15.2. Dynamically Adding New Behavior to an Instance

Having just learned how to create dynamic instance variables, you might wonder whether ActionScript also supports dynamic instance methods—adding a new instance method to a single, specific object without adding it to any other instances of that object's class. In fact, there is no formal means of adding a true instance method to an object dynamically. However, by assigning a function closure to a dynamic instance variable, we can emulate the effect of giving an individual object a new method (for a refresher on the term function closure, see Chapter 5). The following code demonstrates the general approach:

someObject.someDynamicVariable = someFunction;