1

I've set up an XML file with names of objects that will be contained in a fla/swf library. I wish to position the objects on the stage using an XML file that can be quickly modified without having to recompile the fla/swf file. Of course, positioning can only be accomplished when the objects are instantiaed and added to the stage. The problem is passing the parsed XML file name/class paring data into the var creation programatically.

The XML file contains the object names and class: example follows:

<objects>
   <object name="myBall" class="Ball"/>
</objects>

The XML file parses correctly and I've set up a ...for...each loop to assign the name/class to each object. The problem is with the proper syntax to input the name/class paring, something similar to the following:

var object.@name:object.@class = new object.@class();

Am I off my rocker with this or just temporarily ignorant???**

Improve this question

3 Answers 3

Reset to default
4

Just a quick follow up, there's a quite straight forward way to keep it flexible :

var xml:XML = <object name="myBall" class="Ball">;

// Looks up for a defined symbl/definition with the name 'Ball'    
var Def:Class = getDefinitionByName(xml.@class);

// Creates the instance of the Ball
var instance:* = new Def();

// in case you want to assign a name to the node as a reference on the display list :
addChild(instance).name = @xml.name;
Improve this answer
Sign up to request clarification or add additional context in comments.

1 Comment

Thanks to all for your response. All responses were in the ballfield but this one was spot-on for what I needed. Nemaste - Archie
1

I'm not certain what you're trying to do.

Do you want to create an object with the name myBall that is of type Ball?

var object:Object = new Object();
object[objects.name] = createNewClass(objects.class);

...

function createNewClass(var name:String):Object
{
    if(name == "Ball")
        return new Ball();
    ...
}

Not sure if this is what you're trying to do. I don't know if there's a way to create a new Ball just from text, if anyone knows a way to do that, I'd also like to know how.

Improve this answer

1 Comment

Thanks for your quick and accurate response. Archie
0

Based on what you're asking, it sounds like you're attempting a type of Factory-pattern (Factory Method) where a class is responsible for dynamically generating objects based upon information given from an external source.

I would recommend looking into Design Patterns for Flex and ActionScript. I haven't written a Factory Method in Flex yet, but it can't be much harder than Java, which isn't too bad.

In general, here's what I would expect your program to look like:

  1. Your XML describes the object which will be generated (class type, params, etc.). Your example appears to show this.
  2. You have an XSD which can verify the XML file conforms to your program's expectations -- if it doesn't, an appropriate error would be outputted. I would highly recommend something along these lines for validation: you need to have a mechanism which guarantees the XML is correct.
  3. You've abstracted the values you are expecting to be in the XML. I would recommend using Enums or static/constant String values in a separate utility class.
  4. You have a Factory class whose sole responsibility is to take in the XML data, generate the objects based upon the contents, and return it to whoever needs it.

The 4th point, obviously, is what you are looking or (I think). CookieOfFortune's example shows what this Factory Method might look at. I would, however, recommend you also abstract out the String values into a variable or Enum:

...
var BALL_CLASS_TYPE:String = "Ball";
...
function createNewClass(var name:String):Object {
    if (name == BALL_CLASS_TYPE)
        return new Ball();
}

Your first parameter, however, is confusing to me. It sounds like you're trying to create a dynamic object with a dynamically-named reference to it (e.g. var <x>:Object where <x> is defined as data in the XML). I don't know if this is even possible. I would certainly think it not necessary.

Improve this answer

1 Comment

Thanks for the detailed response. Your comments are well-received and will be considered for the final. Much appreciation Archie

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.