One solution is to change the value of the boolean by using the value(signaling) property. Unlike e.g. changing the value using a local this will trigger an event (events like this only trigger when there has been a user interface activity, that's why using a local won't work).
The other solution is to add your own user defined event and then set that event prior to doing anything else in the application. Check out the user event examples to see how you create and trigger such events.