If you’ve been reading this blog then it should be clear to you that I’m pretty interested in the haXe programming language (if it’s not clear see: Invest Regulary in Your Knowledge Portfolio, Where’s haXe?, HaXe Found!, and HaXe 1.05 Supports Flash Player 9!). My interest in haXe is rooted in my desire to build universally available applications with a code-base that I can grow.

To learn the haXe syntax and language APIs, I wrote a Simple Slide Show application that I call Mediator. Here it is:

You can download the source here.

• the EventDispatcher class demonstrates many elements of the haXe syntax
• background art is externalized in the FLA art/MediatorAssets.fla
• slide data is externalized in the XML document xml/Mediator.xml
• the MediatorModel class demonstrates XML parsing in haXe
• the entire application has a flexible layout (which you won’t be able to notice unless you download Mediator.zip, run the Mediator.swf on your desktop, and resize it)
• Events in the application bubble, this is handled by the Component class’s dispatchEvent() method; that method looks like:

    public function dispatchEvent(event:Event):Bool {
        var dispatched:Bool = dispatcher.dispatchEvent(event);
        if(event.bubbles && dispatched && getParent() != null) {
            getParent().dispatchEvent(event);
        }
        return dispatched;
    }

To compile the simple slide show, first download and install haXe, then download Mediator.zip, and after unpacking it double-click build.hxml.

To run the application locally without compiling, just double-click Mediator.swf.

In comments to the last post Where’s haXe?, iongion did a great job spotting many of the ways in which haXe differs from ActionScript 2.0. Highlights of the differences in syntax follow:

package mediator.events;

In haXe, source code files can begin with an optional package declaration. The files should exist in subdirectories mapping to the package declaration.

    private var listeners:Array<EventListener>;

HaXe uses typed arrays. In the code snippet above, the type parameter <EventListener> means that the listeners array contains objects of type EventListener.

I must have learned something from the first chapter of The Pragmatic Programmer by Dave Thomas (who’s probably better known these days for his contributions to the Ruby community through his publishing company and must-have book Programming Ruby) when I read it long ago. In that chapter, Dave’s 8th tip is to, “Invest Regulary in Your Knowledge Portfolio”. One of the ways he suggests doing so is to learn one new language a year. Well, this year I seem to be making up for years gone by, because I’ve been spending a lot of my extra time working with several different languages and their frameworks. This year, I’ve been working with – in order as of today – haXe, Flash Lite 1.1, Ruby, ActionScript 3.0, XUL, and the Nullsoft Scriptable Install System. I’ve been working with their frameworks Ruby on Rails, Flex, and XULRunner.

All of these languages are tools to build the kind of software that I’m interested in building: software that’s fun to write, easy to distribute, a pleasure to use, useful, and affordable. For software to be distributed easily and a pleasure to use has to be universally available. And, to be universally available it needs to be truely cross-platform – cross-software and cross-hardware. It needs to work on win, mac, and nix and also in a browser, on a desktop, and on a palmtop. Today, the best format to make software universally available is the SWF format. It’s undeniable, more people have the Flash Player than any other piece of software .

It is, granted, worth noting that some feel like traditional Java, non-traditional Java, Python, Ruby, .NET, and the Mozilla Foundation’s XUL are also acceptable tools to make available software, and depending on the goal, they’re correct. In many cases, these technologies can even enhance a SWF’s funcionality. For example, it’s possible to use Mozilla’s XULRunner as a desktop wrapper for SWFs, or if you’re really smart, to do what Rich Kilmer did and write a SWF view to a Ruby controller and Berkeley DB model. Rich gave me and Luke a sneak peak at his indi product at RailsConf, and we were blown away. The product is a great idea, and it’s built on an extremely smart and interesting architecture. Get indi when it’s available.

Invest regularly in your knowledge portfolio.