Once or twice a week, I visit the archives of the FlashCoders mailing list to see what folks are talking about. Recently, there’s been a huge thread boiling about using FlexBuilder 2 versus using the Flash IDE. On one hand, like me, some people are super excited about FlexBuilder. I come from a computer science background, and by leveraging Eclipse, Adobe is making me feel more at home. On the other hand, some people could be defined as a developer-designer hybrid. Some of these folks want to understand why the Flex framework and FlexBuilder are so cool to guys like me. Many almost seem angry about the existence of Flex.

First of all, the Flash IDE as it is now isn’t going away. If you can’t understand why Flex and FlexBuilder are so cool, that’s fine. You don’t have to use them. Flash will still be there. The only thing you’ll really be missing is the MXML that Flex uses, but the Flash IDE doesn’t have that anyway, so you won’t lose anything that you already have. In fact, as a developer, you’re probably going to get more coding features. Plus, since the Flex SDK is free, you’ll still be able to use MXML if you really need it. I remember someone mentioned that they didn’t want to buy two different IDEs. The SDK is perfectly usable without FlexBuilder. I’ve already seen some efforts to integrate Flex with programs other than Eclipse.

Some people are saying that RIA and form-based development is possible in the Flash IDE, so why should they use Flex? Yes, you can make everything in Flash that can be done in Flex. It all gets output to SWF, afterall. However, it’s just not as easy. A couple lines of MXML in Flex can replace a classful of event listening and all that jazz. It’s great for results coming from web services because you can bind them without having to write nasty XML parsing code. I haven’t used states much yet, but I’m sure someone can add good reasons why these make form-based development much easier. It seems to me that they help put logic for a single state in one defined place. I know that code can get pretty messy with tons of if-else statements when you have to keep track states in AS2 right now.

The component architecture is also much better than the one in Flash 7 and 8. I know many developers that wrote all their components from scratch just to get better functionality and better skinning. Now, I’m guessing that a lot of people will be more than happy to use the components from the Flex framework. They’re free, they’re powerful, and there’s a ton of documentation. The biggest hurdle will be skinning these components, and it looks there are some tutorials about skinning already.

In the end, it’s up to everyone to decide for themselves if they want to use Flex or not. The best way is to go to Adobe Labs and download the FlexBuilder beta yourself while it’s still free, read through the documentation, and figure out if it fits your needs. Certainly, it isn’t just for RIA developers, but that’s one if its focuses. If anything, it’s a better coding environment with all the features of Eclipse. If you don’t think it will work for you, then that’s cool too.

I’m finding all sorts of little gems in the Flex 2.0 help files. Flex 2.0 supports embedding SVG files just like other images like JPEG or PNG using the [Embed] meta tag:

Flex supports a subset of the SVG 1.1 specification to let you import static, two-dimensional scalable vector graphics. This includes support for basic SVG document structure, Cascading Style Sheets (CSS) styling, transformations, paths, basic shapes, and colors, and a subset of text, painting, gradients, and fonts. Flex does not support SVG animation, scripting, or interactivity with the imported SVG image.

With that in mind, it’s now possible to visually build vector art assets for Flash using open source programs. That’s one of the big things the OSFlash movement has been missing. If you’re looking for a nice SVG program, I’d recommend Inkscape. Does anyone know of other good choices?

While looking through the Flex 2.0 help files, I discovered a great little section on inheritance. Near the bottom, I found a section that covers overriding getters and setters. It included the following code:

package
{
    import flash.display.MovieClip;
    public class OverrideExample extends MovieClip
    {
        public function OverrideExample()
        {
            trace(currentLabel)
        }

        override public function get currentLabel():String
        {
            var str:String = "Override: ";
            str += super.currentLabel;
            return str;
        }
    }
}

You’ll notice that the currentLabel getter calls super.currentLabel. That never worked in AS2. It makes me happy. 🙂

I hadn’t faced a situation like this one in the previous builds of Flex 2.0, but I’m working with some new code. For some reason, I’m getting errors when I use the same variable name but different types for variables that are in different scopes. It’s a pain because its the “i” variable in a for loop. This issue seems to happen only within a single function.

private function scopingIssue():void
{
	if(this.width == 100)
	{
		for(var i:Number = 0; i 
Both those for loops are in different scopes, so they should work as different types, but I get the error, "A conflict exists with definition i in namespace internal". This is definitely a bug. Can someone remind me where to find the bug submission form?
					

I’m working to migrate some code to ActionScript 3, and I’ve come across an annoying problem with inheritance. I’d like some ideas for how to work around it. It’s not a big deal, but I’d prefer not to add a lot of weird casting everywhere.

Here’s a basic example. FruitTree is my base class. It contains a variable called myFruit of type Fruit. I extend FruitTree to make AppleTree. In AppleTree, myFruit becomes an Apple, which is a subclass of Fruit. In AS3, I can’t seem to redeclare myFruit as an Apple inside AppleTree. Just rewriting the declaration in AppleTree (with Apple instead of Fruit) gives me an error, “A conflict exists with inherited definition FruitTree.myFruit in namepace public”. It seems to me that since Apple is a Fruit, things should stay compatible with the super class. I’d prefer to use this method because allows me to use myFruit as an Apple without casting it every time I need to use it.

Here’s an example of what worked fine using AS2:

class FruitTree
{
	public var myFruit:Fruit;

	public function doSomething():Void
	{
		this.myFruit.getEaten();
	}
}

class AppleTree extends FruitTree
{
	//An Apple is still a Fruit, but I want to access some special functions
	//In AS2, this works:
	public var myFruit:Apple;

	public function doSomething():Void
	{
		this.myFruit.removeStem(); //extra functionality
		this.myFruit.getEaten();
	}
}

In AS3, here’s the only way I’ve found to make it work, but requires a lot of extra code because I have to cast myFruit as Apple all the time.

public class FruitTree
{
	public var myFruit:Fruit;

	public function doSomething():void
	{
		this.myFruit.getEaten();
	}
}

public class AppleTree extends FruitTree
{
	//We can't redeclare the variable myFruit as an Apple because we get an error.

	public function doSomething():void
	{
		//Since we can't redeclare it, we have to cast it here
		//I'd rather not have to do this sort of casting a million times
		var myFruitAsApple:Apple = this.myFruit as Apple;
		myFruitAsApple.removeStem();
		myFruitAsApple.getEaten();
	}
}

I also tried building a getter and setter for the property as a work around, but changing the type in the overriding function gives an “Incompatible override” error. It’s probably for the same reason as the code above. Can anyone give me any insights into a way to do what I want? Could this be classified as a bug?