Imported and Exported UTIs

October 24th, 2018

Filed under: iOS Development, Mac Development, Xcode | Be the first to comment!

If you create a document-based app project in Xcode, select the app target in the project editor, and click the Info button, you will see sections for imported and exported UTIs. If you have any of the following questions: What is a UTI? When would I use an imported UTI? When would I use an […]


Working with File Wrappers in Swift

July 17th, 2018

Filed under: Cocoa, Mac Development | Be the first to comment!

Back in 2010 I wrote an article on working with file wrappers. Recently I needed to work with file wrappers, and I noticed the file wrapper code is much different in Swift so I figured working with file wrappers in Swift would be a good topic for an article. This article assumes you’re creating a […]


Xcode Turns on the App Sandbox for New Cocoa Projects

July 11th, 2018

Filed under: Cocoa, Mac Development, Xcode | Be the first to comment!

I ran into an issue with a new document-based Cocoa app throwing exceptions when I tried to save the document. It turns out the issue was the App Sandbox, which is turned on when you create a new Cocoa application project in Xcode. You can see the App Sandbox settings by selecting your project from […]


Getting Started with Unit Testing in Swift 4

June 13th, 2018

Filed under: Cocoa, iOS Development, Mac Development, Xcode | Be the first to comment!

One of the most read articles on this blog is An Introduction to Swift Unit Testing. The article is almost four years old and uses Swift 1. Because of that I have decided to build upon that article here, updating the code to Swift 4 and adding an example project to unit test. The Project […]


Checking Modifier Keys in Swift

January 22nd, 2018

Filed under: Cocoa, Mac Development | Be the first to comment!

Checking for modifier keys (Command, Control, Option, and Shift) when handling events is different in Objective-C and Swift. In Objective-C you perform a bitwise AND operation to check if modifier keys were held down. In Swift you check if the event’s modifier flags contains the specific modifier key. The following example demonstrates how to check […]