iOSnippets

[iosnippets-blog]

Log with file name and location

Since Swift has lazy evaluation for __FUNCTION__, __ FILE__, __ LINE__, __ COLUMN__ identifiers (contrary to C macros, which are preprocessor definitions), we can use the safely for logging the call location of the *log* function.

func log(message: String,    function: String = __FUNCTION__,    file: String = __FILE__,    line: Int = __LINE__) {    let strippedFile = NSURL(fileURLWithPath: file).lastPathComponent    NSLog("\"\(message)\" - \(strippedFile!):\(line) - \(function)") }

[iosnippets-blog]

Disable Paste into UITextField

In case you need to disable the "Paste" operation, for security reasons for example, this is the class you're searching for:

class NoPasteField: UITextField {    override func canPerformAction(action: Selector, withSender sender: AnyObject?) -> Bool {        if action == "paste:" {            return false        }        return super.canPerformAction(action, withSender: sender)    } }

[iosnippets-blog]

Generate a Screenshot and share it to Facebook, email, message...

// Generate the screenshot         let layer = UIApplication.sharedApplication().keyWindow!.layer let scale = UIScreen.mainScreen().scale UIGraphicsBeginImageContextWithOptions(layer.frame.size, false, scale); layer.renderInContext(UIGraphicsGetCurrentContext()!) let screenshot = UIGraphicsGetImageFromCurrentImageContext() UIGraphicsEndImageContext() // Share let postImage = screenshot let textToShare = "Local weather" let vc = UIActivityViewController(activityItems: [textToShare, postImage!], applicationActivities: []) presentViewController(vc, animated: true, completion: nil)

[iosnippets-blog]

Text View Placeholder

By default UITextFielf doesn't have a placeholder property like UITextField, so it has to be manipulate programmatically.

First adopt UITextViewDelegate and then set the placeholder text in viewDidLoad:

messageTextView.delegate = self messageTextView.text = placeholderText messageTextView.textColor = UIColor.lightGrayColor()

Text View delegate methods:

var placeholderText = "Compose message" func textViewShouldBeginEditing(textView: UITextView) -> Bool {    if messageTextView.text == placeholderText        messageTextView.text = ""        messageTextView.textColor = UIColor.blackColor()    }    return true } func textViewShouldEndEditing(textView: UITextView) -> Bool {    if textView.text.isEmpty {        messageTextView.text = placeholderText        messageTextView.textColor = UIColor.lightGrayColor()    }    return true }

[iosnippets-blog]

Sliding Menu

This is an example of simple Sliding Navigation Menu build without using an external library.

In the Storyboard add a UIViewController that holds two Container Views:

UITableViewController for the Menu options - 80% of the screen width and

Tab Bar Controller that holds the selected menu details - 20% of the screen width (the tab bar is hidden)

two swipe gesture recognizers (left and right)

an outlet for the constraint between the left edge of the left container view and the UIViewController

In the UIViewController:

@IBOutlet weak var leftCon: NSLayoutConstraint! @IBOutlet weak var leftContainer: UIView! override func viewDidLoad() {    // Add notification for handle the menu selection    NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("updareConst:"), name: "updateConstraints", object: nil) } override func viewDidAppear(animated: Bool) {    // present the first view controller full screen    leftCon.constant = -leftContainer.frame.size.width } // Add actions for swipe gesture recognizers @IBAction func closeMenu(sender: UISwipeGestureRecognizer) {    leftCon.constant = -leftContainer.frame.size.width-16    UIView.animateWithDuration(0.3){        self.view.layoutIfNeeded()    } } @IBAction func openMenu(sender: UISwipeGestureRecognizer) {    leftCon.constant = 0    UIView.animateWithDuration(0.3) {        self.view.layoutIfNeeded()    } } func updareConst(notification: NSNotification){    leftCon.constant = -leftContainer.frame.size.width - 16    UIView.animateWithDuration(0.3) {        self.view.layoutIfNeeded()    } }

In the UITableViewController:

// Select the first tab var tbc: UITabBarController! override func viewDidAppear(animated: Bool) {    tbc = self.parentViewController!.childViewControllers[1] as! UITabBarController } // Handle row selection override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {    tbc.selectedIndex = indexPath.row    NSNotificationCenter.defaultCenter().postNotificationName("updateConstraints", object: nil) }

First selected View Controller:

// Hide tab bar override func viewDidLoad() {    self.tabBarController?.tabBar.hidden = true }

You can find more on this topic here: http://stackoverflow.com/questions/29425646/swift-slide-out-menu-without-sliding-the-navigationbar-programatically

[iosnippets-blog]

Pull to Refresh

//Add the UIRefreshControl func viewDidLoad() {    refreshControl = UIRefreshControl()    refreshControl.backgroundColor =  UIColor(netHex:0x4AABF7)    refreshControl.tintColor = UIColor.whiteColor()    self.refreshControl.addTarget(self, action: "refresh:", forControlEvents:    UIControlEvents.ValueChanged)    tableView.addSubview(refreshControl) } func refresh(sender:AnyObject) {    //Insert code to get the new data    self.refreshControl.endRefreshing()   //hide the control    self.tableView.reloadData() }

[iosnippets-blog]

TouchID check

To use this feature TouchID or Passcode should be used to unlock the phone. If TouchID is disabled this code would throw an error. Add the LocalAuthentication framework to the project and import it to your source file.

func touchIDLogin() {   let authenticationContext = LAContext()    var error:NSError?    // Check if the device has a fingerprint sensor and it's enabled    guard authenticationContext.canEvaluatePolicy(.DeviceOwnerAuthenticationWithBiometrics, error: &error) else {        // TODO: Show error        return    }    // Check the fingerprint    authenticationContext.evaluatePolicy(.DeviceOwnerAuthenticationWithBiometrics, localizedReason: "App message to user", reply: { (success, error) -> Void in        if success {            // TODO: Fingerprint recognised        } else {            // Check if there is an error            if let error = error {                // TODO: show error message for error.code: https://developer.apple.com/library/ios/documentation/LocalAuthentication/Reference/LAContext_Class/#//apple_ref/c/tdef/LAError            }        }    }) }

[iosnippets-blog]

Tuples!

Generic tupple declaration and usage in less than 10 lines

typealias CardIDNameImage = [String: (name: String, imageData: NSData)] typealias OneCardIDNameImage = (String, (name: String, imageData: NSData))

// code goes here

var currentCards = CardIDNameImage() var selectedCard = OneCardIDNameImage!() // filling the dictionary currentCards[ID] = (cardData.name, cardData.imageData) selectedCard = currentCards[index]

[iosnippets-blog]

AppStore like UITableView header

In Inteface Builder do: drag an UIView into the table. In UITableViewController do:

var headerView: UIView! override func viewDidLoad() {    super.viewDidLoad()    headerView = tableView.tableHeaderView    tableView.tableHeaderView = nil    tableView.addSubview(headerView)    tableView.contentInset = UIEdgeInsets(top: headerView.frame.size.height, left: 0, bottom: 0, right: 0)    tableView.contentOffset = CGPoint(x: 0, y: -headerView.frame.size.height) } override func scrollViewDidScroll(scrollView: UIScrollView) {    if scrollView.contentOffset.y <= -headerView.frame.size.height {        var headerRect = headerView!.frame        headerRect.origin.y = scrollView.contentOffset.y        headerView!.frame = headerRect    } }

[iosnippets-blog]

Get current location name (fast!)

There's a few lines of code that can get you the current location based on GPS data. It's just a few lines of code.

import CoreLocation class locationHandler: CLLocationManagerDelegate {    private let locationManager = CLLocationManager()    func requestLocation() {        locationManager.delegate = self        locationManager.requestWhenInUseAuthorization()        locationManager.requestLocation()    }    func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {        let locValue:CLLocationCoordinate2D = manager.location!.coordinate        let geocoder = CLGeocoder()        geocoder.reverseGeocodeLocation(manager.location!) { placeMarks, error in            if placeMarks!.count > 0 {                let mark = placeMarks![0]                print(mark.locality!) // TODO: use location name            }        }        location.getLocationForCoords(locValue.latitude, longitude: locValue.longitude, completion: gotCityName)    }    func locationManager(manager: CLLocationManager, didFailWithError error: NSError) {        print(error)    } }