
   $CI->load->library('session');
   $CI->load->database();
 }

 function test_function($name)
 {
    return 'Hi dear' . $name . 'welcome back!';
 }
}

In my Controller i tried to test out the simple test_function:

public function index()
{
    echo($this->Randomizer->test_function('John'));
    exit;
}

And I am getting the following error

Call to a member function test_function() on a non-object

Answer 1

There are couple of possible errors i can see. first you are not loading the library you created inside your controller. in case you don't use $this->load->library('randomizer'); right before you call the library funcion. if you are going to use the library all over the controller then load it via the controller __consturct. Also i guess you are not extending an existing Class so the parent::_construct() is not needed. make sure you understand why you are using a library and when you should use helpers. Read more about Codeigniter Libraries