EmpireProperty<T> class Null safety

Contains any object that will notify any listeners when its value is changed.

Usually these are properties that are bound to a UI Widget so when the value changes, the UI is updated.

You optionally set the propertyName argument to conditionally perform logic when a specific property changes. You can access the propertyName in any event listener registered with the EmpireViewModel.addOnStateChangedListener function via the propertyName property on an EmpireStateChanged object.

If T is of type List or Map, use either EmpireListProperty or EmpireMapProperty. Not doing so will prevet the reset function from performing as expected.

An EmpireProperty is callable. Calling the property updates the value. However, there are two ways to update the value of an EmpireProperty:

Using set:

//initialize the property value to zero.
final age = createProperty<int>(0);

//update the property value to five.
age.set(5);

Calling the property:

//initialize the property value to zero.
final age = createProperty<int>(0);

//update the property value to five.
age(5);