SWIFT GISTs

=== SWIFT GISTs

# Swift useful and common gists 

AccesToAppDelegate.swift

(UIApplication.sharedApplication().delegate as! AppDelegate)

HideStatusbar.swift

//Hide Statusbar
override func prefersStatusBarHidden() -> Bool {
    return true
}

Move View with Keyboard.swift

override func viewWillAppear(animated: Bool) {
    super.viewWillAppear(animated)
    //Suscribe Notification
    NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillShow:", name: UIKeyboardWillShowNotification, object: nil)
}
override func viewWillDisappear(animated: Bool) {
    super.viewWillDisappear(animated)
    //Unsuscribe Notification
    NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillShowNotification, object: nil)
}

func getKeyboardHeight(notification: NSNotification) -> CGFloat{
    let userInfo = notification.userInfo
    //of CGRect
    let keyboardSize = userInfo![UIKeyboardFrameEndUserInfoKey] as! NSValue
    return keyboardSize.CGRectValue().height
}
func keyboardWillShow(notification: NSNotification){
    view.frame.origin.y -= getKeyboardHeight(notification)
}

NSURLSession.swift

func getImage(){
        //https://developer.apple.com/library/ios/documentation/Foundation/Reference/NSURLSession_class/
        let imageUrl = NSURL(string: "https://upload.wikimedia.org/wikipedia/commons/4/4d/Cat_November_2010-1a.jpg")!
        let task = NSURLSession.sharedSession().dataTaskWithURL(imageUrl) { (data, response, error) in
            if nil == error {
                let downloadedImage = UIImage(data: data!)
                performUIUpdatesOnMain({
                    self.imageView.image = downloadedImage
                })
            }else{
                print("error",error)
            }
        }
        //It starts the request
        task.resume()
}

NSURLSessionAdvancedJSON.swift

func getJson(){
        let url = NSURL(string: "https://somjsonurl.com")!
        let request = NSURLRequest(URL: url)
        //We can change the method (GET/POST) using NSMutableURLRequest
        let task = session.dataTaskWithRequest(request) { (data, response, error) in
            // if an error occurs, print it and re-enable the UI
            func displayError(error: String) {
                print(error)
                performUIUpdatesOnMain {
                    self.setUIEnabled(true)
                    self.photoTitleLabel.text = "No photo returned. Try again."
                    self.photoImageView.image = nil
                }
            }
            
            /* GUARD: Was there an error? */
            guard (error == nil) else {
                displayError("There was an error with your request: \(error)")
                return
            }
            
            /* GUARD: Did we get a successful 2XX response? */
            guard let statusCode = (response as? NSHTTPURLResponse)?.statusCode where statusCode >= 200 && statusCode <= 299 else {
                displayError("Your request returned a status code other than 2xx!")
                return
            }
            
            /* GUARD: Was there any data returned? */
            guard let data = data else {
                displayError("No data was returned by the request!")
                return
            }
            
            // parse the data
            let parsedResult: AnyObject!
            do {
                parsedResult = try NSJSONSerialization.JSONObjectWithData(data, options: .AllowFragments)
            } catch {
                displayError("Could not parse the data as JSON: '\(data)'")
                return
            }
            
            
            guard let stat = parsedResult["someKey"] as? String where stat == "ok" else {
                displayError("API ERROR \(parsedResult)")
                return
            }
        }
        //It starts the request
        task.resume()
}

//AUX
//Create safe URLS
func urlFromParameters(parameters: [String:AnyObject]) -> NSURL {
        
        let components = NSURLComponents()
        components.scheme = Constants.APIScheme
        components.host = Constants.APIHost
        components.path = Constants.APIPath
        components.queryItems = [NSURLQueryItem]()
        
        for (key, value) in parameters {
            let queryItem = NSURLQueryItem(name: key, value: "\(value)")
            components.queryItems!.append(queryItem)
        }
        
        return components.URL!
    }

NSUserDefaults.swift

func saveAValue() {
    let defaults = NSUserDefaults.standardUserDefaults()

    // Save a float value into the defaults, using the key "myValue"
    defaults.setFloat(22.5, forKey: "myValue")
}

func readAValue() {
    // Read the current value for the "myValue" key
    let defaults = NSUserDefaults.standardUserDefaults()
    theValue = defaults.floatForKey("myValue")
    ...
}

presentViewController.swift

//
    //Select Image
    @IBAction func actionPicker(sender: AnyObject) {
        let nextController = UIImagePickerController()
        presentViewController(nextController, animated: true, completion: nil)
    }
    //Share
    @IBAction func actionActivity(sender: AnyObject) {
        let image = UIImage()
        let nextController = UIActivityViewController(activityItems: [image], applicationActivities: nil)
        presentViewController(nextController, animated: true, completion: nil)
    }
    //Show alert
    @IBAction func actionAlert(sender: AnyObject) {
        let nextController = UIAlertController()
        let okAction = UIAlertAction(title: "ok", style: UIAlertActionStyle.Default){ action in
            self.dismissViewControllerAnimated(true, completion: nil)
            }
        nextController.addAction(okAction)
        presentViewController(nextController, animated: true, completion: nil)
    }
    
    //Custom View Controller
     @IBAction func showCustomView() {
        var controller: CustomViewController
        controller = self.storyboard?.instantiateViewControllerWithIdentifier("CustomViewControllerIdentifier") as! CustomViewController
        presentViewController(controller, animated: true, completion: nil)
    }

pullToRefresh.swift

var refreshControl: UIRefreshControl!

override func viewDidLoad() {
   super.viewDidLoad()

   refreshControl = UIRefreshControl()
   refreshControl.attributedTitle = NSAttributedString(string: "Pull to refresh")
   refreshControl.addTarget(self, action: Selector("refreshTable:"), forControlEvents: UIControlEvents.ValueChanged)
   tableView.addSubview(refreshControl)
}

func refreshTable(sender:AnyObject) {
   // refresh table
}

//end refreshing after 
//refreshControl.endRefreshing()

UIActivityViewController Share.swift

let viewController = UIActivityViewController(activityItems: [img], applicationActivities: [])
presentViewController(viewController, animated: true, completion: nil)

UICollectionViewDataSource.swift

    //Don't forget set the 
    @IBOutlet weak var collection: UICollectionView!
    override func viewDidLoad() {
        super.viewDidLoad()
        //It can be setted in the StoryBoard
        collection.dataSource = self
        collection.delegate = self
        
    }
    //MARK: Collection
    func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return array.count
    }
    func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
        let cell = collection.dequeueReusableCellWithReuseIdentifier("someCollectionCell", forIndexPath: indexPath) as! CollectionMemeCollectionViewCell
        cell.imgView.image = array[indexPath.row].img
        return cell
    }
    func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
        collection.deselectItemAtIndexPath(indexPath, animated: true)
        //PerformSegue?
    }

UICollectionViewFlowLayout.swift

//Set The size for each collection view cell
@IBOutlet weak var flowLayout: UICollectionViewFlowLayout!
override func viewDidLoad() {
  super.viewDidLoad()
  initFlowLayout()
}
func initFlowLayout() {
  let space:CGFloat = 3.0
  let dimension = (self.view.frame.size.width - ( 2 * space )) / 3.0
  flowLayout.minimumInteritemSpacing = space
  flowLayout.minimumLineSpacing = space
  flowLayout.itemSize = CGSizeMake(dimension, dimension*1.5)
 }

UIGestureRecognizer.swift

    //MARK: Gestures
    func gestureRecognizer(_: UIGestureRecognizer,
        shouldRecognizeSimultaneouslyWithGestureRecognizer:UIGestureRecognizer) -> Bool {
            return true
    }
    @IBAction func actionGesturePinch(sender: UIPinchGestureRecognizer) {
        if let view = sender.view {
            view.transform = CGAffineTransformScale(view.transform,
                sender.scale, sender.scale)
            sender.scale = 1
        }
    }
    @IBAction func actionGestureRotate(sender : UIRotationGestureRecognizer) {
        if let view = sender.view {
            view.transform = CGAffineTransformRotate(view.transform, sender.rotation)
            sender.rotation = 0
        }
    }
    func resetScaleAndRotation(){
        imgChoosed.transform = CGAffineTransformScale(view.transform,
            1, 1)
        imgChoosed.transform = CGAffineTransformRotate(view.transform, 0)
    }

UIImagePickerController.swift

UIImagePickerController *picker = [[UIImagePickerController alloc] init];
        picker.delegate = self;
        picker.allowsEditing = NO;
        picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;


-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info{
    UIImage *chosenImage = info[UIImagePickerControllerOriginalImage];
    self.imageView.image = chosenImage;
    [picker dismissViewControllerAnimated:YES completion:nil];
}