In my previous post about Combine, I introduced you to Functional Reactive Programming (FRP) and I’ve shown you can subscribe to Combine publishers using the sink(receiveCompletion:receiveValue:) method. I also showed you how you can transform the output of publishers using some of its built-in functions like map and collect. This Read more…
The Combine framework. Silently introduced, yet hugely important for iOS. It didn’t get any attention during the big Keynote at WWDC 2019, but as soon as folks were in the sessions they knew that Combine was going to be huge. It implements a Functional Reactive Programming (FRP) paradigm that’s similar Read more…
Recently I wanted to build a generic data source layer. This data source would be able to return pretty much anything from a local cache, or if the local cache doesn’t contain the requested object, it would fetch the object from a server and then cache the result locally before Read more…
Now that Apple has split iPadOS into a separate OS, and launched Catalyst to enable developers to compile their iPad apps for the Mac, there’s a whole new multi-window paradigm we must understand and cater for. Up until this year, we only had to worry about a single window for Read more…
When you create a new project in Xcode 11, you might notice something that you haven’t seen before. Instead of only creating an AppDelegate.swift file, a ViewController.swift, a storyboard and some other files, Xcode now creates a new file for you; the SceneDelegate.swift file. If you’ve never seen this file Read more…
The Swift team has recently released Swift 5.1. This version of the Swift language contains many cool features like Function Builders that are used for SwiftUI and Property Wrappers that can be used to add extra functionality to properties. This release also contains a feature called Module Stability. But what Read more…
In part 1 of this two-part blog post, you’ve learned how to write synchronous unit tests for a login view model. As a reminder, you saw how to implement tests for the following requirements: When both login fields are empty, pressing the login button should trigger an error that informs Read more…
If you’re into writing clean, testable and maintainable code you must have come across the term “Dependency Injection” at some point. If you’re not sure what dependency injection is, that’s okay. I will explain it briefly so we’re all on the same page before we get to the main point Read more…
It’s been almost two years since I blogged on this page. I know, two years is a long break for a person that claims to love “Writing about my everyday coding problems and solutions”. Well, there is a very valid reason for my absence because I have been working on Read more…
Every iOS developer I know dreams of writing code that’s DRY, modular, testable and reusable. While this is a great goal to strive for it’s often quite hard to write code that is completely modular. It just takes one oversight to blow most of the modularity you have achieved right Read more…