MissinKit

License

The code is released under the MIT License.

What's Inside?

iOS Native Pluralization

As Xamarin's current NSString.LocalizedFormat() method is useless, there's no way to use iOS native pluralization. To turn this very important feature on, there's the NSStringUtility.LocalizedFormat() method to replace Xamarin's counterpart:

NSStringUtility.LocalizedFormat(NSBundle.MainBundle.GetLocalizedString("%d file(s) remaining"), 2)

If key is found, it formats the string accordinig to the .stringsdict file. Otherwise, it falls back and prints "2 file(s) remaining".

WARNING! The NSStringUtility.LocalizedFormat() method does not work on 64-bit simulators.

Instead of using the NSStringUtility.LocalizedFormat() or NSBundle.GetLocalizedString() methods directly, use the convenient extension methods which are more than enough for the vast majority of cases:

// instead of
str = NSBundle.MainBundle.GetLocalizedString("key");
// use
str = "key".Localize();

// instead of
str = string.format(NSBundle.MainBundle.GetLocalizedString("key"), 2, "text");
// use
str = "key".Localize(2, "text");

// instead of
str = NSStringUtility.LocalizedFormat(NSBundle.MainBundle.GetLocalizedString("key"), 3);
// use
str = "key".Localize(3);

These methods work with both .strings and .stringsdict files.

Network Reachability

The Reachability class is a port of Apple's Reachability sample app to monitor the network state of an iOS device.

var r = new Reachability("apple.com");
r.ReachabilityChanged += (s, e) => Debug.WriteLine($"Network Status: {r.Status}");

Date Utilities

There are two extension methods providing a quick way to convert DateTime to NSDate and vice-versa.

NSDate nsdate = DateTime.Now.ToNSDate();
DateTime datetime = nsdate.ToDateTime();

Not a big deal, but convenient.

Changing Current Locale on the Fly

Since iOS doesn't provide an easy way to change NSLocale.CurrentLocale programmatically, there's a utility to help with that.

var date = new DateTime(2018, 1, 1).ToNSDate();
var formatter = new NSDateFormatter() { DateFormat = "EEEE" };

L10n.OverrideCurrentLocale("es_MX");

formatter.Locale = NSLocale.CurrentLocale;
Debug.WriteLine(formatter.StringFor(date)); // outputs 'lunes'

L10n.RestoreCurrentLocale();

formatter.Locale = NSLocale.CurrentLocale;
Debug.WriteLine(formatter.StringFor(date)); // outputs 'Monday'

Overriding or restoring the current locale triggers NSCurrentLocaleDidChangeNotification.

iOS 11 Fallback

Since iOS 11 introduced some breaking changes to UIView layout handling, there are a few fallback extension methods to reduce boilerplate code required to handle those changes.

The SafeAreaLayoutGuide() method returns the UIVIew.SafeAreaLayoutGuide for iOS 11 and later and falls back to a layout guide based on the frame rectangle of the current view for older systems.

var insets = view.SafeAreaLayoutGuide();

The SafeAreaLayoutGuide() method uses the frame layout guide as a fallback. The frame layout guide is a layout guide anchors of which simply return its owning view's anchors. The frame layout guide is created using the FrameLayoutGuide() extension method which is especially helpful for the scenarios like this:

var isIos11OrLater = UIDevice.CurrentDevice.CheckSystemVersion(11, 0);
var widthAnchor = isIos11OrLater ? view.SafeAreaLayoutGuide.WidthAnchor : view.WidthAnchor;
var heightAnchor = isIos11OrLater ? view.SafeAreaLayoutGuide.HeightAnchor : view.HeightAnchor;
// more checks here...

To avoid checking for all anchors of the view you need, simple use the frame layout guide:

var layoutGuide = isIos11OrLater ? view.SafeAreaLayoutGuide : view.FrameLayoutGuide();

This is exactly what the SafeAreaLayoutGuide() method does so you don't even need to check the system version. But you can use the FrameLayoutGuide() method as a fallback for other layout guides introduced in iOS 11 if needed.

The initial call of the FrameLayoutGuide() method adds the returned layout guide to the view's layout guides, so all subsequent calls return the already existing instance instead of creating a new one every time.

Note that the FrameLayoutGuide() method returns the FrameLayoutGuide property for UIScrollView.

The SafeAreaInsets() method returns the UIVIew.SafeAreaInsets for iOS 11 and later and falls back to UIEdgeInsets.Zero for older systems.

var insets = view.SafeAreaInsets();

The AdjustedContentInset() method returns the UIScrollView.AdjustedContentInset for iOS 11 and later and falls back to UIScrollView.ContentInset for older systems.

var insets = scrollView.AdjustedContentInset();

Update Watcher

This is a simple utility for a quick check for app updates in App Store.

var updateWatcher = new UpdateWatcher(3); // Checks every 3 days
var updateAvailable = await updateWatcher.CheckForUpdateAsync();

if (updateAvailable)
    // Notify user

Machine Epsilon

As on some ARM devices both float.Epsilon and double.Epsilon equate to zero, the constants MachineEpsilon.Single and MachineEpsilon.Double are recommended to be used instead.