Class Factory pattern help

programming flash
1

I’m back to actionscript after many years in hiatus.

I want to create a loader class that I can use to load class dynamically at runtime. Basically, a factory pattern class.

It will work something like this:


package
{
  import runtime_loader;
  import app_controller;
  import my_error;
  public class foo
  {
     var _controller:app_controller;
     public function foo(controller_name:String)
     {
          _controller = runtime_loader(controller_name);
          if (!_controller)
          {
             throw my_error('fool!')
           }
      }
    }
  }

My current runtime_loader class basically has a switch that decides the class to return. I would like to make it as clean as possible. Currently, it looks something like:


switch(name)
{
  case 'foobar':
    return new foobar;
  case 'bezfoo':
    return new bezfoo;
  default:
    return null;
}

It would be sweet if I could do something along the lines of:


try
{
  return new $name;
}
catch (invalid_class)
{
 ...
}

Is there any way to include all the classes that fall under a top level package, even the one in sub packages?
like: import.** ; // I know this is invalid
Any help with creating a factory class would be sweet.

2 
try {
	var clas:Class=getDefinitionByName(someString);
	var instance=new clas();
} catch (error:Error) {
	trace("Class doesn't exist")
}
3

Thanks