downloadRequest = Alamofire.download(.GET, urlString!, destination: { [weak self](temporaryURL, response) -> NSURL in
let fileManager = NSFileManager.defaultManager()
let directoryURL = fileManager.URLsForDirectory(NSSearchPathDirectory.DocumentDirectory, inDomains: NSSearchPathDomainMask.UserDomainMask)[0]
let pathComponent = "imageFile/" + response.suggestedFilename!
self?.destination = NSHomeDirectory() + "/Documents/" + pathComponent
return directoryURL.URLByAppendingPathComponent(pathComponent)
})