Understanding codeigniter base controller structure - codeigniter

Question

The following is a working example of how my Codeigniter website currently functions:
Model:
<?php
class Default_model extends CI_Model
{
function __construct()
{
// Call the Model constructor
parent::__construct();
}
function get_link()
{
$query = $this->db->query('SELECT * FROM links LIMIT 5');
return $query->result();
}
Controller:
<?php
class Home extends CI_Controller {
public function index()
{
$this->load->model('segment1/Page_model');
$data['link'] = $this->Page_model->get_link();
$this->load->view('page_view', $data);
}
}
View:
<h2>Link</h2>
<ul>
<?php if (isset($link)):?>
<?php foreach ($link as $row):?>
<li><?=$row->link?></li>
<?php endforeach;?>
<?php endif;?>
</ul>
I want to begin using a base controller for the above example, and while I've followed a few online examples - I can't quite get it right, and I'd appreciate some guidance...
I autoload the Model, no problem
The View file remains
I alter the config.php file
Controller:
<?php
class Home extends Main_Controller {
public function index()
{
$this->load->model('segment1/Page_model');
$this->load->view('page_view', $data);
}
}
MY_Controller
<?php
class MY_Controller extends CI_Controller
{
function __construct()
{
parent::__construct();
}
}
Now, here's where I get stuck - I can't quite figure out exactly what goes in the Main_Controller, and how it's structured...
Main_Controller:
<?php
class Main_Controller extends MY_Controller
{
function __construct()
{
parent::__construct();
//
// WHAT GOES IN HERE?
// SERIOUSLY, HELP!
//
}
}
Clearly, there's one big line of data missing from the original controller...
$data['link'] = $this->Page_model->get_link();
How does it all tie up?

Answer 1

Not exactly sure if I understand your question correctly, but if you want to avoid repeating this line:
$data['link'] = $this->Page_model->get_link();
What you can do is to put that in the constructor and create a public variable where you can store it.
i.e.
Main_Controller:
<?php
class Main_Controller extends MY_Controller
{
public $link;
function __construct()
{
parent::__construct();
$this->load->model('segment1/Page_model');
$this->link = $this->Page_model->get_link();
}
}
Controller:
<?php
class Home extends Main_Controller {
public function index()
{
$this->load->view('page_view', array('link' => $this->link));
}
public function another_page()
{
// you can keep using the value assigned to link in other
// methods without having to call Page_model->get_link() everytime
$this->load->view('page_view', array('link' => $this->link));
}
}