In the case where you want to proxy calls to vararg methods you have to use the Function#apply() method.

var array:Array = [];
var stuffToAdd:Array = [ 1, 2, 3, 4 ];
 
array.push.apply(array, stuffToAdd);

It would be nice to have a splat/unpack operator:

array.push(*stuffToAdd);
// Or
array.push(... stuffToAdd);

The ecma mailing list discussed this use of super.apply(this, arguments). And specifically regarding argument unpacking in AS3:

We dropped this from AS3 for lack of evidence for its need.

I think any language with (... args) to Array needs the Array to (... args) if not for anything other than completeness. Does anyone know if this is planned for ES4 at least?

This is a follow-up to a previous post.

This issue does not arise when using the new File api (and writing to
files), since an event has been included in
flash.filesystem.FileStream: OutputProgressEvent.OUTPUT_PROGRESS

If this (or a similar) event could be added to the Socket api, it
would allow us to:

• Send large amounts of data on a socket (without causing large memory
  usage as data buffers in memory).
• Measure the current progress of data being sent on the socket.

We came upon this limitation from using our AS3 http client library, and trying to send large
files as part of a multipart upload. However this issue would arise
when sending any significant amounts of data on a socket. For example, an FTP or bittorrent client would be impossible.

This issue has been discussed in other places, but is probably more
pressing now with the AIR releases.

• Getting progress events on Socket *write* (not read)
• FlexFTP – FTP Client in Flex using flash.net.Socket (see comment by mailboo)

Update: Vote on this bug (FP-6)

I thought I would try to experiment with the different proposals and compare to languages I am using right now. I picked something simple to try out, like summing an array of integers:

Also check out good closures, bad closures.

Actionscript 3

Assume you have a reduce function, for example:

public function reduce(array:Array, f:Function, index:int = 0):* {
  if (index == array.length - 1) return array[index];
  return f(array[index], reduce(array, f, index + 1));
}

Then the syntax is:

var array:Array = [ 1, 2, 3 ];
reduce(array, function(x1:Number, x2:Number):Number { return x1 + x2; });

Ruby

Sorry I have to.

array = [ 1, 2, 3 ];
array.inject { |sum, n| sum + n }

or with Symbol#to_proc:

array = [ 1, 2, 3 ];
array.inject(&:+)

Java (CICE)

Assume you have a “Reducer” interface (and Collections#reduce):

interface Reducer<T> {
  T reduce(T t1, T t2);
}

List<Integer> = Arrays.asList([ 1, 2, 3 ]);
Integer sum = Collections.reduce(list, Reducer<Integer>(Integer x1, Integer x2) {
  return x1 + x2;
});

I think this is right, help? So you might have to declare new interfaces if the API doesn’t have them. It would probably have common ones though.

Java (BGGA)

Assume you have Collections#reduce:

List<Integer> = Arrays.asList([ 1, 2, 3 ]);
Integer sum = Collections.reduce(list, { Integer x, Integer y => x+y });

The other powerful thing with the BGGA proposal is the control invocations, like:

Lock lock = new Lock();
 
Lock.withLock(lock) {
  doSomething();
}
 
// Automatically close stream when done
with(FileInputStream f : exp) {
  doSomething();
}

Like in Ruby:

mutex = Mutex.new
mutex.synchronize do
  doSomething
end
 
File.open("foo.txt", "w") do |file|
  doSomething
end

Since I’ve been doing Ruby lately, I know which Java proposal I prefer. The CICE doesn’t address the problem that within an anonymous inner instance return, and this and any anonymous instance methods are scoped to that anonymous instance and not the enclosing method.

I guess CICE is more about reducing the verbosity of the anonymous instance declaration and allowing mutability on public variables, and its not a real closure in the strict definition. I know people refer to anonymous inner classes as the poor man’s closure, but I don’t really think of it as a closure, I think of it as, you know, an anonymous inner class.

I got everything major working like GET, PUT and POST with multipart/form-data and reading chunked encoding and all that stuff. Not too hard since there are open source http libraries for every major language. I looked at ruby Net::HTTP (stole some regex’s) and Apache Httpclient (stole your multipart boundary).

I got to the point where I was testing uploading larger files, like in:

var client:HttpClient = new HttpClient();
var uri:URI = new URI("http://mybucket.s3.amazonaws.com/big.mp3");
var testFile:File = new File("app:/test/assets/big.mp3");
client.upload(uri, testFile);

It turns out that when you call _socket.flush() (in HttpSocket) it doesn’t actually block, which you might expect. After thinking on it, this isn’t totally shocking since the whole threading model behind actionscript, you don’t really ever block (like there is no such thing as a modal dialog in flash). The problem is without blocking or an event to notify of a flush, the socket just gets filled with the request body all at once (all 800MB’s or whatever file size).

It turns out other people ran into this as well. If you look at (FlexFTP) source, the UploadInv.as file, you will see block of code commented out and replaced by a setInterval(.. , 300). Nice. I guess that upload is capped at ~12kb/sec.

Any of the links in the comments off this blog post are useful too.

If you look at FileStream object you will see it has an outputProgressEvent so that would be useful, you know, if Socket had that too.

I don’t know how you get around this issue, other than trying to guess how fast the socket can transmit and try to stay under that. So now I’m not sure what to do, other than abandon it and come back to it when its fixed, which hopefully will be soon. Thankfully, I can go back to ruby and maybe play with some RubyCocoa or Shoes framework.

Update: Feel free to chime in at Adobe Air Forum or Feature Request/Bug Report Form

“AsProject automates a variety of tasks including the creation of projects, classes, test cases, test suites, and swfmill libraries. It automates the download, installation and configuration of the debug flash player and many open source tools. AsProject also includes sophisticated build tools written in rake to automate build processes.”

Video demo or Project page

gem install asproject

Also, a friend Corey pointed out that you can debug flash using Actionscript ExternalInterface to log to Firebug console.log instead of using ASUnit’s debug console. In your actionscript:

 ExternalInterface.call("console.log", "FLASH: " + s);

And make sure to allowScriptAccess.

1
2
3

var so = new SWFObject("flash/xxx.swf", "myswf", "680", "200", "8", "#FFFFFF");
 so.addParam("allowScriptAccess", "always");
 so.write("xxx");

And you could call any javascript from it. ExternalInterface is a replacement for fscommand. I don’t remember but I don’t think ExternalInterface works in all browsers.