Singleton-esque, self-aware ‘Kind’ Classes

Dusty — Tue, 09 Sep 2008 00:49:46 +0000

I recently started a project of converting an older flex app to an AIR app. This app has to scan through a bunch of files, and classify certain types of media based on the location and file extension. Then it saves a manifest of the media to an xml file that can be loaded (without scanning every time).

I started out with a Kind class (think CollectionEventKind) that had the types as strings… but then I had to figure out how to store the regular expressions to make them easily accessible… Then I remembered that while everyone just uses Strings, static const vars can be any class, including it’s own class. So I came up with this class that you can use constants, or locate a specific constant. Code after the fold.

package aero.panasonic.training.model { import flash.utils.Dictionary; import flash.utils.describeType;


	public class MediaKind

	{

		public function MediaKind(title:String, label:String, regex:RegExp ){

			this.title = title;

			this.label = label;

			this.regex = regex;

		}

		public function toString():String{

			return title;

		}

		public var title:String;

		public var label:String;

		public var regex:RegExp;

		public static const D_ILLUSTRATION_PERSPECTIVE:MediaKind =

			new MediaKind("Illustration - Perspective", "Perspective", /Deliverables\/Illustrations\/Perspective\/.*_perspective\.(?:png|swf|jpg)/i );

		public static const D_ILLUSTRATION_THREEQUARTER:MediaKind =

			new MediaKind("Illustration - 3/4 (ISO)", "ISO", /Deliverables\/Illustrations\/Isometric\/.*_iso\.(?:png|swf|jpg)/i );
		private static var lookup:Dictionary = new Dictionary();

		private static var allKinds:Array = new Array();

		private static var kindsMapped:Boolean = false;

private static function mapKinds():void{ var description:XML = describeType(MediaKind); for each(var cXML:XML in description.constant){ var m:MediaKind = MediaKind[cXML.@name] as MediaKind; lookup[m.title] = m; lookup[m.label] = m; allKinds.push(m); } kindsMapped = true; } public static function getMediaKind(input:String):MediaKind{ if(!kindsMapped) mapKinds(); return lookup[input]; } public static function getAllKinds():Array{ if(!kindsMapped) mapKinds(); return allKinds; } } }

In my code, I have a piece that gets all of the MediaKinds, then checks each file against each kind. I can filter, I can create drop-downs, all from one class. The getMediaKind() function lets me effortlessly create my ValueObjects from XML. The toString() writes out the title, making my XML human-readable.

Instinctively, I want to take this farther and create a base ‘Kind’ class that has this all in it. It turns out that static properties/functions aren’t inherited. The properties and functions are still in scope, however… so it may be possible to write a generic function that takes a class, creates a lookup for that specific class and passes it back down the line, allowing the allKinds() function to return ALL of the static definitions for the class and it’s super-classes. Anyways, that’s too much for my head at this point, but maybe someone else will take the bait

Debugging AIR Drag and Drop

Dusty — Sun, 11 May 2008 23:59:03 +0000

So… you thought you’d be cool and throw a break point on some DRAG_ENTER code, but after you’re done debugging, you’re left with a little floating icon on your desktop.

Never fear, you don’t have to restart your entire computer, open up Taskmanager and you’ll see an application called ‘Drag’. You can kill this application and the icon will disappear. If you don’t see this app, close Eclipse and find the process called ‘adl.exe’ and kill this process.

Restart averted, Yay!

h6 - HatSix » AIR

Singleton-esque, self-aware ‘Kind’ Classes

Debugging AIR Drag and Drop