AS3 multiple file download, check when completed? - actionscript-3

Question

I am looping through a small array of file names to grab from a remote server and save locally. This bit works OK.
The problem is, I need to run my next function when the downloads are complete.
Currently, my function, lets call it step2(), gets called before all the FileStreams can finish (infact, its called before that function even starts!)
I read that there is a complete event listener when using openAsynch, but I need to check that all files, e.g. 3 remote swfs) have been written and then start step2() function.
How can I go about this?
Code below:
function onPlaylistComplete(e:Event)
{
var myArray:Array = new Array();
for each(var i in list_of_files)
{
myArray.push(i);
}
for(i = 0; i < myArray.length; i++)
{
swfItem = myArray[i];
var urlString:String = site_url + myArray[i];
var urlReq:URLRequest = new URLRequest(urlString);
var urlStream:URLStream = new URLStream();
urlStream.addEventListener(Event.COMPLETE, urlStreamComplete(swfItem));
urlStream.load(urlReq);
}
function urlStreamComplete(swfItem):Function
{
var downloadSwf:Function = function (event:Event):void {
var fileData:ByteArray = new ByteArray();
var stream = event.target;
stream.readBytes(fileData, 0, stream.bytesAvailable);
try {
var f : File = File.documentsDirectory.resolvePath(swfItem);
var fs : FileStream = new FileStream();
fs.addEventListener(Event.COMPLETE, fileCompleteHandler);
fs.openAsync(f, FileMode.WRITE);
fs.writeBytes(fileData);
}
catch (err : Error) {
trace(err.message);
}
}
return downloadSwf;
}
function fileCompleteHandler(e:Event):void {
e.target.close();
}
step2(); // this seems to run before UrlStreamComplete()
}

Answer 1

Problem with your for loop it will never work with Async model. so better need work to with recursive function.
downloadAllFiles method second arg that is function called when all download are completed.Then you can call step2() or whatever may be.
Make sure if any problem while download file like IOErrorEvent,etc...
downloadAllFiles(myArray,function():void
{
step2();
});
function downloadAllFiles(myArray:Array, complete:Function):void
{
if(myArray && myArray.length == 0)
{
if(complete)
complete.call();
return;
}
swfItem = myArray.shift();
var urlString:String = site_url + swfItem;
var urlReq:URLRequest = new URLRequest(urlString);
var urlStream:URLStream = new URLStream();
urlStream.addEventListener(Event.COMPLETE, function (event:Event):void
{
var fileData:ByteArray = new ByteArray();
var stream = event.target;
stream.readBytes(fileData, 0, stream.bytesAvailable);
try {
var f : File = File.documentsDirectory.resolvePath(swfItem);
var fs : FileStream = new FileStream();
fs.addEventListener(Event.CLOSE, function(closeEvent:Event):void
{
downloadAllFiles(myArray,complete);
return;
});
fs.openAsync(f, FileMode.WRITE);
fs.writeBytes(fileData);
}
catch (err : Error)
{
trace(err.message);
}
});
urlStream.load(urlReq);
}

Answer 2

Can't you just move step2(); at the end of fileCompleteHandler function?
Because at this point step2(); is called right after going through for(i = 0; i < myArray.length; i++)
loop (Which is way to early).

Answer 3

What you are missing is a way to check that all files from your list are loaded, 3vliguy is right and your step2(); should be in the complete handler but, not alone, you have to also test if ALL files are loaded. you can do it in various ways, e.g. use file counter and when it is 0 (all files loaded) you will execute step2() else you will ignore it and just decrease counter.
p.s. the Raja Jaganathan way will work as well, only it is queued loading whereas with the counter you can start loading of all files at the beginning.