Get loop text values from mform - moodle

Question

Mmform has a 'count' textfield. When user has filled with value 3, mform should create 'Unit part' by looping the textfields
(forename, designation and filemanager). Upon mform submission, I need to display Unit part filled by the user.
Could you let me know suggestions.
<?php
require('config.php');
require_once($CFG->libdir.'/formslib.php');
class active_form extends moodleform {
function definition() {
$mform = $this->_form;
$fileoptions = $this->_customdata['fileoptions'];
$count = $mform->addElement('text', 'count', get_string('count', 'form'), array('name' => 'count[]');
$count = $mform->setType('count', PARAM_INT);
for ($i=1; $i<=$count; $i++) {
// Unit
$mform->addElement('text', 'forename', get_string('forename', 'form'), array('name'=>'forename[]'));
$mform->setType('forename', PARAM_RAW);
$mform->addElement('text', 'designation', get_string('designation', 'form'), array('name'=>'designation[]'));
$mform->setType('designation', PARAM_RAW);
$mform->addElement('filemanager', 'attachment', get_string('attachment', 'form'), null, $fileoptions);
$mform->setType('attachment', PARAM_RAW);
}
$this->add_action_buttons();
}
function validation($data, $files) {
$errors = parent::validation($data, $files);
return $errors;
}
}
$mform = new active_form(null, $customdata);
if ($mform->is_submitted()) {
$data = $mform->get_data();
for ($i=1; $i <= $data->count; $i++) {
$forename = $data->forename;
$designation = $data->designation;
$attachment = $data->attachment;
echo 'forename' . $forename. '<br>';
echo 'designation' . $designation. '<br>';
echo 'attachment' . $attachment. '<br>';
}
}
echo $OUTPUT->header();
$mform->display();
echo $OUTPUT->footer();
?>
ex: User has filled with
count: 3
forename = SVs Group
designation = Assistant Engineer
attachment = 676208496
forename = Prime Group
designation = Staff Member
attachment = 646759033
forename = Ecos Group
designation = Staff Member
attachment = 107025147
Output:
count:3
forename: SVs Group
designation: Assistant Engineer
attachment: 676208496
forename: Prime Group
designation: Staff Member
attachment: 646759033
forename: Ecos Group
designation: Staff Member
attachment: 107025147