Polymorphism/Resource loader with Zend - php

Question

I've never worked before with polymorphism. I just heard about it when this question came up.
I have a little backend with 2 permissions. Admin/Normal User. Depending on the permission, i want to display a different navigation, less or more options on the forms etc. But i don't want to create a form for each permission but rather disable the elements i don't need etc.
How would i go with that?
At the moment, i'm using something like that: (Which isn't really polymorphism)
<?php
class My_Resources_ResourceLoader extends Zend_Application_Resource_ResourceAbstract {
public $templateForm = null;
public $customerForm = null;
function init() {
$permission = 'admind';
if($permission == 'admin') {
$this->templateForm = new Application_Form_newTemplate;
} else {
$form = new Application_Form_newTemplate;
$form->removeElement('newTemplate_customer');
$this->templateForm = $form;
}
return $this;
}
}
And in my controller e.g.
<?php
$bootstrap = $this->getInvokeArg('bootstrap');
$xx = $bootstrap->getResource('ResourceLoader');
$this->view->test = $xx->templateForm;
The roles never gonna change. This will probably be okay but isn't the very best solution. What would be a better approach to this?

Answer 1

I've thrown away the approach above and now use real polymorphism like this:
at Application/Model got an interface like:
And 2 Classes like:
<?php
class Application_Model_TemplateUser implements Application_Model_TemplateInterface {
private $table = null;
private $row = null;
private $id = null;
private $formValues = null;
function __construct() {}
public function exist() {}
public function save() {}
public function getCustomerId($name) {}
public function update() {}
public function getForm() {
$form = new Application_Form_newTemplate;
$form->removeElement('newTemplate_customer');
return $form;
}
}
And
<?php
class Application_Model_TemplateAdmin implements Application_Model_TemplateInterface {
private $table = null;
private $row = null;
private $id = null;
private $formValues = null;
function __construct() {}
public function exist() {}
public function save() {}
public function getCustomerId($name) {}
public function update() {}
public function getForm() {
return new Application_Form_NewTemplate();
}
}
In my Controller i do:
<?php
$permission = 'User'; //TODO: Get from Session
$class = 'Application_Model_Template' . $permission;
$xx = new $class;
$form = $xx->getForm();
$this->view->test = $form;
This are just examples. But i think like that I'm really on a better way. Maybe i'm going to use abstract classes since i'm using Zend_Db-Table_Row, which is always the same for updating a row, so it would make more sense using a abstract class instead of an interface.
Nice article about Polymorphism in PHP: http://net.tutsplus.com/tutorials/php/understanding-and-applying-polymorphism-in-php/