[Codemonkey]

 
A less known and even less used feature in actionscript is the __resolve method.

If you declare a method called __resolve on your class and someone tries to call a property or method of your class that doesn't exist, flash will look for a __resolve instead and call that one. You will get a parameter with the name of the unknown property/method that the user is trying to call. In addition, you can use the arguments variable inside __resolve to uncover any arguments the user passed.

You can call properties/methods that don't exist on an object when:

1. Your class was declared dynamic

   dynamic class MyClass {
   function __resolve(name:String) {
   // do something
   }
   }
   var instance:MyClass = new MyClass();
   instance.unknownFunction() 

2. You use an Object directly

   var o:Object = new Object();
   o.__resolve = function (name) {
   // do something
   }
   o.unknownFunction() 

3. You typecast an instance of your non-dynamic class as Object (this won't work in AS3.0 though)

   class MyClass {
   function __resolve(name:String) {
   // do something
   }
   }
   var instance:MyClass = new MyClass();
   Object(instance).unknownFunction() 

__resolve can be useful in case you are creating dynamic classes for distribution and you want people to know when they called a non-existent function - which the compiler would've done if your class wasn't declared with the keyword dynamic. Or you could use __resolve to forward method calls to a server or act as an adaptor to other objects. In doing so you can also log all methods being called through __resolve in a single place. Another use is when you have a 'decorator' and you need to forward dynamic methods 1-on-1 to the 'decoratee'.

Be cautious though, __resolve doesn't *always* work as you would expect and you should have a very specific reason where you think __resolve is the solution.