Does form processing code need to be abstracted? (Zend_Form)

Question

In Zend Frameworks tutorials, I can see form processing code like

if ($request->isPost()) {
            $formData = $request->getPost();

            $code = $request->getParam("code");
         $url = $request->getParam("url");

            if ($form->isValid($formData)) {
            // here goes code to determine insert/update action, 
            //retrive record data
            //and perform relative database operation

This code repeats for many forms. I am trying to make form handling better, yet not to over-engineer it. So far I have moved this code from Controllers into Form object. But the code still diplicates for different form types.

My question is this - Should I prefer to keep form handling code duplicate or write some ProcessSubmit() Zend_Form method that will be used by all subclasses? I had experience that abstraction is not always good and sometimes you end up synching two classes that shoul've been different from beginning.

ZF examples demonstrate duplicate code, so I wonder if this duplicity is justifed (at least for small 3-4 form sites) or needs to be avoided by all means.

P.S. This task seems to be pretty common, I wonder if I do double work and there is already a ZF class for CRUD specific form handling.

Answer 1

I think is over-enginering, it will be more trouble to redo the form class you're planning to create if you ever have a need in the future.

But it really depends if you have very similar forms, then you could justify building a module just to create the same one over and over again. If they're different even just for a pair of inputs i wouldn't do it, you'll lose flexibility just to save a few lines.

Answer 2

Perhaps an action helper could, well, help you out here:

class App_Controller_Action_Helper_ProcessFormSubmit extends Zend_Controller_Action_Helper_Abstract
{
    public function isValid(Zend_Form $form)
    {
        if ($this->getRequest()->isPost()) {
            return $form->isValid($this->getRequest()->getPost());
        } else {
            return false;
        }        
    }

    public function direct(Zend_Form $form)
    {
        return $this->isValid($form);
    }

}

This allows you to handle form submission processing like this:

// or: if ($this->_helper->processFormSubmit->isValid($form)) {
if ($this->_helper->processFormSubmit($form)) {
    // here goes code to determine insert/update action, 
    //retrive record data
    //and perform relative database operation
}

This can be extended to your needs, e.g. automatic error handling and so on...

Answer 3

What I have actually done was to move validation into the domain objects (or model layer), and then my domain layer implements a save() method.

While I don't use Zend_Form in my domain layer, I have noticed that others will implement a Zend_Form instance in their domain models so that they can present a consistent form everywhere for each domain model. Personally, I feel that this couples domain objects to the presentation layer too much.

Instead, I do use Zend_Filter_Input as the backbone for validation in my domain objects.

Answer 4

If you want to use "thin controllers/fat models" after validating the form just pass the whole form or form values to your model.

As for control structures in your controller they are "normal".