zf2, Form collections not creating correct input name in zf2

Question

I am trying create , html collection for colors input field .. which will dynamically added using javascript

My ColorFieldset code is

namespace Dashboard\Form;

use Zend\Form\Fieldset;
use Zend\InputFilter\InputFilterProviderInterface;

class ColorFieldset extends Fieldset implements InputFilterProviderInterface
{
    public function __construct()
    {

        parent::__construct('color');

        $this->add(array(
            'name' => 'hash',
            'options' => array(
                'label' => 'Color'
            ),
            'attributes' => array(
                'required' => 'required',
                'class'   => 'input-mini'
            )
        ));
    }

    /**
     * @return array
     \*/
    public function getInputFilterSpecification()
    {
        return array(
            'hash' => array(
                'required' => true,
            )
        );
    }
}

and added it into form

$this->add(array(
    'type' => 'Zend\Form\Element\Collection',
    'name' => 'colors',
    'options' => array(
        'count' => 2 ,
        'should_create_template' => true,
        'allow_add' => true,
        'target_element' => array(
            'type' => 'Dashboard\Form\ColorFieldset'
        )
    )
));

and in my view file .. colors.phtml

<div id="colors_container" class="">
     <?php  echo $this->formCollection( $form->get('colors')); ?>
</div>

it printing output like

<div class="" id="colors_container">

   <label><span>Color</span><input type="text" value="" class="input-mini" required="required" name="hash"></label>

   <label><span>Color</span><input type="text" value="" class="input-mini" required="required" name="hash"></label>

   <span data-template='<label><span>Color</span><input name="hash" required="required" class="input-mini" type="text" value=""></label>'></span>

</div>

It supposed to print like .. which explained in zf2 manual 2.0

<div class="" id="colors_container">

   <label><span>Color</span><input type="text" value="" class="input-mini" required="required" name="colors[0][hash]"></label>

   <label><span>Color</span><input type="text" value="" class="input-mini" required="required" name="colors[1][hash]"></label>

   <span data-template='<label><span>Color</span><input name="colors[__index__][hash]" required="required" class="input-mini" type="text" value=""></label>'></span>

</div>

I expected html input name as colors[__index__][hash] . But it printing name as <input type="text" value="" class="input-mini" required="required" name="hash"> .

In above case .I will only get one color name in post $_POST['hash'] .

why zf2 not print <input type="text" value="" class="input-mini" required="required" name="colors[0][hash]"> ? Please advice what is wrong in my code .

Answer 1

Ohh finally found answer by myself . I have to call

$form->prepare();

before rendering anything in the view . now it works