zf2 Checkbox rendering by formInput fails - php

Question

I want to make a chekbox for terms of use. I've found an interesting solution, given by a webcoder How to validate a checkbox in ZF2
The case is that I have a difficult HTML structure, that's why I can't use neither formRow, nor formCollection to render. I'm trying to use the following approach instead:
$agreement = $form->get('agreement');
echo $this->formInput($agreement);
echo $this->formElementErrors($agreement);
And I receive the empty value:
<input type="checkbox" name="agreement" class="checkbox" value="">
I also tried to add hidden field, but my attempt also failed:
$agreement = $form->get('agreement');
echo $this->formHidden($agreement);
echo $this->formInput($agreement);
echo $this->formElementErrors($agreement);
The html is:
<input type="hidden" name="agreement" class="checkbox" value="">
<input type="checkbox" name="agreement" class="checkbox" value="">
As a result I receive errors about "Value is required and can't be empty"
May be someone can give me a tip how to properly render checkbox in my case?
code of my inputFilter:
<?php
namespace Auth\Form;
use Zend\InputFilter\InputFilter;
use Zend\Validator\Digits;
class UserFormFilter extends InputFilter {
public function __construct() {
$this->add(array(
'name' => 'agreement',
'validators' => array(
array(
'name' => 'Digits',
'break_chain_on_failure' => true,
'options' => array(
'messages' => array (
Digits::NOT_DIGITS => 'You must agree to the terms of use.',
)
),
),
),
));
}
}
?>

Answer 1

Check this out please.
$this->add(array(
'type' => 'Zend\Form\Element\Checkbox',
'name' => 'agreeterms',
'options' => array(
'label' => 'I agree to all terms and conditions',
'use_hidden_element' => true,
'checked_value' => 1,
'unchecked_value' => 'no'
),
'attributes' => array(//the difference is here
'value' => 'yes'
)
));
if you add the attributes array it should work.