converting class name and passing to another class - actionscript-3

Question

I have a function where I receive map as Class, everything works fine, but when I convert it to string, where map is something like 'IconNorth', convert it to "FieldNorth" and try to pass to another class constructor I get error.
public function newMap(map, x1:int, y1:int):void {
var createMap = new map();
list.push(createMap);
addChild(createMap);
var field = map.toString().split("Icon").join("Field");
new Board(this[field]);
}
and the Board class
public class Board extends MovieClip {
public static var list:Array = new Array();
public function Board(field=null) {
list.push(this);
if (field!=null) {
addChild(new field());
}
}
...
the error is
ReferenceError: Error #1069: Property [class FieldNorth] not found on Map and there is no default value.
I also tried 'getDefinitionByName' but it gives similar error.
So how do I convert a class name with or without using string to another class name and pass it to constructor?

Answer 1

First, you'll need to get the full class, so you can't just use CLass.toString() - in your case that would produce the string: "[class FieldNorth]"
Use getQualifiedClassName to get the full string class:
var classStr:String = flash.utils.getQualifiedClassName(map);
Then, to get the reverse, you'll have to use getDefinitionByName:
var myClass:Class = flash.utils.getDefinitionByName(classStr) as Class
var inst = new myClass();
So, for your example, this is what your code should look like:
public function newMap(map:Class, x1:int, y1:int):void {
var createMap:Object = new map();
list.push(createMap);
addChild(createMap);
var fieldClassStr:String = flash.utils.getQualifiedClassName(map).replace("Icon","Field");
try { //if getDefinitionByName fails, it will throw an exception, not return null
var field:Class = flash.utils.getDefinitionByName(fieldClassStr) as Class
new Board(field);
}catch(e:Error){}
}
public function Board(field:Class) {
list.push(this);
addChild(new field());
}