Future Proofing Changes to Validation of Username/Password Field in ZFCUser

I've been looking around at how to change the actual validation process of the registration fields in the ZFCUser module in Zend Framework 2.

There is a lot about extending and adding new fields etc. to the form but not validating these fields or extending the existing validation.

I have taken a look inside the code and found the RegistrationForm.php file and added my customer Regular Expression filters.

This works well and as expected but I am worried about this being over-written on any future upgrade.

How would I go about doing this so it is upgrade safe? Is it a case of extending a specific class or adding it as a local file in my custom modules as I have done with the view files.

I've same problem as you, and also do not find proper solution. But IMHO better way than change original source code is to override one of the ZfcUser services.

There is a service called 'zfcuser_change_password_form' defined in zfc-user Module.php. If you create own service with same name - the original one will be overriden. So, first you need to define your own filter / validator class (YourFilter), then in your Module.php add:

public function getServiceConfig()
{
    return array(
        // ...
        'factories' => array(
            // ... 
            'zfcuser_change_password_form' => function ($sm) {
                $options = $sm->get('zfcuser_module_options');
                $form = new \ZfcUser\Form\ChangePassword(
                       null, $sm->get('zfcuser_module_options')
                    );
                $form->setInputFilter(
                       new \YourModule\Form\YourFilter($options)
                    );
                return $form;
            },
        ),
    );
}

Such solution allows to update zfcuser without overriding your changes.