Swift by Sundell - Swift by Sundell Newsletter #27

👋 Hi everyone

Swift by Sundell now includes over 400 freely available articles (not counting any podcast episodes or videos), which I’m incredibly proud of, but it has also resulted in a quite significant (although completely self-created) problem — it’s become increasingly difficult to get a good overview of everything that the site has to offer on a given topic.

Sure, there are category pages, a search feature, tags, and so on, but those all still require each user to actively search, browse and discover each topic on their own. So, over the past few months, I’ve been experimenting with various ways to make that process easier, and I eventually realized that the keyword that I was looking for was right there in the previous sentence — discover.

The result of all of those experiments is Swift by Sundell Discover, a brand new feature that lets you easily explore all of the articles, tips, podcast episodes and videos that I’ve published on a given topic. I picked SwiftUI as the first topic, and I’m aiming to publish another set of topics over the next few weeks.

I hope you’ll find this new feature useful, and that you’ll enjoy the rest of this month’s content, which includes 8 new articles and 2 new podcast episodes. Let’s dive in!

📖 Weekly articles

For 194 weeks, I’ve been publishing a new article about Swift every Sunday. These articles were added during the past month:

Testing networking logic in Swift

How networking code can be tested without needing to introduce complex abstractions within our production code, by using system-provided APIs for overriding and mocking various kinds of requests.

Handling loading states within SwiftUI views

A few different patterns and approaches that can be used to handle and render asynchronous loading states within SwiftUI-based views.

The power of extensions in Swift

An overview of the sort of patterns and techniques that Swift’s extensions enable us to adopt, and how extensions can turn out to be one of the most powerful features that the language has to offer.

Connecting and merging Combine publishers in Swift

How Combine’s operators for connecting and merging publishers can be used to solve real-world problems, such as nested network calls, handling multiple input sources, and more.

🎧 Podcast episodes

The Swift by Sundell podcast is a bi-weekly show featuring special guests from all around the Swift community. You can find it in your podcast player of choice, for example Apple Podcasts or Overcast. These episodes were published during the past month:

83: “Adventure into widgets”, with Simon Støvring

Simon Støvring, the developer behind several powerful iOS productivity apps, including Scriptable, joined me on this episode that’s all about the new home screen widgets introduced in iOS 14. Topics include how to create and update dynamic widgets, managing and sharing data between an app and its widgets, and much more.

84: “Key paths, functions and closures”, with Vincent Pradeilles

Vincent Pradeilles joined me to discuss various ways to use Swift language features like key paths and closures, how they relate to patterns typically used within functional programming, and when and how to adopt such patterns.

⭐️ Swift tips

I love to share shorter tips, tricks and techniques with the community. You can also find all of the tips that I’ve ever posted as mini-articles right here. These are the tips I shared during the past month:

Importing interactive UIKit views into SwiftUI

Importing static UIKit views into SwiftUI is often quite straightforward, but it can be somewhat trickier to bridge patterns like delegation and target/action with the declarative world of SwiftUI. So let’s take a look at how to do just that.

Lazy property observers

Property observers can now be attached to lazy properties, which makes it possible for us to automatically observe when a new value was assigned to a given property, even if its value is lazily loaded when first accessed.

Publishing constant values using Combine

Although Combine is definitely the most useful when it comes to building highly dynamic data pipelines for publishing streams of values over time, sometimes we might also want to use it to emit constant values as well. That’s what this article is all about.

⁉️ Questions & Answers

Answers to common questions about Swift development, or about my work in general. I answered this question during the past month:

When does the order of SwiftUI modifiers matter, and why?

A look at what goes on under the hood when we apply a modifier to a SwiftUI view, and why the order of certain modifiers can have a quite substantial impact on the rendered result of a given view.

😊 Until next time

That’s it for this edition! I hope you enjoyed this newsletter. I always love to hear your feedback, so feel free to either reply to this email, or contact me on Twitter @johnsundell. I read every single piece of feedback that I get, and I try to reply to as many people as I possibly can.

Thanks for reading! 🚀

- John