Does a model require that you extend the base model class?

Code:

class Model {



    var $_parent_name = '';



    /**

     * Constructor

     *

     * @access public

     */

    function Model()

    {

        // If the magic __get() or __set() methods are used in a Model references can't be used.

        $this->_assign_libraries( (method_exists($this, '__get') OR method_exists($this, '__set')) ? FALSE : TRUE );

        

        // We don't want to assign the model object to itself when using the

        // assign_libraries function below so we'll grab the name of the model parent

        $this->_parent_name = ucfirst(get_class($this));

        

        log_message('debug', "Model Class Initialized");

    }



    /**

     * Assign Libraries

     *

     * Creates local references to all currently instantiated objects

     * so that any syntax that can be legally used in a controller

     * can be used within models.  

     *

     * @access private

     */    

    function _assign_libraries($use_reference = TRUE)

    {

        $CI =& get_instance();                

        foreach (array_keys(get_object_vars($CI)) as $key)

        {

            if ( ! isset($this->$key) AND $key != $this->_parent_name)

            {            

                // In some cases using references can cause

                // problems so we'll conditionally use them

                if ($use_reference == TRUE)

                {

                    // Needed to prevent reference errors with some configurations

                    $this->$key = '';

                    $this->$key =& $CI->$key;

                }

                else

                {

                    $this->$key = $CI->$key;

                }

            }

        }        

    }



}

Code:

class test extends Controller

{

    function test()

    {

        

    }

    

    function index()

    {

        echo 'test';

    }

    

    function test2()

    {

        echo $this->uri->segment(2); // you will get an error

    }

}