Goodies for Flex2 Developers

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I was invited by Adobe to join them in San Francisco for the two day Adobe Component Developer Summit (ACDS) last month. The event was a blast to say the least, surely the best developer get-together i’ve been to ever. I got to finally meet people that i know for many years now but never met before (you know wo you are), and the presentations were all very solid.

Ted Patrick (he set the whole thing up and receives my special thanks once again: was great meeting you, Ted) announced today that the speakers made their slides (and sample code where applicable) available to the public. It’s absolutely a great resource for developers who want to get their feet wet with Flex 2, or who want to dig deeper. My personal favourite presentation was Gary Grossmans “ActionScript 3.0 and AVM2: Performance Tuning” [PDF].

Check out Ted’s post “Adobe Component Developer Summit – Slides and Examples” for the download links.

[Oh and by the way, in case you missed it, the price winning and dug Commodore C64 emulator project FC64 that Darron Schall and myself have been working on in our free time for a while now is an open source project so feel free to check out the sources to see how we did it. Maybe you even want to contribute.. please drop me or Darron a mail, we greatly apprechiate your input]

Innovation, or the lack thereof… W3C, anyone?

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I originally posted this on the OSFlash mailinglist, but i thought it would make a good blog post, so here it is:

My vision of a next generation web application framework.

(or: Innovation, or the lack thereof… W3C, anyone?)

There’s a sh*tload of XML dialects for GUIs either available or being developed at the moment. Just to name a very few: Adobes MXML, Microsofts XAML, Laszlos LZX, Netscapes XUL, and from the OSFlash camp ActionSteps ASML (or Renaissance) and ASWings AWML.

All of them are proprietary formats (plus most of them are direct projections of the underlying, proprietary APIs), and all of them require some decent amount of script code to be written in order to actually make the UIs work. Problems: to author sophisticated applications i need extensive knowledge of the XML dialect itself, of the API and the scripting language, and probably of the underlying platform API too. For most ‘next gen’ RIA platforms much of this is proprietary stuff, so i better choose wisely what technology to dive into for the next months/years. I also better be able to think ‘code’ in order to make my RIA a successful reality.

Wouldn’t it be nice to develop web applications using open, standardized technologies that everyone is already very familiar with? Let me introduce you to the W3C, and please try to forget about browsers in general and men with white beards wearing birkenstocks in particular for a moment.

Contrary to popular belief, the W3C is working on really cool stuff. Some of it you’re already very familiar with: (X)HTML and CSS. The *real* cool stuff though are W3C technologies that haven’t made it into the mainstream yet (because they aren’t supported by mainstream clients, or because they’re being worked on yet). I pick two of those technologies, XFrames and XForms, and briefly introduce them here, as i think that together with XHTML (2) and CSS (3), they pretty much cover everything a RIA framework needs.

XFrames
The technology that is supposed to supersede HTML Frames. XFrames of course is going to support framesets as we know (and hate) them today, but there’s so much more. Using CSS, frames can be styled to appear as floating windows or tabbed panes for example, and using a new URI scheme it will be possible to easily link not only a frameset but also it’s content, example: http://example.org/index.xframes#frames(id1=uri1,id2=uri2,...).

XForms
The technology that is supposed to supersede HTML Forms. XForms is going to significantly change the way we author forms. Basically, it separates the model from view and controller, as you can now have multiple data instances (usually XML, both inline or external) that you can use as data provider for controls and widgets (controls can be bound to data provided by instances using XPath). Validation is handled in a purely declarative way via XML Schema datatypes. But again, there’s much more, for example: <switch> and <case> to show/suppress parts of the UI (to be used for e.g. wizards, tabbed interfaces or dynamic forms), or <repeat> (to be used for e.g. filling tables with rows, or datagrids, or just about anything UI that repeats itself). Of course everything is styleable by CSS and can be bound to data instances. Sounds familiar? It sure is. And did you know that the latest ColdFusion uses XForms under the hood? Yes it does.

I recommend the W3C articles “XForms for HTML Authors” (Part 1 and Part 2) and Micah Dubinkos XForms Institute (hey look, he’s using DENG!) for a leightweight introduction to XForms (The XForms Institute also links a free online version of the O’Reilly book “XForms Essentials” in case you’d like to dive in further)

If you mix all those technologies mentioned above, and throw in some more, like SVG, SMIL, and maybe even XUL, that’ll be my vision of a sane platform for Web 2.0 [sm][tm](c)… ok, Web 3.0 it is then. A sane platform to develop RIAs on. Don’t even get me started ranting about the current state of the web as too many people see it. What the web needs is innovation, not hyped acronyms for old crap, or yet another proprietary markup language.

Of course such a framework needs to be developed yet. With the Flash Player 9 in our hands, the great performance boost compared to version 8 and a way better API (minus native text rendering.. still sucks), i’m sure it’s absolutely doable. If only somebody with some angel $$ would share my views, or if only everybody would work together with open minds instead of cooking their own soup…

We even have a proof of concept, anybody remember DENG? That was Flash Player 6. I’m also writing all this because i think most people misunderstood DENG and see it as a better HTML-enabled TextField or something, or worse, as a HTML browser. It was supposed to be the beginning of an application framework. Of course it’s missing A LOT yet to really become one (and of course Flash Player 6 was way too slow to do such stuff), but again, with Flash Player 9 and some likeminded developers, this could become quite a blast.

Thanks for listening :)

Addendum: Some good and valid remarks and questions i got in the OSFlash mailinglist:

This is, in my mind, a brilliant idea especially when you throw in Haxe‘s planned ability to render to different (and future) runtimes (I assume that you would use Haxe to do this).

One of the most frequent issues on the Haxe list is the lack of a component written for Haxe. I think that a project like this would solve that issue for Haxe.

I’ve looked into Haxe. It sure looks promising, and It’d be a major plus that a framework written in Haxe potentially wouldn’t have to be tied exclusively to the Flash Player. The first thing i would do if i would start to develop such a framework in Haxe is write a compliant DOM3 Core implementation that works exactly the same in Flash 6, 7, 8 and 9 and in all mainstream browsers. That alone would already kick some serious bottom.

I glanced through the XForms documents on w3c and was wondering if it would be possible to leverage one of the existing component sets (specifically ActionStep or ASWing) to complete this task? To me, it would seem like a much smaller job if we used an existing framework.

But could we imagine to bind a standard Flash XFrames/XForms/CSS parser with any/a few GUI toolkits? That would actually be great, but is it possible to achieve?

I have been asked this question many times already. Theoretically, this is possible. However, if i would develop such a framework, i would surely want to implement CSS3 which features styling and skinning mechanisms that imho beat those implemented in all current GUI toolkits together, and integrates perfectly into all mentioned W3C technologies. So depending on what toolkit you use, you probably can only implement a subset of CSS3. I also think that it wouldn’t be very easy to integrate custom component sets, or rather, i think it wouldn’t be worth the pain.

C64 Emulator for Flash Player 9

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I’m happy to finally be able to let the cat out of the bag. Darron Schall and myself have been working on a low level 6502/6510 emulator and, based on that, on a Commodore C64 emulator/simulator.

The emulator is completely written in Actionscript 3 and runs on Flash Player 9. It loads the original binary C64 Kernel ROMs at runtime, and executes them just like the original hardware would do.

The sources are released under GPL, get them here:
Trac: https://mirror1.cvsdude.com/trac/osflash/fc64/
SVN: http://svn1.cvsdude.com/osflash/fc64/

Quoting Darrons blog post from today:

It’s still a work in progress, and we’re looking for hardware-nerds to step up to the plate and help us finish it. The CPU code is complete, but hasn’t been extensively tested. The memory code is a work in progress, and we haven’t had a chance to start on the display code yet. Still though, it’s a good start.

At this point, we’re just running the CPU as fast as possible without trying to get the timing completely accurate. On the debug Flash Player, it runs at ~2.5 MHz. On the release Flash Player, it runs at closer to 6 or 7 MHz. This is a good thing, as the original Commodore chip only runs at 1 MHz. So, in theory, it should be possible to emulate the games in real-time without any slow down or speed delays (holy @#!@).

DENG and OpenLaszlo

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Inspired by a user i wrote a proof of concept DENG proxy today, to be used in OpenLaszlo applications.

Follow these steps:

  1. Download and install OpenLaszlo
  2. Create a folder “deng” in your my-apps folder ([openlaszlo]/Server/lps-3.1.1/my-apps)
  3. Download the DENG test application for OpenLaszlo and extract it into the folder you just created
  4. Point your browser to http://localhost:8080/lps-3.1.1/my-apps/deng/deng.lzx

You should get a minimal application with buttons to load two test documents and to set the size of the rendered documents:

OpenLaszlo & DENG test application

I must admit i’m a OpenLaszlo newbie (installed it today for the first time), and the solution smells a bit like a hack (it certainly is). I also have no idea yet how to send events from DENG to the OpenLaszlo app. Any pointers highly apprechiated!

AS3: Loading Class Libraries at Runtime

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The Flash Player 8.5 features a nifty API to dynamically load assets at runtime, using the flash.display.Loader and flash.system.ApplicationDomain classes. Let’s assume we have a package, test.c1, that we want to keep in a separate SWF and only load it into the main SWF when needed.

We create a project Main that has the following structure:

  • Main.as
  • Child1.as
  • test/c1/TestClass.as

Child1.as is compiled into Child1.swf and contains test.c1.TestClass.

Main.as is our main application class that loads Child1.swf and uses test.c1.TestClass.

test/c1/TestClass.as

package test.c1
{
   public class TestClass
   {
      public function TestClass() { }

      public function method():String {
         return 'test.c1.TestClass.method()';
      }
   }
}

Child1.as

package
{
   import flash.display.Sprite;
   import test.c1.TestClass;

   public class Child1 extends Sprite
   {
      public var TestClassInst:TestClass;

      public function Child1() { }
   }
}

Main.as

package
{
   import flash.display.Sprite;
   import flash.display.Loader;
   import flash.system.ApplicationDomain;
   import flash.net.URLRequest;
   import flash.events.*;
   import flash.util.trace;

   public class Main extends Sprite
   {
      private var child1:Loader;
		
      public function Main()
      {
         var url1:URLRequest = new URLRequest('Child1.swf');
         url1.applicationDomain = new ApplicationDomain(ApplicationDomain.currentDomain);

         child1 = new Loader();
         child1.addEventListener(EventType.COMPLETE, onChild1Complete);
         child1.load(url1);
      }

      private function onChild1Complete(e:Event):Void {
         trace('onChild1Complete ' + e);
         var c:Class = child1.loadeeInfo.applicationDomain.getClass('test.c1.TestClass');
         var co:Object = new c();
         trace('test.c1.TestClass.method() returns: ' + co.method());
      }
   }
}

Using this method we could have different implementations of an API in different SWFs, and load the one we need at runtime. Naturally, we would want to use interfaces to ensure the API implements the right things, and use those interfaces for both the external modules and the main app. Note that i instantiate test.c1.TestClass as an anonymous object in the above example (var co:Object = new c();). I actually should have provided an interface definition test.ITestClass that describes the features of that external class (var co:ITestClass = new c();), however the alpha of Flex Builder has a bug that currently prevents us from doing so. Macromedia is aware of that bug so hopefully this is fixed soon.

Flash Player 8.5 Alpha and GIS

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This weekend i continued to play with Flash Player 8.5 alpha, and did something kinda crazy (at least i thought so when i started).. I tried to render high resolution GIS data purely clientside with Flash.

In the beginning, i was just searching for detailed, free, redistributable map data of the world, with political country boundaries, and maybe state boundaries too, to write a simple world map component. I was scanning through a lot of link lists, and almost all material i found was either incomplete, not detailed enough or expensive. Except the “Vector Smart Map Level 0 Library”, a huge (1.8GB), free and redistributable collection of all sorts of high detailed geographic data, published by the National Imagery and Mapping Agency (NIMA).

“Published by the National Imagery and Mapping Agency (NIMA) on CD-ROM, the VMap0 database is designed to provide vector-based geospatial data at low resolution. The content of the database is similar to the previously published Digital Chart of the World, augmented with low resolution bathymetry for global coverage. A reference library with general information to orient the user and an index of geographic names to aid in locating areas of interest are provided. Data are separated into thematic layers: boundaries, elevation, hydrography, industry, physiography, population, transportation, utilities, and vegetation.

VMap0’s world coverage is divided into four libraries based on geographic areas. The geographic areas and library names, by disc, are:

* Disc 1 – North America (NOAMER)
* Disc 2 – Europe and North Asia (EURNASIA)
* Disc 3 – South America, Africa, and Antarctic (SOAMAFR)
* Disc 4 – South Asia and Australia (SASAUS)

The primary source for the database is the 1:1,000,000-scale Operation Navigation Chart (ONC) series co-produced by the military mapping authorities of Australia, Canada, United Kingdom, and the United States. Data gaps may exist where source information is not available.”

But how to get this data into the Flash Player? The format they use is VPF (Vector Product Format, [PDF]), a heavily cross linked, binary format. I started reading through the spec, and thought that with the capabilities of the new Flash Player 8.5 alpha (highly increased VM performance), it could actually work to just load the data as is and render it. Said and done.

Here’s a proof of concept application i threw together over the weekend, that loads the “Library Reference” coverage (3MB, binary, as is, using the new URLStream class), deserializes the data into Arrays, and renders the data on screen while loading. What we get is a quite detailed map of the world with country-level political boundaries.

http://codeazur.com.br/stuff/flex2/vmap0/
Note: Flash Player 8.5 alpha required! (Get it here)

For those of you who don’t have the alpha player installed, here is a screenshot:
Vector map of the world, global view

And here’s another, fully zoomed in to Japan:
Vector map of the world, Japan (zoomed)

The Flash Player renders the whole map in around 5 seconds (delayed with enterframe events) on my machine, drawing 250.000 lines in more than 2.000 shapes.

The only drawback: it takes a while until the data is loaded (depends on your connectivity of course).

FP 8.5: Tooltips over links in HTML enabled TextFields

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If you move your mouse pointer over a hyperlink in an HTML webpage, your browser typically displays the URL in it’s status bar. In addition, if the hyperlink has a title attribute set, a tooltip is shown with a human readable description of the linked resource.

Unfortunately, with rich text used in Flash websites/applications this is not the case. Your mouse pointer will change to a “hand-cursor”, indicating you’re hovering a hyperlink, but the status bar will stay empty, and the title attribute is ignored by Flash, making it impossible for you to find out where the hyperlink will take you without actually clicking it.

With Flash Player 8.5 alpha, the behaviour of hyperlinks in rich text controls hasn’t changed (yet?), but luckily Macromedia implemented some nifty API extensions making it possible to actually find out if the user is hovering a hyperlink in a HTML enabled TextField.

Here’s how it works:

FP 8.5 introduces the TextField.getCharIndexAtPoint(x, y) method, returning the index of the character in a TextField at the point (x, y).

You can then get the TextFormat of the character at that index, using TextField.getTextFormat(i, i+1), and check it’s url property. If set, display it in a Tooltip, or send it to Javascript via ExternalInterface to show it in the browser’s status bar. Done.

Demo:

http://codeazur.com.br/stuff/flex2/OnHoverApp.html (FP 8.5 required)
http://codeazur.com.br/stuff/flex2/OnHoverApp.zip (Sources)

In this demo i subclassed the Flex 2 component mx.controls.Text and use it via MXML, however you can as well use this method with normal TextFields in your Actionscript 3 projects.

Flash Player 8.5 – SPEED!

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You heard the news already, Macromedia launched their Labs site today, along with public alphas of Flash Player 8.5, Flex Builder 2 and the Flex Framework 2.

Among the first things i did with those alpha goodies was porting the DENG CSS 3 parser to Actionscript 3.

Results of first benchmark (Parsing a 20kb CSS file into an object DOM):

  • AS2, Flash Player 8: around 1000ms
  • AS3, Flash Player 8.5: around 80ms

That’s a 12.5x performance boost, without FP8.5 specific optimizations.
Flash is fun again!

I’m going to prepare a live demo of the parser in the next days for you to play with it.