How to do mvc in codeigniter

Question

I've been using codeIgniter for 5 months now and I want to improve the way I write my code. Here's a method from a controller for users:

function create_user(){ 

         $user_data = array(
            'username' => 'Username', 'firstname' => 'Firstname',
            'middlename' => 'Middlename', 'lastname' => 'Lastname',
            'password' => 'Password', 'department' => 'Department', 
            'role' => 'Role'
        );

        foreach ($user_data as $key => $value) {
            $this->form_validation->set_rules($key, $value, 'required|trim');
        }

        if ($this->form_validation->run() == FALSE) {
            $departments = $this->user_model->list_departments();
            $it_roles = $this->user_model->list_roles(1);
            $tc_roles = $this->user_model->list_roles(2);
            $assessor_roles = $this->user_model->list_roles(3);

            $data['data'] = array('departments' => $departments, 'it_roles' => $it_roles, 'tc_roles' => $tc_roles, 'assessor_roles' => $assessor_roles);

            $data['content'] = 'admin/create_user';

            parent::error_alert();
            $this->load->view($this->_at, $data);

        } else {
            $username = $this->input->post('username');
            $salt = $this->bcrypt->getSalt();
            $hashed_password = $this->bcrypt->hash($this->input->post('password'), $salt);
            $fname = $this->input->post('firstname');
            $mname = $this->input->post('middlename');
            $lname = $this->input->post('lastname');
            $department = $this->input->post('department');
            $role = $this->input->post('role');

            $user_login     = array($username, $hashed_password, $salt);
            $user_profile   = array($fname, $mname, $lname);
            $this->user_model->register_user($user_login, $user_profile, $department, $role);

            $data['content'] = 'admin/view_user';

            parent::success_alert(4, 'User Sucessfully Registered!', 'You may now login using your account');


            $data['data'] = array('username' => $username, 'fname' => $fname, 'mname' => $mname, 'lname' => $lname, 'department' => $department, 'role' => $role);
            $this->load->view($this->_at, $data);
        }

    }

I basically cram in fetching of input, input validation, rendering views for errors or success, and other stuff in a single controller. What's the better way of doing this, how do you suggest I breakdown this function. Someone said that I should add a router/dispatcher between the view and the controller to handle POST, GET, COOKIE and SESSION but I don't have any idea how to do that.

Any code samples, suggestions that would help me grasp the proper way of doing things will be accepted as an answer.

Answer 1

I did some minor changes: Not setting unnecessary variables, grouping the userdata in an array etc. That's just the way I would do it. Other than that you're good on your way, I'd say.

<?php 
function create_user()
{ 
     $user_data = array ('username' => 'Username', 'firstname' => 'Firstname', 'middlename' => 'Middlename', 'lastname' => 'Lastname', 'password' => 'Password', 'department' => 'Department', 'role' => 'Role');

    foreach ($user_data as $key => $value) {
        $this->form_validation->set_rules($key, $value, 'required|trim');
    }

    if ($this->form_validation->run() == FALSE)
    {

        $data['data'] = array(  'departments'   => $this->user_model->list_departments(), 
                                'it_roles'      => $this->user_model->list_roles(1), 
                                'tc_roles'      => $this->user_model->list_roles(2), 
                                'assessor_roles'=> this->user_model->list_roles(3)
                        );

        $data['content'] = 'admin/create_user';

        parent::error_alert();
        $this->load->view($this->_at, $data);

    } 
    else 
    {
        $salt    = $this->bcrypt->getSalt();

        $user['username']       = $this->input->post('username');
        $user['hashed_password']= $this->bcrypt->hash($this->input->post('password'), $salt);
        $user['fname']          = $this->input->post('firstname');
        $user['mname']          = $this->input->post('middlename');
        $user['lname']          = $this->input->post('lastname');
        $user['department']     = $this->input->post('department');
        $user['role']           = $this->input->post('role');

        $user_login     = array($user['username'], $user['hashed_password'], $salt);
        $user_profile   = array($user['fname'], $user['mname'], $user['lname']);
        $this->user_model->register_user($user_login, $user_profile, $department, $role);

        $data['content'] = 'admin/view_user';

        parent::success_alert(4, 'User Sucessfully Registered!', 'You may now login using your account');

        unset($user['hashed_password']); // Just to be sure 
        $this->load->view($this->_at, $user);
    }

}

Answer 2

You'll also want to use redirection after a POST request so that you don't get duplicate submits.

function create_user() {

    $params = $this->input->post();

    if( !$this->user_model->valid_user_params( $params, $errors ) )
    {
        //Place errors in flash data
        //redirect and exit
    }

    if( !$this->user_model->register_user($params, $errors) )
    {
        //Place errors in flash data
        //redirect and exit
    }

    //redirect and exit

}

function created_user() {
    //read flash data
    //show some views with the errors or success message
}