Timer vs setTimeout

Question

The docs for flash.utils.setTimeout() state:

Instead of using this method, consider creating a Timer object, with the specified interval, using 1 as the repeatCount parameter (which sets the timer to run only once).

Does anyone know if there is a (significant) advantage in doing so? Using setTimeout is a lot easier when you only need to delay 1 call.

Solution 1

setTimeout actually uses a Timer subclass, the SetIntervalTimer, which is an internal class. You can check by doing setTimeout(function ():void { throw "booom"; }, 1);. You'll see it in the stack trace.

As such, I cannot really see a big disadvantage. The only difference is, that you have 2 anonymous calls instead of one. OTOH, in performance critical situations, you shouldn't be using either (except one internal timer) to avoid frequent instantiation of TimerEvent objects.

Basically, I think it's a matter of taste. Adobe decided, the AS3 event system is the shizzle, so they promote it.

Solution 2

Timer:

• Gives you more control as you can register more event listeners to receive the event rather than a single one with setTimeout

• You can control the start time and
  the number of repetitions ( not very useful against setTimeout, as this
  has to run just once and after a
  delay considering the immediate time it was called)

• More lines to write, even more if you need to differentiate with parameters ( custom event class for this )
• Use of event listeners which is
  standard practice in as3.
• Cleaner look

setTimeout:

• Easier to use

• Less code to write

• Parameters can be easily sent;

I prefer the Timer class but I've seen setTimeout being frequently used by programmers.

Also if you are using Tweening libraries,some support delayed call

For example TweenMax TweenMax.delayedCall(2, myFunction, ["myParam"]);

For all those who say that setTimeout is deprecated, this is non sense..

http://livedocs.adobe.com/flash/9.0/ActionScriptLangRefV3/flash/utils/package.html#setTimeout%28%29

I believe you can't see any "deprecated" keyword around setTimeout here

Solution 3

setTimeout is working perfectly well in external .as files.

Just use this in the class :

import flash.utils.*;
import flash.events.TimerEvent;

Comments

[back2dos]

hi . nice to see you here :) anyway: could you go a little more into detail? what do you mean by "external"?

[back2dos]

generally a good reasoning, but unlikely to happen with flash player. adobe really cares a lot about backward compatibility and legacy support. also, in this case, one can rewrite the function within a couple of lines.

[Martin Konecny]

@back2dos, yes you are right in the case with Adobe, but why not follow good practices in general?

[Cristi Băluță]

By external .as files i mean classes. Is anyone here using as3 without classes? PS: Do we know each other?

[back2dos]

Strange. Works perfectly for me, no matter whether compiled with the IDE or mxmlc. PS: not personally, but from the haXe mailing list. :)

[Cristi Băluță]

Oh, sorry for the misinformation then, seems i can't reproduce it myself. Probably the compiler was confused by another error and gave me this one. Was for a flash project after 2 years of programming only in haxe :P

[back2dos]

what other than Adobe's opinion makes timers a better practice than setTimeout? I agree, a Timer offers more possibilities then setInterval and setTimer, but then again, AVM2 bytecode offers more possibilities than ActionScript :D I think setTimeout is a useful function. If it weren't there, I'd write it on my own. To me, it is good practice for code to be concise, because that makes it readable and understandable. so while I generally agree, deprecation is usually to be taken seriously, in the case of ActionScript 3, I often feel it's really just a matter of taste.

[Oliver]

I was just going to correct you after a talk with Virusescu :)

[Pier]

setTimeout works perfectly in any .as file. Just import flash.utils.setTimeout