How to continue Alamofire Download task after suspend it, terminate the app, and reopen the app - alamofire

Question

I need to write a downloader for my app, and It can pause, continue and cancel the downloads. Also it must support to pause download, kill the app, and reopen the app and continue from where it paused.
How can i keep the downloaded data and how can I continue it?
import UIKit
import Foundation
import Alamofire
class DownloaderViewController: UIViewController {
#IBOutlet weak var label: UILabel!
let progressIndicatorView = UIProgressView()
var request: Alamofire.Request?
override func viewDidLoad() {
super.viewDidLoad()
}
}
#IBAction func cancelBtn(sender: AnyObject) {
self.request?.cancel()
self.label.text = "% 0.0"
}
#IBAction func pauseBtn(sender: AnyObject) {
self.request?.suspend()
}
#IBAction func continueBtn(sender: AnyObject) {
self.request?.resume()
}
#IBAction func startBtn(sender: AnyObject) {
var localPath: NSURL?
self.request = Alamofire.download(.GET, "https://dl.dropboxusercontent.com/u/11563257/3.%20Interactive_iPad_test_for_PDF_EXPERT.pdf", destination: { (temporaryURL, response) in
let directoryURL = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)[0]
let pathComponent = response.suggestedFilename
localPath = directoryURL.URLByAppendingPathComponent(pathComponent!)
return localPath!
}).progress() {
(_, totalBytesRead, totalBytesExpectedToRead) in
dispatch_async(dispatch_get_main_queue()) {
self.progressIndicatorView.setProgress(Float(totalBytesRead) / Float(totalBytesExpectedToRead), animated: true)
self.updateProgress(self.progressIndicatorView)
if totalBytesRead == totalBytesExpectedToRead {
self.progressIndicatorView.removeFromSuperview()
}
}
}
func updateProgress(prg:UIProgressView) {
let stepSize:Float = 0.1
prg.setProgress(prg.progress + stepSize, animated: true)
self.label.text = "% " + String(format: "%.2f", prg.progress*100)
}
}
This works while the app is running. But I need to save the data when the app is terminated and continue it when the app started. I have no i idea how to keep the downloaded data and how to continue it. Any help will be appriciated.

Answer 1

I find this in Alamofire documentation :
Alamofire.download(.GET, "https://httpbin.org/stream/100", destination: destination)
.response { _, _, data, _ in
if let
data = data,
resumeDataString = NSString(data: data, encoding: NSUTF8StringEncoding)
{
print("Resume Data: \(resumeDataString)")
} else {
print("Resume Data was empty")
}
}
But I get "Resume Data was empty" everytime. I give the same destination. But It can't catct the Resume Data. And I couldn't find an example with Alamofire.