Question

Trivial, but I swear I cannot find the information anywhere.

<?php $username = $this->form->username ?>
<?php echo $username->renderViewHelper() ?>

What does renderViewHelper() do here?

Answer 1

at times, you may want to use Zend_Form with the existing markup in the view, for example consider the below markup that is to be found in view file.

<form method="<?php echo $form->getMethod() ?>" action="<?php echo $form->getAction()?>">
    <div id="elements">
        <?php echo $form->element1->renderLabel() . $form->element1->renderViewHelper() ?>
        <?php echo $form->element2->renderLabel() . $form->element2->renderViewHelper() ?>
    </div>
</form>

the below syntax

$form->element1->renderLabel()

will fetch only the label tag. no fancy wrapper tags or anything. the same goes to

$form->element1->renderViewHelper()

this will only fetch the input (or whatever specified) element tag. so that you can embed the form with your own existing markup instead of allowing zend_form to create markup by itself.

check this link for more information http://framework.zend.com/manual/en/learning.form.decorators.individual.html

hope this helps you.