Hi,

I have the following extension

class GST extends Extension {

	private static $casting = array(
		'GST' => 'Currency'
	);

	public function GST(){
		parent::__construct();
		$config = SiteConfig::current_site_config();
		$base_charge = $this->owner->Total;
		return $base_charge * ($config->GST/100);
	}

}

with the following in the app.yml

Order:
  extensions:
    - GST

The function works as desired, however it is generating a

[Notice] Trying to get property of non-object

Which while not a major problem outside of a dev environment, I am wondering how to stop it coming up. I get the feeling I am missing something very basic here.

If you setup error logging you might see what line of your code throws the Notice.