Adding ipod music files to bundles files in swift

Question

I am making an app that I want it to pick a song from the iPod music files then add it to the bundle files (documents folder) so that I can use it with the need to access the phones music list again.

I have managed to pick the song and get its ID but I don't know how to add a file to my bundles files using Swift.

I have found answers a bit similar to this question but its all since iOS 4 and using Objective C not Swift.

This is the code which has the files ID:

let u: NSURL? = 
        self.mediaItem!.valueForProperty(MPMediaItemPropertyAssetURL) as! NSURL?
if u == nil {
    return
}

Answer 1

The source of my answer is here, I didn't test the code:

func mediaPicker(mediaPicker: MPMediaPickerController, didPickMediaItems mediaItemCollection: MPMediaItemCollection) {
    let item: MPMediaItem = mediaItemCollection.items[0]
    let pathURL: NSURL? = item.valueForProperty(MPMediaItemPropertyAssetURL) as? NSURL
    if pathURL == nil {
        Alert.showPopupWithMessage("Unable to read DRM protected file.")
        return
    }

    // Export the ipod library as .m4a file to local directory for remote upload
    let exportSession = AVAssetExportSession(asset: AVAsset(URL: pathURL!), presetName: AVAssetExportPresetAppleM4A)
    exportSession?.shouldOptimizeForNetworkUse = true
    exportSession?.outputFileType = AVFileTypeAppleM4A
    let fileUrl = //Where you want to save the file
    exportSession?.outputURL = fileUrl
    exportSession?.exportAsynchronouslyWithCompletionHandler({ () -> Void in
        if exportSession!.status != AVAssetExportSessionStatus.Completed  {
            print("Export error")
        }
    })
}