[AttributeUsage(AttributeTargets.Method, Inherited = false)]public class OnComponentChangedAttribute : Attribute

The method must be , and a component may declare at most one. The source generator emits notifying setters for the component's fields; each one flags the owner so this handler runs once in the next update, no matter how many fields changed. Use it to invalidate the owner — for example , a layout request, or recomputing a cached value. The handler never runs from inside the setter, so a burst of writes in one frame coalesces into a single call.