PHP Access same class from a file included inside the class - php

Question

Here is the class:
functions.php
class buildPage {
public function Set($var,$val){
$this->set->$var = $val;
}
function Body(){
ob_start();
include('pages/'.$this->set->pageFile);
$page = ob_get_contents();
ob_end_clean();
return $page;
}
function Out(){
echo $this->Body();
}
}
So here is the main (index) page of the script.
index.php
include_once('include/functions.php');
$page = new buildPage();
$page->Set('pageTitle','Old Title');
$page->Set('pageFile','about.php');
$page->Out();
Now as you can see, it includes about.php file through class, actually inside the class.
And now, I want to access the same buildPage() class to change the page title.
about.php
<?php
$this->Set('pageTitle','New Title');
echo '<h1>About Us</h1>';
?>
But unfortunately, nothing happens.
Please be kind to take few minutes to give me some help!

Answer 1

OK. I've managed to fix the problem myself.
Changed function Body() and Out() as follows :
function Body(){
$pageFile = $this->Get('pageFile');
if(empty($pageFile)){
$pageFile = 'home.php';
}
$page_path = 'pages/'.$pageFile;
ob_start();
include($page_path);
if(!empty($page_set_arr) && is_array($page_set_arr)){
foreach($page_set_arr AS $k=>$v){
$this->Set($k,$v);
}
}
$page = ob_get_clean();
return $page;
}
function Out(){
$body = $this->Body();
echo $this->Header();
echo $body;
echo $this->Footer();
}
And then changed the file about.php as follows :
<?php
$page_set_arr = array(
'pageTitle' => 'About Us'
);
?>
<h1>About Us</h1>