CodeIgniter sample code 01

<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');

class Index extends CI_Controller {

    function __construct()
    {
        global $data;
        parent::__construct();
        $this->check_admin_login();


    }


    function index()
    {
       global $data;
       $data['main_content']='index';
       $this->load->view('admin_template',$data);
    }

    function update_settings()
    {
        global $data;
        $this->load->library('form_validation');
        if(count($this->input->post('configuration'))>1){
            foreach ($this->input->post('configuration') as $key => $value)
            {
                $this->form_validation->set_rules('configuration['.$key.']', $key, 'required');
            }

        }


        if($this->form_validation->run()!=false)
        {
            //echo "form validated"; // now save into database
            $this->load->model('configuration_model');
            $data_saved=$this->configuration_model->update_configuration($_REQUEST);
            if($data_saved)
            {

                $data['msg']="Data Updated successfully";
                $data['configurations']=$this->configuration_model->get_all_configuration();
                /*$data['main_content']='index';
                $this->load->view('admin_template',$data);*/


            }
        }
        else
        {
            /*$data['main_content']='index';
            $this->load->view('admin_template',$data);*/
        }
        // load the default view :p
        $this->index();


    }


    function check_admin_login()
    {
        $is_logged_in = $this->session->userdata("ADMIN_LOGGED_IN");
        if(!isset($is_logged_in) || $is_logged_in != true)
        {
            //echo 'You don\'t have permission to access this page. <a href="login">Login</a>';
            redirect("login");
            die();
            //$this->load->view('login_form');
        }
    }
    function site_setting()
    {
       /*global $data;
       $data['main_content']='index';
       $this->load->view('admin_template',$data);*/
       $this->index();
    }
    function admin_setting()
    {
        global $data;
        $data['main_content']='admin_setting';
        $this->load->model("admin_model");
        $data['admin']=$this->admin_model->get_admin();
        //pr($data['admin']);
        $this->load->view('admin_template',$data);
    }
    function update_admin_setting()
    {
        global $data;
        $form_data = $this->input->post('admin');

        if($form_data)
        {

            $this->load->library('form_validation');

            $this->form_validation->set_rules('admin[first_name]', "First Name", 'required');
            $this->form_validation->set_rules('admin[last_name]', "Last Name", 'required');
            $this->form_validation->set_rules('admin[email]', "Email Address", 'required|email');
            $this->form_validation->set_rules('admin[username]', "Username", 'required');
            if($this->form_validation->run()!=false)
            {
                //echo "form validated"; // now save into database
                $this->load->model('admin_model');
                $data_saved=$this->admin_model->save($this->input->post('admin'));
                if($data_saved)
                {
                    $data['msg']="Data Updated successfully";
                }
                else
                {
                    $data['err']="Data not saved. something went wrong";
                }
            }

        }
        else
        {

        }
        $this->admin_setting();


    }
    function change_admin_password()
    {
        global $data;
        $form_data = $this->input->post('admin');

        if($form_data)
        {

            $this->load->library('form_validation');

            $this->form_validation->set_rules('oldpassword', "Old password", 'required');
            $this->form_validation->set_rules('newpassword', "New Password", 'required|min_length[6]|matches[confirmpassword]');
            $this->form_validation->set_rules('confirmpassword', "Confirm Password", 'required');
            if($this->form_validation->run()!=false)
            {
                //echo "form validated"; // now save into database
                $this->load->model('admin_model');
                $query=$this->db->from('admin')->where('id','1')->limit('1')->get();
                $admin_data=$query->row();

                if($admin_data->password!=md5($this->input->post('oldpassword')))
                    $err="Old password is wrong";
                if(!isset($err))
                {
                    $data_saved=$this->admin_model->change_password(md5($this->input->post('newpassword')));
                    if($data_saved)
                    {
                        $data['msg']="Password Updated successfully";
                    }
                    else
                    {
                        $data['err']="Data not saved. something went wrong";
                    }
                }else{
                    $data['err']=$err;
                }
            }
        }
        else
        {

        }

      $this->admin_setting();
    }
    function email_setting()
    {
       global $data;
       $data['main_content']='site_setting';
       $this->load->view('admin_template',$data);
    }
    function members_area()
    {
       $data['main_content']='userhome';
        $this->load->view('admin_template',$data);
    }

}

/* End of file site.php */
/* Location: ./application/controllers/site.php */