OrchardNest

In my previous article, you have learned that actors can help us in preventing data races by ensuring mutual exclusion to its mutable states. This statement is true as long as we are accessing the mutable states within the actors. If the...

When the first time I saw the WWDC presentation about actors, I was thrilled with what it is capable of and how it will change the way we write asynchronous code in the near future. By using actors, writing asynchronous code that is free...

Data races — the worst nightmare of all developers! They are hard to detect, very unpredictable, and extremely difficult to fix. Apple has given developers various toolsets such as NSLock and serial queues to prevent data races from...

Traditionally, when we want to make a network request, we must use the closure-based URLSession APIs to perform the request asynchronously so that our apps can be responsive while waiting for it to complete. With the release of Swift 5.5,...

Writing asynchronous code has always been a challenging task for developers. Throughout the years, Apple has provided various tools such as grand central dispatch (GCD), Operations, and dispatch queue that help developers in writing...

When developing an iOS app, oftentimes we need to store sensitive data (password, access token, secret key, etc) locally. For junior developers, the first thing that comes to mind will be storing it using UserDefaults. However, as we all...

As a developer, very often we need to deal with complex algorithms that take hours or even days to develop. Thanks to Swift’s higher-order functions such as map, reduce, filter, etc, some of those complex algorithms can now be easily...

In October 2020, I published an article that discusses how to reload a table and collection view cell when using diffable data source. The article shows you how to use 2 totally different approaches when reloading cells with reference and...

If I ask which LLDB command you used the most? I am sure most iOS developers will answer po. But did you know that you can actually define your own custom LLDB command using purely Swift code? In this article, I would like to show you what...

In iOS 14, Apple shows their love to SwiftUI by giving it automatic keyboard avoidance, it is turned on by default, meaning all your SwiftUI views can get this awesome feature automatically once you build your apps for iOS 14....

This is a story about me spending 1 hour just to remove an UIImageView rounded corners. I am sure most fellow developers out there will have a similar experience where you have to spend an unreasonable amount of time just to complete a...

Back in June 2020, during WWDC20, Apple announced that starting from iOS 14, developers will have to get permission from users before tracking them. In other words, apps won’t be able to access the device’s IDFA (Identifier for...

When Apple introduced limited photo access in iOS 14, some iOS developers were not so happy about it, it seems like Apple was trying to make developers’ life harder. Any apps (old or new) that want to support iOS 14 or higher will...

If you are like me, have been using a diffable data source section snapshot for quite some time, I am sure you will notice that the code to construct a section snapshot is actually quite difficult to reason about. The append(_:) and...

Result builders (formerly known as function builders) is a new feature introduced in Swift 5.4, it is the technology that empowers ViewBuilder in SwiftUI. With the release of Xcode 12.5 (currently in beta stage), Apple has made it...

A couple of months ago, I have wrote an article about “The Modern Ways to Reload Your Table and Collection View Cells“. The concept is simple, we first identify the desired data source snapshot item, update it, and then apply...

As iOS developers, we always tend to use an actual device for testing during app development. A real device can provide an actual hardware environment similar to the production release, it also gives us a better idea about the UI / UX of...

The diffable data source section snapshot is an UIKit component introduced in iOS 14. It opens up new possibilities for developers to build various types of hierarchical lists using collection view declaratively. Even though it is such a...

The expandable date picker is a very common UI component in the Apple design system. You can find it in the iOS Reminder and Calendar App. Even though it does not come out of the box with UIKit, we can easily create one using a custom cell...

Recently I have been requested by my client to add a large title navigation bar into their app’s main screen, on top of that the large title should automatically collapse when users start scrolling. I think to myself: how hard could...

Recently my team and I are working on an image processing app for a client. The app works pretty well on most of the aspects. Unfortunately, when we start loading HD images on screen, the app will crash occasionally due to “out of...

It’s been a while since I covered topics related to Lottie animation. In my previous article, “Modifying Lottie Animation with Value Providers“, I have discussed how developers can leverage different kinds of value...

In my previous article, we had discussed how to add a declarative header and footer to the UICollectionView List. This week, let’s take one step further and talk about how you can add a custom header to your collection view...

If you have been following my work for the past couple of months, you have probably read my articles about constructing a basic and expandable list declaratively using cell registration, content configuration, and data source snapshot. In...

In iOS 13, Apple introduced diffable data source and snapshot, defining the modern era of table view and collection view. Prior to this, reloading a table or collection view cell can be easily done by calling one of the following...

In last week’s article, we learned how to leverage the NSDiffableDataSourceSectionSnapshot to create an expandable list in a single-section collection view. In this article, we will pick up where we left off by modifying last...

Expandable list or some might call it expandable table view, is a very common UI design that is used in a large variety of apps. Despite the fact that it is so popular, UIKit does not have any native APIs that support this kind of layout....

Since the publishing of my article “UICollectionView List with Custom Cell and Custom Configuration“, a lot of my readers have been asking me whether it is possible to design the custom UICollectionViewListCell in the interface...

In iOS14, Apple introduced the list layout in UICollectionView, allowing developers to easily create a list using UICollectionViewListCell — A collection view cell that comes along with iOS14 which provides list features and default...

Since the introduction of UICollectionView in iOS6, UICollectionView has been the default component to go to when it comes to building a grid layout. In WWDC 2020, Apple pushes the usability of UICollectionView to the next level by...

Imagine you have an array of Device objects and you want to group them by category as shown in the image below: How should you go about in solving this problem? Before Swift 5, the most straightforward way is to loop through each device in...

When it comes to third party backend authentication services for iOS apps, the first that comes to mind for sure is Firebase Authentication. By using Firebase Authentication, iOS developers can skip the hassle of setting up a secure...