What is or isn't possible on iOS? (Not having Loader, loadBytes(), external swfs, etc)

Question

My basic question is:  "What are the classes which we should not use for iOS using the packager."
I have been trying for a few days trying to get a simple Flash app to run on the iPad.  A very simple app (with sound!) with just 2 classes works fine (Performance is a whole other issue.  We will get to that).  But if I try anything else, all I get is a white/black screen on the iPad.  So it would be really nice to know what classes, functions, etc we CANNOT use for the Packager.
I have fairly simple app (not as simple as 2 classes) which loads some art assets via URLRequest/Loader, puts them on the stage.  Fairly common standard practice in AS3.
I've read about not able to load an external file using the Packager.  So to fix the situation of loading assets, I have looked into the [embed] tag, which seems to work.  I hope the blogger doesn't mind, but this page is an excellent source on what works and doesn't work with the [embed] tag in it's various flavors:  http://www.richardleggett.co.uk/blog/index.php/2010/03/08/flash_builder_and_flash_pro_asse t_workflows.  For example, AS3 in a swf is stripped out from an external swf using [embed].
The best way to load an external swf file for iOS seems to be using [embed] with "application/octet-stream" and load the swf through ByteArray (Option #4 in the link above).  This works great on the PC.  HOWEVER, on iPad, it fails.  The [embed] tag works on the iPad with the other ways, so my guess is that loadBytes() does not work.  Is this true Adobe/Flash guys?  Can you confirm this?
My initial question is "why is this not allowed on iOS?".  If it is because of the fact that it uses a Loader, can it be changed so it's not using a Loader to construct a MovieClip?  I have a ByteArray with the raw swf/MovieClip data.  Why can't I construct a MovieClip from it without going through Loader?
This loadBytes() failure seems to be the only thing preventing me from using the normal pipeline of Flash development in loading external assets.  If there are other ways people have found, please share!
Now on to performance.  Adobe, can you post some examples/samples of code which runs at decent performance?  Like a "tech demo" of what is possible using the Packager running on iPad/iPhone.  That would be extremely helpful for everyone.  I have done a lot of the optimizing suggestions on various sites and pages ( and by Adobe http://www.adobe.com/devnet/flash/articles/optimize_content_ios.html), but I am not seeing the 30 fps performance that is MORE than possible on iPhone/iPad.  Displaying and moving around Bitmaps (I don't use any vector graphics) should be blazing fast.  Quake runs on iPad without any problems and that code is 10 years old.  Moore's law dictates that drawing Bitmaps using CPU should be faster than a 3D engine written 10 years ago...  I am trying out the new iOS 4.2 which is supposed to be "significantly" better, but I am still stuck on loadBytes().
So at this point, I am blocked on loadBytes() and my performance for a simple app which draws a few Bitmaps and MovieClips is terrible.  I am hopeful some people out there have figured out some solution (there are lots of clever people out there) and I will stumble on to something.  But being forced to go native Objective-C seems to be my only option at this point.
In summary, here are the questions I would like to ask the Adobe/Flash group for some more help/information/advise:
- Why is Loader not allowed on iOS?  Is it a technical limitation of the hardware/os/Flash?  Will it never be supported?  What is the future of this class on iOS?
- Why is loadBytes() not allowed on iOS?  I have the raw embedded data in memory.  I don't need to make a remote call so security should not be an issue.  Can I create a MovieClip without using Loader?
- Why is AS3 stripped from the timeline when a Symbol is retrieved using [embed]?  Maybe this is the same reason loadBytes() fails, but if I could use [embed] and get a copy of the Symbol, that is what I need.  (There are issues with the mx.core.MovieClipLoaderAsset/Asset, but it is better than being blocked by loadBytes())
- What are some apps you guys have written that we can use to compare PC vs iOS?  Again, a "tech demo" or sample code of what you as experts in Packager for iOS have done which runs at decent framerate (30+fps) would be of tremendous help.  If the Adobe/Flash group hasn't gotten the current Packager for iOS to handle more than 50+ 2D Bitmaps on screen running at 30+fps, that would be good to know.  Please let us know what the experts and owners of your software are capable of getting the most throughput using the Packager.  I'd hate to sound a bit fed up/angry, but I think you are wasting a lot of people's time and energy with a piece of software that, to me, seems like it was a bit early to release.  Flash can do some great things.  If it can do it on iOS, even better.  But PROVE it to us that it's possible, before having your customers run into barriers imposed on us by trial and error.
Thanks.

Answer 1

I have hardly ever seen a post here from someone at Adobe, so you may need to be patient.
Read this article, and get its associated demo files, to see some good performing tech demos:
http://www.adobe.com/devnet/flash/articles/optimize_content_ios.html
Back to your main point, loaders are working, what isn't working for you is accessing of things in the library of a successfully loaded swf, that have been set to Export for ActionScript. That means that the swf you have loaded has an ActionScript Class, to represent the library symbol. iOS Flash apps are native ARM code, and don't include the virtual machines that a browser plugin has, and so it's not able to interpret ActionScript. That may be why it would fail.
Now, I can think of at least a couple of reasons why you might want to have external swfs with elements that you want to reuse in the main swf. One would be if you're intending to make a lot of them, like say if you wanted to have an Asteroids game and the ability to use artwork from a set of different swfs. Another reason might be if you want to skin your interface, by taking specific elements from the loaded swf and using them in the main swf. That way you could have artists preparing those swfs for you, and you just include them in your package, and load the one you want.
There is a way to do either of those things. The second one can be done by having the item as a named symbol on the stage of the loaded swf. With a to-be-loaded swf named "inner.swf", that has a movieclip on its stage named "mc1", this script in the main swf would load that external swf and use its symbol on the main swf's stage, without having to make the inner swf's symbol use ActionScript:
var req:URLRequest = new URLRequest("inner.swf");
var ldr:Loader = new Loader();
ldr.contentLoaderInfo.addEventListener(Event.COMPLETE,loaded);
ldr.load(req);
function loaded(e:Event) {
var mc:MovieClip = e.target.content as MovieClip;
var innermc:* = mc.mc1;
innermc.x = 50;
innermc.y = 50;
addChild(innermc);
For the other case, you can take the item off the stage of the loaded swf and draw it into a bitmapdata, and then make as many bitmaps from that as you like. Here's the above example, only it adds the original movieclip to the main swf stage, and also creates a bitmap that looks the same:
var req:URLRequest = new URLRequest("inner.swf");
var ldr:Loader = new Loader();
ldr.contentLoaderInfo.addEventListener(Event.COMPLETE,loaded);
ldr.load(req);
function loaded(e:Event) {
var mc:MovieClip = e.target.content as MovieClip;
var innermc:* = mc.mc1;
innermc.x = 50;
innermc.y = 50;
addChild(innermc);
var bmd:BitmapData = new BitmapData(innermc.width,innermc.height);
bmd.draw(innermc);
var bm:Bitmap = new Bitmap(bmd);
bm.x = 150;
bm.y = 150;
addChild(bm);
So, the thing to learn is that a native ARM code application does not have an ActionScript interpreter in it, and if you need to do something that normally requires interpreting ActionScript, find another way to do it.