Duplicate properties in the object - actionscript-3

Question

I'm iterating over the component.nonInheritingStyles (UIComponent) and I'm finding duplicate properties. How is that possible?
var array:Array = getArrayFromObject(myLabelComponent.nonInheritingStyles);
/**
*
**/
protected function getArrayFromObject(value:Object):Array {
var array:Array = [];
for (var styleProp:String in value) {
trace("style:"+styleProp); // fontFamily duplicates a few times
array.push({name:styleProp, value:value[styleProp]});
}
return array;
}

Answer 1

All magic in CSSStyleDeclaration class from Flex SDK.
You can find method:
mx_internal function addDefaultStyleToProtoChain(chain:Object,
target:DisplayObject,
filterMap:Object = null):Object
And you can see code:
defaultFactory.prototype = chain;
chain = new defaultFactory();
This is code contain all magic.
For understand it you can write example:
protected function getArrayFromObject(value:Object):Array {
var array:Array = [];
var parentStyleFactory:Function = function():void {
this.x = 1;
}
var styleFactory:Function = function():void {
this.x = 2;
}
var parentStyle:Object = new parentStyleFactory();
styleFactory.prototype = parentStyle;
var style:Object = new styleFactory();
for (var styleProp:String in style) {
trace("style:"+styleProp); // fontFamily duplicates a few times
array.push({name:styleProp, value:style[styleProp]});
}
return array;
}
This is example will trace:
[trace] style:x
[trace] style:x

Answer 2

If you write this example:
var obj:Object = {x:1, y:1};
var factory:Function = function(){
this.x = 2;
};
factory.prototype = obj;
var obj2:Object = new factory();
trace(obj2.x);
trace(obj2.y);
You will see in console:
[trace] 2
[trace] 1
So, if you try to get value for some property flash try to access to object property, if property is absent, it try to access property from prototype.
But when you iterate in forin by object properties flash return you all object properties and all object prototype properties.

Answer 3

My guess would be is that it is grabbing the styles from the inheritance chain one class at a time and not looking for repeating styles. It just doesn't seem to be the purposes of the function.
The beginning of this component's chain of non-inheriting styles. The
getStyle() method simply accesses nonInheritingStyles[styleName] to
search the entire prototype-linked chain. This object is set up by
initProtoChain(). Developers typically never need to access this
property directly.
SOURCE
Maybe you want inheritingStyles