Category Archives: Patterns

Design Patterns in Swift: Observer

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Continuing on our journey with design patterns, this week we’ll visit the observer pattern. This is a really simple pattern to implement. We’ll quickly go through some theory and get down to business. Hopefully, by the end of the article, you’ll be using the pattern in your projects. The Observer… Read more »

Design Patterns in Swift: Abstract Factory

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Abstract factory is one of the creational design patterns. You probably encountered it in your development without realising. Here we’ll cover the swift version of the text-book version of the design pattern and say a few words about the dependency inversion principle. Abstract Factory We’re all taught to code to… Read more »

DispatchGroup vs. OperationQueue in Swift

You probably found yourself in a situation where you had to do a bunch of asynchronous tasks and you just wanted to get notified when all of them finish. There are two easy ways of doing this: DispatchGroup and OperationQueue. We’ll cover them both in this post. The Story We’ll… Read more »

Understanding Operation and OperationQueue in Swift

There are more ways than one to do concurrent operations on iOS. In this article, we’ll cover how to use Operations and OperationQueue to execute concurrent operations. There’s a lot to be said (and written) about concurrency on iOS and I don’t really want to bore you to death by… Read more »

Unit Tests with Dependency Injection

A few weeks back I wrote an article on dependency injection and how to use it. Here I’ll cover how to use dependency injection in your unit tests. Dependency Injection I won’t talk a lot about dependency injection in this article, there’s a whole article on the subject, and I… Read more »

Design Patterns in Swift: Singleton

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Everyone has heard of singletons. It’s probably the simplest design pattern there is, yet, there are a few catches when implementing it. In this post, I’ll go over the singleton design pattern and the little gotchas that might end up in a crash or an inconsistent state of the app. Singleton… Read more »

Using Dependency Injection

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In this post, we’ll cover one very useful technique called dependency injection and we’ll look at some examples on to use it in your iOS project. What is it? Dependency Injection is a technique where you would inject dependencies into an object. Let’s say you’re building an app that will display… Read more »