Get flatten Zend_Form error messages

Form.php

<?php
class My_Form extends \Zend_Form
{
    /**
     * Flatten Zend_Form error messages
     * 
     * @param \Zend_Form|null $form
     * @param array|null $messages
     * @param int $i
     * @return array 
     */
    public function getMessagesSimple(\Zend_Form $form = null, array $messages = null, &$i = 0)
    {
        $return = array();
        
        if (is_null($form)) {
            $form = $this;
            $messages = parent::getMessages();
        }
        
        foreach ($messages as $fieldname => $errors) {
            $subForm = $form->getSubForm($fieldname);
            
            if ($subForm instanceof \Zend_Form) {
                $return += $this->getMessagesSimple($subForm, $errors, $i);
                continue;
            }
            
            foreach ($errors as $name => $value) {
                $element = $form->getElement($fieldname);
                $label = $element->getLabel();
                $return[$i] = array(
                    'message'   => $value,
                    'label'     => $label,
                    'fieldname' => $fieldname);
                $i++;
            }
        }
        
        return $return;
}