I would say it's more flexible to use the ClassFactory because you can
dynamically set the properties in the ClassFactory. Simple example:
Say you had an application that creates Squares - just simple rectangles
on the screen. When the user presses a button, a new square pops up in
a random location. If you used a hard-coded class to fill your Square
class with pre-set instance data, you're locked in to your
implementation. You'll have to write a new class if you wanted to give
the user the option to create a RedSquare instead of a Square. It gets
exponentially difficult if you have multiple things that might need to
change as well: say color, size, border-thickness, etc. You'd have to
make a new class (and then configure your application to use that new
class!) for each property of Square. Not pretty!
[Pseudocode]
var newSquare:Square;
If (userInput.color == "Red")
square = new RedSquare();
else if (userInput.color == "Blue")
square = new BlueSquare();
else if (userInput.border == "Thick" && userInput.color == "Blue")
square = new BlueSquareWithThickEdge();
etc...
etc...
[/Pseudocode]
With the ClassFactory, you could just update the
myClassFactory.properties variables:
[Pseudocode]
var properties:Object = new Object();
properties.color = userInput.color;
properties.edge = userInput.edge;
var myClassFactory:ClassFactory = new ClassFactory(Square);
myClassFactory.properties = properties;
var mySquare:Square = myClassFactory.newInstance();
[/Pseudocode]
It doesn't look a whole lot smaller now (it gets a lot better when
you're add a few dozen more else-ifs to the first attempt), but it's far
more elegant as well IMO.
Jonathon
From: [email protected] [mailto:[EMAIL PROTECTED] On
Behalf Of valdhor
Sent: Friday, May 30, 2008 10:05 AM
To: [email protected]
Subject: [flexcoders] Re: What is a classfactory and why would I use
one?
Ok, that makes sense.
What is the benefit of going the classfactory way instead of extending
a class and setting all the properties in a class constructor?
_
