How to add class to fieldset? - zend-framework2

Question

I have a form in ZF2 with the following element being added:
$this->add(array(
'name' => 'animals',
'type' => 'radio',
'attributes' => array(
'id' => 'animals',
'class' => 'form-control',
),
'options' => array(
'label' => 'Favourite animal',
'options' => array(
'cat' => 'Cat',
'dog' => 'Dog',
'fish' => 'Fish',
),
),
));
And in my view script I have the folloing line:
<?php echo $this->formrow($form->get('animals')); ?>
Which is generating the following html:
<fieldset>
<legend>Favourite Animal</legend>
<label><input type="radio" name="animals" id="animals" class="form-control input-error" value="cat">Cat</label>
<label><input type="radio" name="animals" class="form-control input-error" value="dog">Dog</label>
<label><input type="radio" name="animals" class="form-control input-error" value="fish">Fish</label>
</fieldset>
How do I add a class to the fieldset?
I have tried adding the following to the options array, the attributes array, and as an option to the main array but it is not adding the class to the fieldset:
'fieldset_attributes' => array(
'class' => 'form-group',
),
[edit]
Looking into the code (\Zend\Form\View\Helper\FormRow::render) I've found this:
...
// Multicheckbox elements have to be handled differently as the HTML standard does not allow nested
// labels. The semantic way is to group them inside a fieldset
if ($type === 'multi_checkbox' || $type === 'radio' || $element instanceof MonthSelect ) {
$markup = sprintf('<fieldset><legend>%s</legend>%s</fieldset>', $label, $elementString);
}
...
Which means the only way to add a class to the fieldset (or legend if you wanted) is to extend the view helper.

Answer 1

I followed the answer as posted here (https://stackoverflow.com/a/27273068/351785).
From the answer (modified to suit my requirements):
Create the Application\Form\View\Helper\FormRow.php helper class like
below:
<?php
/**
* Extend zend form view helper formrow to allow class to be added to fieldset / legend
*/
namespace Application\Form\View\Helper;
use Zend\Form\View\Helper\FormRow as ZendFormRow;
class FormRow extends ZendFormRow
{
/**
* Utility form helper that renders a label (if it exists), an element and errors
*
* #param ElementInterface $element
* #throws \Zend\Form\Exception\DomainException
* #return string
*/
public function render(\Zend\Form\ElementInterface $element)
{
//... other code here
// Multicheckbox elements have to be handled differently as the HTML standard does not allow nested
// labels. The semantic way is to group them inside a fieldset
if ($type === 'multi_checkbox'
|| $type === 'radio'
|| $element instanceof MonthSelect
) {
$fieldset_class = $legend_class = '';
if($class = $element->getOption('fieldset_class')) {
$fieldset_class = sprintf(' class="%s"', $class);
}
if($class = $element->getOption('legend_class')) {
$legend_class = sprintf(' class="%s"', $class);
}
$markup = sprintf(
'<fieldset%s><legend%s>%s</legend>%s</fieldset>',
$fieldset_class,
$legend_class,
$label,
$elementString);
}
//... other code here
return $markup;
}
}
And override the factory in the onBootstrap() method of the Module.php
file like below:
namespace Application;
use Zend\Mvc\MvcEvent;
use Zend\View\HelperPluginManager;
class Module
{
/**
* On bootstrap for application module.
*
* #param MvcEvent $event
* #return void
*/
public function onBootstrap(MvcEvent $event)
{
$services = $event->getApplication()->getServiceManager();
// The magic happens here
$services->get('ViewHelperManager')->setFactory('formrow', function (HelperPluginManager $manager) {
return new \Application\Form\View\Helper\FormRow();
});
}
}
And add the classes as such:
$this->add(array(
'name' => 'animals',
'type' => 'radio',
'attributes' => array(
'id' => 'animals',
'class' => 'form-control',
),
'options' => array(
'label' => 'Favourite animal',
'fieldset_class' => 'form-group', //<== this
'legend_class' => 'form-legend', //<== and this
'options' => array(
'cat' => 'Cat',
'dog' => 'Dog',
'fish' => 'Fish',
),
),
));