AS 3.0 Coming From 2.0 - Article 1

The Problem:

For most purposes, the word developer means coder. Flash is different: 90% of Flash Developers are actually graphics/animation experts that only use light ActionScript 2.0. There is no shame in this. Flash is an extremely broad program, and needs experts in each of it's many areas. These animation gurus got by with an basic knowledge of AS 2.0 or 1.0, and did that only because is was a fairly simple language to get the basics of, and it afforded them some interactivity. Then came the beast. ActionScript 3.0 is a different kind of language, a language that involves more than a little memorization as you go. AS 3.0 was built from the ground up for coders.

There are lots of 3.0 tutorials on the web for the major advanced concepts that have changed, but the basics are being overlooked. I have a solution: AS 3.0 Coming From 2.0. We will go over scripts commonly used by animators and light flash programmers in AS 2.0, then show how, why, when and where to do the equivalent in 3.0. If you are an AS 2.0 expert, some of this will also help you, you'll just have to put up with all my explaining of the concepts, which you'll already know.

REMEMBER! The help section is your friend! I'm an expert coder that builds large and complex programs, but even I have the help section on a tab right beside my actions panel. It's not like Word, where help is where you go when you don't know what your doing, it's more like a complete AS dictionary at your fingertips.

Lesson 1: Paths

Most 2.0 programmers that begin learning 3.0 run into this issue first: _parent (now just parent) and _root (now just root) don't work as planned. Make a movie clip, and inside it, put:

1. // this is inside a movie clip, trying to call to the main timeline
2. parent.gotoAndStop(2);

1. // declare a variable that is parent
2. var myParent = parent;
3. // apply that instead of just using the command parent itself
4. myParent.gotoAndStop(2);

1. import flash.display.MovieClip;
2. import flash.utils.Timer;

1. // movie clip with instance name myClip_mc changed to 50% opacity in AS 2.0
2. myClip_mc._alpha = 50;

1. // movie clip with instance name myClip_mc changed to 50% opacity in AS 3.0
2. myClip_mc.alpha = .5;

1. // script to give a button an action in 1.0, placed directly on the button
2. on (release)
3. {
4. doSomething();
5. }

1. // script to give a button named myButton an action in 2.0, on a frame, using a path
2. myButton.onRelease = function()
3. {
4. doSomething();
5. }

1. // script to give a button named myButton an action in 3.0, on a frame, using a path
2. function ClickHandlerFunction(event)
3. {
4. doSomething();
5. }
6. myButton.addEventListener(MouseEvent.CLICK, ClickHandlerFunction);

The function is just a declaration of a normal function, but takes one argument, since the listener passes one when it is dispatched. You don't need to use that argument, just be ready to accept it without error.

The addEventListener part gets a little tricky. First of all, make a path to where you're listening for, just addEventListener will just listen to the object that owns that frame, normally the main timeline. myButton.addEventListener will add it to the button, so you are watching that button, waiting for the event to happen to it.

The MouseEvent.CLICK part is what you are listening for. There's a million (slight exaggeration) events that can be watched for. What most light programmers use are MouseEvent events. When you type in MouseEvent and then the period in there, it will show the list of all the different ones you can use for mouse related events, different ones are triggered at different times. Experiment, you'll figure out what is what. The help menu helps too (hence the name help menu).

The ClickHandlerFunction part is easy. That's the name of your function. No parentheses are needed, you don't get to decide what arguments get passed, it passes the event whether you like it or not, and nothing else. There are many properties of the event that you can use to figure stuff out, but that is above the scope of this tutorial, this is for the simple stuff only.

There will be more of these tutorials in the future. The intent is to make a 2.0 to 3.0 transition easier for the average Flash user. I hope it helps!

This has been a tutorial by:

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(='.'=) <------ Mad Bunny Skills
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Bryan Grezeszak | of Elemental