iTunes has long been a closed platform and Adobe AIR is not designed to natively launch or interact with other applications except for the browser. I needed a solution to add MP3 files downloaded through an AIR application to iTunes or any other media player that the user may have installed.

Option 1…

Modifying the iTunes library XML file could potentially be done, but this has risks. Firstly, the XML file can get prohibitively big, and given AIR can only use the DOM method for parsing XML, it could crash the application and do untold damage to the XML library itself, which brings up the issue to backing up the library first. Also unknown is the behavior if iTunes tries to modify the library at the same time as the AIR application, not to mention the requirement to restart iTunes after the change to reflect the changes. All in all this was not a good option, with lengthy development, risky outcome and poor user experience.

Option 2…

iTunes has a COM api library accessible from a native java or .Net application, which in turn could be initiated by AIR. This is far from ideal due to having a second application running on the user’s computer, the volume of development effort to create the application and the complexity.

Option 3…

Users can commonly add songs to iTunes by dragging files into it. This is accompanied by the fact that iTunes launches when double-clicking on any file associated with it such as .mp4 or .mp3 and of course .m3u playlist files. By launching an m3u file with a collection of track paths contained within it, iTunes will launch, songs will be added to the library and user experience is not compromised and development is simple. Although AIR cannot natively launch iTunes, it can launch files, via the browser, thus launching any application that is associated with the file-type. m3u files are commonly associated with iTunes, but also windows media player and any other media player worthy of use.

The key area of development is to dynamically create m3u playlists before calling them with a URLRequest. This function uses Fzip to unzip any zip files that may have been downloaded and creates a collection of paths to write to the playlist file. The playlist data is stored in memory with each download item until the user decides to add the item.

private function generatePlaylist():void {
var playlistName:String = (tmpFile.name.split(’.'))[0]
var os:String = Capabilities.os.substr(0, 3).toLowerCase();

var playlistpath:String
if (os == “mac”) {
if (productType == “album”) {
playlistpath = unzip(File.desktopDirectory.resolvePath(tmpDownloadURL + artistPath + tmpFile.name.replace(”.tmp”,”")).url,File.desktopDirectory.resolvePath(tmpDownloadURL + artistPath).url);
} else {
playlistpath = viewableDownloadURL + artistPath + tmpFile.name.replace(”.tmp”,”");
}
} else {
if (productType == “album”) {
playlistpath = unzip(File.desktopDirectory.resolvePath(tmpDownloadURL + artistPath + tmpFile.name.replace(”.tmp”,”")).url,File.desktopDirectory.resolvePath(tmpDownloadURL + artistPath).url);
} else {
playlistpath = viewableDownloadURL + artistPath.replace(/\//g, “\\”) + tmpFile.name.replace(”.tmp”,”");
}
}
this.Playlist = playlistpath;
}

I kind of got into a mini pickle over forward slashes and back slashes that causes this function to be a little more complicated than is probably necessary, but you get the idea. Next it is necessary to create the playlist file and do the URLRequest after a button-click…

public function addToItunes(e:MouseEvent):void {
var playlistfile:File = File.applicationStorageDirectory.resolvePath(”playListCache/” + e.currentTarget.data[6] + “.m3u”);
var playliststream:FileStream = new FileStream();
var dlManager:DownloadManager;

for (var i:uint = 0; i < downloadManagerObjects.length; i++) {
dlManager = DownloadManager(downloadManagerObjects[i]);

if (e.currentTarget.data[2] == dlManager.FileID) {
playliststream.open(playlistfile, FileMode.WRITE);
playliststream.writeUTFBytes(dlManager.Playlist);
playliststream.close();
}
}
navigateToURL(new URLRequest(playlistfile.url), 'quote');
stage.nativeWindow.alwaysInFront = true;
stage.nativeWindow.alwaysInFront = false;
}

Notably I do a bit of mucking about with the stage to make sure the application stays in front when launching the URL through the browser.