I have installed PhpStorm 2017.2 and created a project and brought up a PHP file. I typed in $parent-> and hit the ctrl-space and I get "No suggestions", I expected a list of available methods. What am I doing wrong?
The problem here is that your class extends XFCP_Forum but this is a fake class and PhpStorm doesn’t know that behind the scenes it extends the Forum controller.
Do you have development mode enabled? The development output system should output a special hint file which PhpStorm can use to figure stuff out.