Swift Save images (screenshots) to nsuserdefaults - swift

Question

I have a program, where the user "creates" an image, and then the program takes a screenshot of the screen. I would then like to save this screenshot to a database, prefferebly nsuserdefaults, since I am accessing it later in a table view. Any other suggestions on how to approach this, are more than welcome :)
The code is like this
let screenshot = getScreenshot() // saves the screenshot
var imagePaths = [String]()
// get the array of previous screenshots
if let _ = NSUserDefaults.standardUserDefaults().objectForKey(theKey)
{
imagePaths = NSUserDefaults.standardDefaults().objectForKey(theKey) as! [String]
}
// then I want to get a path to the image something like
let imagePath = screenshot.getPath() // although this is not a valid method, this is basically what I want
// add the imagePath
imagePaths.append(imagePath)
// finally I save the image
NSUserDefaults.standardUserDefaults().setObject(imagePaths, forKey: theKey)

Answer 1

You can create directory in Documents and save there screenshots as usual files. Filename can be generated from date and time for uniqueness.
func saveImage(imageData: NSData)
{
let dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "dd-MM-yyyy hh.mm.ss"
let filename = "\(dateFormatter.stringFromDate(NSDate())).png"
let documentsDirectory = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true).first as! String
let imagesDirectory = documentsDirectory.stringByAppendingPathComponent("Images")
let filePath = imagesDirectory.stringByAppendingPathComponent(filename)
if !NSFileManager.defaultManager().fileExistsAtPath(imagesDirectory)
{
var error: NSError?
NSFileManager.defaultManager().createDirectoryAtPath(imagesDirectory, withIntermediateDirectories: false, attributes: nil, error: &error)
if error != nil
{
println("\(error!.localizedDescription)")
return
}
}
imageData.writeToFile(filePath, atomically: true)
}
func getImagesPaths() -> [String]?
{
let documentsDirectory = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true).first as! String
let imagesDirectory = documentsDirectory.stringByAppendingPathComponent("Images")
if let filenames = NSFileManager.defaultManager().contentsOfDirectoryAtPath(imagesDirectory, error: nil)
{
let imagePaths = filenames.map{"\(imagesDirectory)/\($0)"}.filter(){$0.pathExtension == "png"}
return imagePaths.count > 0 ? imagePaths : nil
}
return nil
}
To save image simply use saveImage(data). To get images paths use getImagesPaths().
If you need array of UIImage, you can get it by follow way:
var images : [UIImage] = [ ]
if let imagePaths = getImagesPaths()
{
for path in imagePaths
{
if let image = UIImage(contentsOfFile: path)
{
images.append(image)
}
}
}