Hi, I’m Ole. I’m a developer from Berlin and co-author of Advanced Swift. Here, I mainly write about Swift and app development on Apple platforms. More about me.

1. An iOS alert view with a text field and a “smart” OK button

   I wrote a UIAlertController extension that allows you to perform validation of the text the user has entered while the alert is on screen. It’s nothing earth-shattering, but what I like about it is that the behavior is entirely encapsulated in the initializer. Clients only deal with the same UIAlertController object they’re used to. More >

   August 13, 2018

2. Migrating an Objective-C class to Swift using subclassing

   Following up on last week’s article on migrating an Objective-C class to Swift using extensions, I discuss an alternative approach: adding a Swift subclass to the Objective-C class you want to convert. More >

   August 9, 2018

3. Migrating an Objective-C class to Swift: a piecemeal approach

   A piecemeal migration of an existing Objective-C class to Swift often means adding a Swift extension to the class. I describe a technique how you can provide stored properties to the the Swift extension, even if those properties aren’t compatible with Objective-C. More >

   July 31, 2018

4. Nullability warnings with libextobjc’s @keypath macro

   Xcode 10 started emitting strange nullability violation warnings for the popular @keypath macro in Objective-C. An explanation where the warnings come from and of the fix I found. More >

   July 27, 2018

5. Thoughts on @dynamicMemberLookup

   Dynamic member lookup is possibly the most controversial new feature in Swift 4.2. If misused, it has the potential to fundamentally change what constitutes Swift code. It also has the potential to open Swift up to other communities and allow it to grow into new fields. More >

   June 22, 2018