OnChanged_Event Callback feature allows you to manipulate your code with “CustomEvent” when your variable is changed.
Conditions
Events name must start with “OnChanged_.”
The variable you assigned must be Public
Event name and variable after the underscore symbol (_) must be the same
Events names are case-sensitive
Tutorial







Right-click on the Event Graph canvas, type print screen, and select the Print Screen node under the Utilities > String.
Connect the OnChanged_MyBoolean node’s exec output pin to the Print String node’s exec input pin
Connect MyBoolean’s output pin to Print String’s In String input pin and click on the PLAY button

Switch to the RealityHub user interface
Activate the Nodegrap/Actions module
Find and select the ZD ACTOR node