Comments on: How to use interface in ActionScript 3

By: Weeble

Weeble — Tue, 15 Dec 2009 14:31:30 +0000

very usefull explanation, I’ve struggled to get my head round this for a while now and you helped clear it up. Thanks!

By: brecht

brecht — Fri, 28 Aug 2009 10:42:52 +0000

Well i guess you can just cast to DisplayObject everytime you need a property but still…

By: brecht

brecht — Fri, 28 Aug 2009 10:38:14 +0000

this doesn’t work because you can’t call the displayObject specific parameters like x, y, addEventListener and so on. There has to be another way to make movieclips subject to an interface without losing it’s displayObject specific methods and params. Anyone?

By: Joshua

Joshua — Wed, 19 Aug 2009 22:12:59 +0000

You can also use the “as” parameter.

var newMonster:IMonster = new ScaryMonster ();
addChild (newMonster as DisplayObject);

By: Fraanske

Fraanske — Tue, 14 Jul 2009 18:53:18 +0000

if (monsterInstance as IMonster)
{
// monsterInstance implements IMonster
} else {
// monsterInstance does not implement IMonster
}

trace(monsterInstance as IMonster)
// Traces either a monsterInstance or null

This is the simplest Interface check I could come up with.

By: ad

ad — Sun, 26 Apr 2009 20:34:51 +0000

Just tried this for the first time and found no need for casting.

By: John Giotta

John Giotta — Thu, 16 Apr 2009 13:43:36 +0000

Interace is useful when dealing with shared asset libraries as well. You may refer to the interface class in the application for general definitions of what implementing class will define. Much like intrinsic did for AS2.

By: zedia.net

zedia.net — Sat, 28 Mar 2009 19:50:15 +0000

You can in Actionscript 3 use the is keyword like this:

if (entityList[i] is IBar) {

I have used it and it works perfectly.

By: red tuttle

red tuttle — Sat, 28 Mar 2009 19:01:23 +0000

Is there an easy way to check if a particular object implements an interface?

I have a collection of objects of type IFoo, of which any of them may or may not implement a certain interface, maybe IBar or whatever.

in C# I would do:

if (foo.type is IBar)

But is is not a keyword in CS3

By: steve76

steve76 — Wed, 18 Mar 2009 16:02:26 +0000

@post 10
I think that You never will do a cast in the Paul code.
You can use myMonster as MovieClip or implementation of a IMonster interface without casting in every method that receive as parameters or an MovieClip or an IMonster.

I’m a newbee from the point of view of AS3, but I work with PHP5, C++, Java and so on and that is the main rule ( I suppose so ). am I in fault for AS3?

Bye,Ste