how to add form validation from controller in zend framework 2 - zend-framework2

Question

I tried to add a validation from my controller like below. but it always shows this
if ($request->getPost('ownerType') == "Company") {
$form->getInputFilter()->get('companyName')->getValidatorChain()->addValidator('required');
}
shows error. I confused with below error.
Catchable fatal error: Argument 1 passed to Zend\Validator\ValidatorChain::addValidator() must implement interface Zend\Validator\ValidatorInterface, string given, called in E:\xampp\htdocs\hossbrag\module\WebApp\src\WebApp\Controller\JobController.php on line 177 and defined in E:\xampp\htdocs\hossbrag\vendor\zendframework\zendframework\library\Zend\Validator\ValidatorChain.php on line 100
My controller is here
<?php
namespace WebApp\Controller;
use Zend\Mvc\Controller\AbstractActionController;
use Zend\View\Model\ViewModel;
use WebApp\Entity\User;
use Zend\View\Model\JsonModel;
use vendor\mpdf\mpdf;
class JobController extends AuthenticatedController
{
public function createAction()
{
$form = new \WebApp\Form\JobpostingForm();
$form->get('companyName')->setValueOptions($company);
$checkAgreement = true;
$request = $this->getRequest();
if ($request->getPost('ownerType') == "Company") {
$form->getInputFilter()->get('companyName')->getValidatorChain()->addValidator('required');
}
}
}
What should to change in my controller to get appropriate solution.

Answer 1

If you encounter such a clear error, simply check out the sources ;)
First one to check would be Zend\Validator\ValidatorInterface. The Error shows you, that a Class implementing this interface is excepted. Looking at the code you'll see, the function wants a Class, not just a string.
But since you're used to ZF a little it becomes clear that you know there's other ways to add stuff. So let's take a look at Zend\InputFilter\InputFilter#add(). You'll see that the first param of the add() function indeed asks for a class implementing ValidatorInterface. But it also accepts some other stuff:
/**
* Add an input to the input filter
*
* #param array|Traversable|InputInterface|InputFilterInterface $input
* #param null|string $name
* #return InputFilter
*/
public function add($input, $name = null)
{
//...
}
It also accepts array, Traversable, InputInterface and InputFilterInterface. So choices are there.
Now, i have never done this myself and i sincerely hope this works (if not i suck!), but assuming you're using the array-syntax, all you have to do is this:
[...]->getValidatorChain()->add(array(
'type' => 'Zend\Validator\NotEmpty'
));
Let me know if this worked out for you ;)