model unserialize for user group error - php

Question

I have a error on my model I am trying to work out I have unserialize($query->row('permission')) but for some reason I get a error.
Can not seem to work it out very strange to me. Not sure what to do or how to fix it.
A PHP Error was encountered
Severity: Warning
Message: unserialize() expects parameter 1 to be string, array given
Filename: user/users_group_model.php
Line Number: 16
Get User Group Model Function
public function getUserGroup($user_group_id) {
$query = $this->db->query("SELECT DISTINCT * FROM " . $this->db->dbprefix . "user_group WHERE user_group_id = '" . (int)$user_group_id . "'");
$user_group = array(
'name' => $query->row('name'),
'permission' => unserialize($query->row('permission'))
);
return $user_group;
}
Controller Function
public function getForm() {
$data['heading_title'] = $this->lang->line('heading_title');
$data['text_select_all'] = $this->lang->line('text_select_all');
$data['text_unselect_all'] = $this->lang->line('text_unselect_all');
$data['entry_name'] = $this->lang->line('entry_name');
$data['entry_access'] = $this->lang->line('entry_access');
$data['entry_modify'] = $this->lang->line('entry_modify');
$data['button_save'] = $this->lang->line('button_save');
$data['button_cancel'] = $this->lang->line('button_cancel');
$data['breadcrumbs'] = array();
$data['breadcrumbs'][] = array(
'text' => $this->lang->line('text_home'),
'href' => site_url('admin/dashboard')
);
$data['breadcrumbs'][] = array(
'text' => $this->lang->line('heading_title'),
'href' => site_url('admin/users_group')
);
$data['cancel'] = site_url('admin/users_group');
$user_group_id = $this->uri->segment(4);
$data['user_group_id'] = $user_group_id;
$user_group_info = $this->users_group_model->getUserGroup($user_group_id);
if (isset($this->request->post['name'])) {
$data['name'] = $this->request->post['name'];
} elseif (!empty($user_group_info)) {
$data['name'] = $user_group_info['name'];
} else {
$data['name'] = '';
}
$this->load->model('admin/user/users_group_model');
$ignore = array(
'blank',
'dashboard',
'column_left',
'menu',
'startup',
'login',
'logout',
'forgotten',
'reset',
'not_found',
'permission',
'footer',
'header'
);
$data['permissions'] = array();
$files = glob(APPPATH . 'modules/admin/' . 'controllers/*/*.php');
foreach ($files as $file) {
$part = explode('/', dirname($file));
$permission = basename($file, '.php');
if (!in_array($permission, $ignore)) {
$data['permissions'][] = $permission;
}
}
$this->load->library('request');
if (isset($this->request->post['permission']['access'])) {
$data['access'] = $this->request->post['permission']['access'];
} elseif (isset($user_group_info['permission']['access'])) {
$data['access'] = $user_group_info['permission']['access'];
} else {
$data['access'] = array();
}
$this->load->view('user/users_group_form', $data);
}

Answer 1

I have fixed the problem was had to add !empty post method above the name area and now working. It has removed all errors by doing it this way.
public function getForm() {
$this->load->model('admin/user/users_group_model');
$this->load->library('request');
$data['heading_title'] = $this->lang->line('heading_title');
$data['text_select_all'] = $this->lang->line('text_select_all');
$data['text_unselect_all'] = $this->lang->line('text_unselect_all');
$data['entry_name'] = $this->lang->line('entry_name');
$data['entry_access'] = $this->lang->line('entry_access');
$data['entry_modify'] = $this->lang->line('entry_modify');
$data['button_save'] = $this->lang->line('button_save');
$data['button_cancel'] = $this->lang->line('button_cancel');
$data['breadcrumbs'] = array();
$data['breadcrumbs'][] = array(
'text' => $this->lang->line('text_home'),
'href' => site_url('admin/dashboard')
);
$data['breadcrumbs'][] = array(
'text' => $this->lang->line('heading_title'),
'href' => site_url('admin/users_group')
);
$data['cancel'] = site_url('admin/users_group');
$user_group_id = $this->uri->segment(4);
$data['user_group_id'] = $user_group_id;
if (!empty($user_group_id) && $this->request->server['REQUEST_METHOD'] != 'POST') {
$user_group_info = $this->users_group_model->getUserGroup($user_group_id );
}
if (isset($this->request->post['name'])) {
$data['name'] = $this->request->post['name'];
} elseif (!empty($user_group_info)) {
$data['name'] = $user_group_info['name'];
} else {
$data['name'] = '';
}
$ignore = array(
'blank',
'dashboard',
'column_left',
'menu',
'startup',
'login',
'logout',
'forgotten',
'reset',
'not_found',
'permission',
'footer',
'header'
);
$data['permissions'] = array();
$files = glob(APPPATH . 'modules/admin/' . 'controllers/*/*.php');
foreach ($files as $file) {
$part = explode('/', dirname($file));
$permission = basename($file, '.php');
if (!in_array($permission, $ignore)) {
$data['permissions'][] = $permission;
}
}
if (isset($this->request->post['permission']['access'])) {
$data['access'] = $this->request->post['permission']['access'];
} elseif (isset($user_group_info['permission']['access'])) {
$data['access'] = $user_group_info['permission']['access'];
} else {
$data['access'] = array();
}
$this->load->view('user/users_group_form', $data);
}