code: public function onExecuteAction(ExecuteActionEvent $event){
  		$request=$event->getRequest();
  		$position=1;
  		foreach($request->getConfig()->getArray('argument') as $argument){
  			$this->validateArgument($request,$argument,$position++);				
  		}
  	}
docs: Detect config argument.
  
  @param ExecuteActionEvent $event