Download multiple file without user interaction in flex web application possible? - actionscript-3

Question

Before asking question I says that read properly what is question.
I am creating web application for download videos files.
In which I am going to create functionality like. User select multiple file to download. The Video URL come from webservice.
Question:
Now, I need that when user click on Downloads then open new page which is in flex. Now, suppose there is 5 files to download, then it will start automatically to download first file. which shows progress of downloading.
Once Downloading Done of first file then start for Second file, then third and So on.
The files are download in default path of browser OR in specified of flex code. And file size may large. (More than 500 MB).
I search lot for it but, didn't get any proper solution. It says that it's not possible without user interaction.
But, If user interaction is required then user has to continuously watch to download that large file and then need action for download second file.
Is it possible using flex? If yes then How?
Any help will appreciate.
Thanks,

Answer 1

As you've stated the question it is not possible to do this.
From the web Flash Player you only have 2 options:
Use FileReference/save() which requires the user to choose where to save the file.
Use navigateToURL() to point the browser to the file location, which lets the browser decide how to handle the download -- immediately download it to the default download directory, or let the user choose. This isn't as reliable. (A variation of this is to use ExternalInterface to call JS window.open, which is the JS equivalent to navigateToURL.)
In either case you cannot choose where to download the file to from Flex, or even know where they do download it, and you can't use either of these options without user interaction (such as clicking a button).
Using AIR (desktop application) you can do this using File and FileStream.

Answer 2

Create a method to load your file (give a file path as parameters or use an Array or Vector with all respective urls). As soon as you finish the first download, check if there is more items in your array, and if so, load the subsequent index. It's not necessary that the user will need to have any interaction.
Example of loader with init, progress and complete states.
var myLoader:Loader = new Loader();
myLoader.contentLoaderInfo.addEventListener(Event.INIT, initListener);
myLoader.contentLoaderInfo.addEventListener(ProgressEvent.PROGRESS, progressListener);
myLoader.contentLoaderInfo.addEventListener(Event.COMPLETE, completeListener);
myLoader.load(new URLRequest("yourFile.png"));
function initListener(event:Event):void
{
// just started the loader process
trace("Object Initialized");
}
function progressListener (event:ProgressEvent):void
{
trace("Downloaded " + event.bytesLoaded + " out of " + event.bytesTotal + " bytes");
}
function completeListener(event:Event):void
{
// here you can load the next file
trace("Loading Completed");
}

Answer 3

For Flash player security reasons It's impossible to download a file in background mode without user interaction. I worked on something like what you are doing for a web tv project, where user can download a video and it's attached files (some hundreds), for that I used a server side PHP script which is called using navigateToURL() to download the video file and a zip which contain all attached files (the PHP script is called twice).
So, for that you can do :
PHP :
<?php
// some controls here
$file = $_GET['f'];
if (file_exists($file)) {
header('Content-Description: File Transfer');
header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename='.basename($file));
header('Expires: 0');
header('Cache-Control: must-revalidate');
header('Pragma: public');
header('Content-Length: '.filesize($file));
readfile($file);
exit();
}
?>
ActionScript :
const download_url:String = 'http://www.example.com/download.php?f=';
var files:Array = ['01.mp4', '02.mp4', '03.mp4', '04.mp4', '05.mp4'];
var index:int = 0;
var timer:Timer = new Timer(100, files.length);
timer.addEventListener(
TimerEvent.TIMER,
function(e:TimerEvent){
navigateToURL(new URLRequest(download_url + files[index]));
index ++;
}
)
timer.start();
Of course this code will download files via the browser as any file downloaded by user. Note here, that sometimes browser can block download because it's considered as a popup, so you have to mention that to your users to give your site permission to download files.
This code is just an example to show you a manner how to do what you want, may be you are not using PHP in your server, so you have to improve and adapt it to your specific needs.
Hope that can help.