Flex Frameworks

Luke Bayes and Ali Mills of PatternPark made a presentation for the Silicon Valley Flex Users Group (SilvaFUG) of 9 different frameworks and toolkits for creating Flex applications: Cairngorm, PureMVC, ARP, MVCS, Flest, Model-Glue: Flex, ServerBox Foundry, Guasax, and Slide.

Watch the presentation: http://adobechats.adobe.acrobat.com/p12266504/
See the slides: http://www.asserttrue.com/files/ApplicationFrameworks/index.html

Their Conclusion?
PureMVC by Cliff Hall beats out the alternatives

  • Composition over inheritence
  • Liberal use of Interfaces
  • Indirection is used but not overwhelming
  • Instance members hide singleton references from application code
  • MXML views can be extremely thin
  • Benefits of Cairngorm, with few of the disadvantages.

I must admit I never used PureMVC, the only framework I’m currently using is Cairngorm, even if I bookmarked the pureMVC page long time ago promising myself to watch it more in deep. Now it’s time to keep the promise.

AMFPHP and mbstring

These days I was working on a flex 2/amfphp project and I discovered a very strange issue accidentally.
With PHP 5.2.4 installed both on local and remote server, the local amfphp works and the remote gave errors.

Connecting to the service browser I was receiving the error “Channel.Ping.Failed” error and investingating a bit more in the fault message I discovered that the source error was:

The class {Amf3Broker} could not be found under the class path {/var/htdocs/amfphp/services/amfphp/Amf3Broker.php}

and the Amf3Broker php class does not exists anywhere in amfphp! But in the Actions.php file on line 78 I found this:
$uriclasspath = "amfphp/Amf3Broker.php";
$classpath = $baseClassPath . "amfphp/Amf3Broker.php";
$classname = "Amf3Broker";
$methodname = "handleMessage";

That’s the strange thing because the $handled variable should be true ’cause usually the first request sent by flash is a $messageType = “flex.messaging.messages.CommandMessage”. So I continued in my investigation logging all the messages that php was receiving.
So at the end I discovered that amfphp didn’t deserialize the amf data correctly! All the packet were corrupted (that’s why $messageType wasn’t handled), all the strings were not correctly parsed.
Finally I discovered the reason. It’s because mbstring.
The only difference between the remote server and the local server is the php.ini setting about mbstring overload and the others mbstring settings.
The remote server has mbstring.func_overload = 2, that means all the strings functions are affected and that’s why the amfphp methods were returing corrupted data.
In fact I just changed this method into AMFDeserializer.php:
function readBuffer($len)
$data = substr($this->raw_data,$this->current_byte,$len);
$this->current_byte += $len;
return $data;

function readBuffer($len)
$data = "";
for($i = 0; $i < $len; $i++) { $data .= $this->raw_data{$i + $this->current_byte};
$this->current_byte += $len;
return $data;

and the original error disappeared! Obviously I got other errors later, that’s because there are many other string functions in amfphp.. but at least I found the cause.

In fact, removing the mbstring.func_overload in the php.ini everything worked again!

Adobe Image Foundation

Everyone already knows about the new Flash player 10 (Astro) features that adobe presented at MAX, and above all the new image processing language (Hydra) that it will support in the future.

Today I finally found a couple of hours to play with AIF, even if no more because of my limitations knowledge of image processing algorithms 🙂
In fact I was able to broke different times my video card driver (with a panic black screen)!

Anyway after all I did just a couple of experiments trying to convert a couple of scripts I already did using the old flash 9 bitmapdata filters..

kernel Snn
parameter float size
< minValue: 0.0; maxValue: 8.0; defaultValue: 2.0; >;
parameter int step
< minValue: 1; maxValue: 10; defaultValue: 1; >;
void evaluatePixel(in image4 src, out pixel4 result)
pixel2 coord = outCoord();
pixel4 valueC = sampleLinear(src, coord);
float theStep = float(step);
float2 point = float2(0.0,0.0);
float x = 0.0;
float y = 0.0;
float count = 0.0;
pixel4 sum = pixel4(0.0, 0.0, 0.0, 0.0);
pixel4 valueA;
pixel4 valueB;
for( x = - size; x < size; x+= theStep)
for(y = -size; y < size; y+= theStep)
valueA = sampleLinear(src, pixel2(coord.x + x, coord.y + y));
valueB = sampleLinear(src, pixel2(coord.x - x, coord.y - y));
if ( any(lessThan(abs(valueC - valueA), abs(valueC - valueB))))
sum = sum + valueA;
} else {
sum = sum + valueB;
count = count + 1.0;
result = sum/count;

kernel Websafe
parameter float value
< minValue: 0.0; maxValue: 500.0; defaultValue: 10.0; >;
void evaluatePixel( in image4 src, out pixel4 result)
result = sampleLinear(src, outCoord());
result = (floor((result*255.0)/51.0) * 51.0)/255.0;

As you can see it’s nothing new, they’re just my first steps in this new language.. don’t spend much time on these example, look at the coolest examples shown in the Hydra gallery instead!

Microsoft to release .NET libraries source code

Well, it seems that Microsoft will release the .NET libraries (not all, but it seems the most relevants ) source code with the next release of Visual Studio 2008 late this year.

This will be useful indeed while debugging in VS, but also it would be very interesting to look into the source code to view how they did it, expecially the Windows Form related part.. (..but what about Silverlight? :))

Read more here: http://weblogs.asp.net/scottgu/…framework-libraries.aspx