Save and Load PDF in my App - swift

Question

I am downloading a .PDF file from a URL into a webview. It works fine , but because the pdf get updated mid month. I would like to download that file on the first of every month into my app, then the rest of the month load that saved file from the app rather than the web. Thank you for any help. I am using Swift.
following is my code so far :
import UIKit
import Social
// var justOnceThree:Bool = true
class KeyPagesViewController: UIViewController {
#IBOutlet weak var photoButton: UIButton!
#IBOutlet weak var baseKeypagesLabel: UILabel!
#IBOutlet weak var titleLabel: UILabel!
#IBOutlet weak var keyPages: UIWebView!
var urlFra = "http://someURL.pdf"
var urlLhr = "http://someURL.pdf"
let requestURL = NSURL()
override func viewDidAppear(animated: Bool) {
PhotoButton()
}
override func viewDidLoad() {
super.viewDidLoad()
animationtitle()
let sharedDefaults = NSUserDefaults(suiteName: "group.birkyboy.TodayExtensionSharingDefaults")
var based = sharedDefaults!.objectForKey("base") as? String
if based == "HNL" {
let requestURL = NSURL(string:self.urlHnl)
let request = NSURLRequest(URL: requestURL!)
UIApplication.sharedApplication().networkActivityIndicatorVisible = true
self.keyPages.hidden = false
self.keyPages.loadRequest(request)
self.baseKeypagesLabel.text = "HONOLULU"
}
if based == "IAH" {
let requestURL = NSURL(string:self.urlIah)
let request = NSURLRequest(URL: requestURL!)
UIApplication.sharedApplication().networkActivityIndicatorVisible = true
self.keyPages.hidden = false
self.keyPages.loadRequest(request)
self.baseKeypagesLabel.text = "HOUSTON"
}
}

Answer 1

You can save the PDF in the users Documents folder. See "iOS Standard Directories: Where Files Reside" in the Apple documentation. There are various ways to get the PDF from a URL. See NSInputStream for one way to do it. Once you have it (as an NSData object, for example), you can save it as a file.