Recent articles

This post was originally published in 2021 and has been touched up for 2024 WWDC is always an exciting time for iOS engineers. It’s the one week a year where we’re all newcomers to a whole range of features and APIs that Apple has just unleashed upon the world through their latest Xcode, macOS, iOS, […]

A common pattern on iOS, and in Swift, is to define an instance of an object that you can access from any place in your app. Common examples are URLSession.shared, FileManager.default, and UserDefaults.standard. These objects can all be considered shared instances, or globally available instances. Defining a shared instance is commonly done as follows: struct […]

When you’re working with Arrays in Swift, it’s likely that you’ll want to sort them at some point. In Swift, there are two ways to sort an Array: Through the Comparable implementation for each element in your array By providing a closure to perform a manual/specialized comparison between elements If you have a homogenous array […]

Decoding data, like JSON, is often relatively straightforward. For a lot of use cases, you won’t need to know or understand a lot more than what I explain in this post. However, sometimes you need to dive deeper into Codable, and you end up writing custom encoding or decoding logic like I explain in this […]

The default behavior for Codable is often good enough, especially when you combine this with custom CodingKeys, it’s possible to encode and decode a wide variety of JSON data without any extra work. Unfortunately, there are a lot of situations where you’ll need to have even more control. The reasons for needing this control are […]

In the introductory post for this series you learned the basics of decoding and encoding JSON to and from your Swift structs. In that post, you learned that your JSON object is essentially a dictionary, and that the JSON’s dictionary key’s are mapped to your Swift object’s properties. When encoding, your Swift properties are used […]

Virtually every modern application needs some way to retrieve, and use, data from a remote source. This data is commonly fetched by making a network request to a webserver that returns data in a JSON format. When you’re working with Javascript, this JSON data can be easily decoded into a Javascript object. Javascript doesn’t have […]

Often, you’ll want you Swift models to resemble JSON that’s produced by an external source, like a server, as closely as possible. However, there are times when the JSON you receive is nested several levels deep and you might not consider this appropriate or needed for your application. Or maybe you’re only interested in a […]

This article covers a topic that is extensively covered in my Practical Core Data book. This book is intended to help you learn Core Data from scratch using modern techniques and every chapter features sample apps in SwiftUI as well as UIKit whenever this is relevant. When you use Core Data in a UIKit or […]

When you’re learning about databases or multithreaded programming, it’s likely that you’ll come across the term "atomic" at some point. Usually you’ll hear the term in the context of an operation. For example, an atomic read / write operation. Or atomic access to a property. But what does this mean? Generally, you can summarize atomic […]