Question

I’m trying to access protected variables in a second-child class extended from its parent, but every time I try to access them, they are NULL.

What’s weird to me is that I can access the parent’s protected functions without a problem (eg. $this->_submit in the second child class.) I checked the parent class and the variable are set there, so I’m sure it’s something dumb I am missing (still learning OOP). Maybe something to do with the constructor? But if I call parent::__construct() in the second child, it throws an error because the config details are missing?

Parent

<?php defined('SYSPATH') or die('No direct script access.');
abstract class Rimage {

    protected $_config;
    protected $_service;
    protected $_client;

public static function instance($config, $service)
{
    return new Rimage_Client($config, $service);
}

public function __construct($config = array(), $service = NULL)
{
    $this->_config  = $config;
    $this->_service = $service;
    $this->_client = new SoapClient('url');
}

}
?>

First Child

<?php defined('SYSPATH') or die('No direct script access.');

class Rimage_Client extends Rimage {

    protected $_caller;

    public function __construct($config = array(), $service = NULL)
    {
        parent::__construct($config, $service);
        $this->_caller = Arr::get($config, 'caller', array());
    }

    public function get($id = NULL)
    {   
    return new Rimage_Job_Status($id);
    }

    protected function _submit($options, $request_class)
    {
        $job->request = $options;

        $response = $this->_client->$request_class($job); /** Client is undefined??**/
        return $response;   
    }

} // End Rimage_Client
?>

Second Child

<?php defined('SYSPATH') or die('No direct script access.');
class Rimage_Job_Status extends Rimage_Client {

    public function __construct($id) 
    {       
        return $this->_retrieve($id);
    }

    private function _retrieve($id = NULL)
    {
        $options->CallerId  = $this->_caller; /** $_caller is undefined??? **/
        $options->JobId     = $id;

        $response = $this->_submit($options, 'test');
        return $response->whatever;
    }

} // End Rimage_Job_Status
?>

Calling the code with Rimage::instance($config,'job')->get('12345');

Edit:

The error I’m getting is that $_client is NULL in the child, but not in the parent… $_caller is NULL in the second child.

Cheers and merry christmas!

Answer 1

The __construct() function is not inherited to subclasses, so there is no reason for $this->_caller to be set in the second child class. To execute the __construct function of the parent, you need to invoke parent::__construct() in the __constructor of the child.