Nonfunctioning "for loop" for addressing each variable of class - actionscript-3

Question

I'm learning AS3 but have some antiquated background in programming (TP and Atari Basic). On this forum I learned to use a loop such as the one below to address each variable in an object class, in order to make a clone of the object (deep or shallow) or in my case to build the text for a tooltip. However mine doesn't work. Here's the loop, following is an explanation, any help you can give I'd appreciate greatly!
var tooltipText:String;
var i:String;
for (i in bsm) {
if (!(bsm[i] is String)) {
if (bsm[i] != 0) {
tooltipText = i + ": " + bsm[i];
tooltip.extendTooltip(tooltipText, 0xFFFFFF);
}
}
}
Please forgive the horrible variable names. 'i' is a String. 'bsm' is a non-null instance of class StatMod, which begins with
public class StatMod extends Object {
public static const ENCHANTMENTMODIFIER:String = "enchantmentModifier";
public var enchantmentType:String = "None";
public var enchantmentDescriptor:String = "None";
public var minDamage:Number = 0;
public var maxDamage:Number = 0;
public var attackSpeed:Number = 0.2;
The intended behavior is to go through each of the variables of StatMod (I'm not showing them all and I will add more later), and if the variable is a non-zero number, make a string ("attackSpeed: 0.2" for instance) and then add that string to the tooltip. The tooltip.extendTooltip function is working properly.
The observed behavior is basically the computer believing that there are no variables in bsm.
What can I say or do to convince the computer that there actually are variabels in bsm?

Answer 1

The behavior you're expecting is only the case when iterating over dynamically attached properties. For example, if you marked your class dynamic:
public dynamic class StatMod { }
Then added some values to it at runtime:
bsm.test = 5;
Your loop will find the property test with the value 5.
Some options you have to achieve what you want are:
Extend the Proxy class to define what properties are iterable via nextName and nextNameIndex.
Use describeType to generate a list of all the public properties.
Though a simpler method is to expose a list of the properties you want to iterate over and use that in your loop instead, something like:
public class StatMod {
// Existing properties etc.
private _properties:Vector.<String>;
public function get properties():Vector.<String> {
if (_properties === null) {
_properties = new <String>[
'enchantmentType',
'enchantmentDescription',
'minDamage',
'maxDamage',
'attackSpeed'
];
}
return _properties;
}
}
Then:
for (var i:int = 0; i < bsm.properties.length; i++) {
var prop:String = bsm.properties[i];
trace(prop, bsm[prop]);
}