If file exists

[eluser]razerone[/eluser]
Hi.

I am trying to find the best place to start.

I would like to learn how to create a theme based template engine. and at the end of each controller file I create it shows up with something like

Code:

if (file_exists(DIR_TEMPLATE . $this->config->get('config_template') . '/template/common/header.tpl')) {
   $this->template = $this->config->get('config_template') . '/template/common/header.tpl';
  } else {
   $this->template = 'default/template/common/header.tpl';
  }
  
     $this->render();

Not sure where to start because I am trying to create a template system where has a theme folder.