Articles
In-depth articles about iOS programming, techniques, language features, architectual patterns, and beyond.
Understanding Date and DateComponents
Date and time might be among your list of the hardest things in programming (It is for me). Today, I'm going to talk about a basic concept of a Date and its companion DateComponents.
What is @escaping in Swift closures
Learn the meaning of @escaping, so you know what to do when you see it or when you need to write one.
Better print debugging with Xcode breakpoints
Print debugging is the simplest form of debugging technique, but it possesses some drawbacks. Let's see how we can make it better by using Xcode breakpoints.
Reduce boilerplate code with an automatic synthesis of Equatable and Hashable conformance
Equatable and Hashable are two essential protocols in the Swift world. Let's learn an old Swift feature that you might forget.
Setting default values for NSUserDefaults
NSUserDefaults is a go-to database for saving users' preferences. Learn how to populate it with your default values.
How to save/export an image in Mac Catalyst
Learn how to lets users save an image outside of your app’s sandbox.
3 lesser-known ways of using Swift enums
Three language features around Swift enumeration that you might not aware of.
Testing delegates and protocols in XCTest
Learn how to write unit tests for delegate/protocol methods.
Make a placeholder view in SwiftUI with redacted()
SwiftUI provides an easy way to convert to render any view into a placeholder style by redacting its content.
Quick way to open a Custom URL Scheme in iOS Simulator
In the past, the way I test a custom URL scheme is to go to Safari and open up any of my custom URLs. If you are still doing that, there is a better alternative.
How to renew an expired certificate with Fastlane Match
Fastlane Match saves us a lot of time managing certificates and provisioning profiles, but there is one thing that we have to do it manually. That is a renewal expired certificate. Luckily, we have to do it once a year. Let's learn how to do it.
How to Add inline images with text in SwiftUI
In iOS 14, we have a new way to put images along with texts.
How to declare Swift protocol for a specific class
Learn how to create protocols that constrain their conforming types to a given class.
A new way to manage the back button title in iOS 14 with backButtonDisplayMode
Apple adds a new way to control where the back button will pick up its title. Let's see how this make thing a lot easier going forward.
SVG image assets supported in Xcode 12
We finally get SVG supported and the best thing is it is backward compatible with some limitations.
What should you know about a navigation history stack in iOS 14
In iOS 14, long-press on the back button will bring up a history stack. Learn what you should consider with this new behavior.
Cross-promote apps with SKOverlay
SKOverlay is a new tool from Apple for doing apps cross-promotion.
UIToolbar in SwiftUI
In iOS 14, we finally have a way to set a toolbar for a view in a navigation view.
Custom navigation bar title view in SwiftUI
Learn how to set a navigation bar title view in SwiftUI.
A first look at matchedGeometryEffect
This modifier can interpolate position and size between two views. This is one of the most exciting features for me. Let's see what is capable of in this beta.
Should I learn UIKit or SwiftUI
The most popular question since the introduction of SwiftUI. Here is my thought after WWDC20.
Add custom SwiftUI view to View Library with LibraryContentProvider
A new way to create a reusable view.
Sleep sort: A sorting algorithm without compare
I can't tell it is a stupid or genius algorithm, but it sure got a beauty in it.
Animation delay and repeatForever in SwiftUI
Explore how delay and repeatForever affect an animation.
What is backIndicatorTransitionMaskImage
To set a custom image for the back button, we need to set an image to both backIndicatorImage and backIndicatorTransitionMaskImage, but what does backIndicatorTransitionMaskImage really mean?
Responsive design with UIStackView
Learn how UIStackView can help to make your UI adapt to size change.
Decode an array with a corrupted element
When working with an unstable, legacy, or third party API, you might get a malformed object in an array. Learn how to decode a JSON array with corrupted data in Codable safely.
How to set cornerRadius for only some corners
Learn to round specific corners, e.g., top-left and top-right.
History of Auto Layout constraints
Learn different ways to define Auto Layout constraints programmatically.
tintColor
Introduce you to one of an essential part of iOS theming. What is tintColor and its benefit.
SF Symbols: What is it, and how to use?
Introduction of SF Symbols, learn the basics, and how to use them.
How to create code snippets in Xcode
Create a reusable boilerplate snippet that you can use in the project.
How to create Neumorphic design in SwiftUI
Neumorphism or Neomorphism is a new design trend of UI recently. We are going to see how to implement this in SwiftUI.
How to create Activity Ring in SwiftUI
A guide to creating an activity-ring-like circular progress bar in SwiftUI. An in-depth tutorial of what I think when making a custom view. At the end of this article, you will be able to create the Activity ring used in the Activity app on Apple Watch.
Gradient in SwiftUI
SwiftUI has built-in ways to apply gradient color to its view. We are going to explore all three types of gradients provided, LinearGradient, RadialGradient, and AngularGradient.
SwiftUI basic Shape operations
Most complex custom views can be made by composing many basic shapes together. Today we will learn basic operations that we can do with them. It may seem trivial, but knowing these basics will benefit you in the future.
Sign in with Apple Tutorial, Part 4: Web and Other Platforms
Part forth in a series Sign in with Apple. Use Sign in with Apple JS to let users set up accounts and sign in to your website and apps on other platforms.
Sign in with Apple Tutorial, Part 3: Backend – Token verification
Part 3 in a series Sign in with Apple. In this part, we will see how backend can use the token to sign up/sign in users.
Sign in with Apple Tutorial, Part 2: Private Email Relay Service
Part 2 in a series Sign in with Apple. In this part, we will talk about the anonymous email address. How to make it work and its limitation.
Sign in with Apple Tutorial, Part 1: Apps
Part 1 in a series Sign in with Apple. In the first part, we will focus on the app part. What we need to do to add Sign in with Apple option in our app.
Dark color cheat sheet
A cheat sheet that tells you what colors to use to support dark mode. This is a guide for those who want to adopt dark mode, but too lazy to figure out which color to use.
UINavigationBar changes in iOS13, Part2: UISearchController
Revisit of navigation bar appearance — this time with a UISearchController. If you have a search bar in your navigation bar, you might need to recheck when you build your app against iOS13.
Data in SwiftUI, Part 3: Tools
The last part in a series on understanding data in SwiftUI. See all tools SwiftUI provided to declare different types of data and dependency. Learn when and how to use @State, @Binding, ObservableObject, @ObservedObject, @EnvironmentObject, and @Environment.
Data in SwiftUI, Part 2: Views as a function of data
Part 2 in a series on understanding data in SwiftUI. We will talk about the key that makes principles in part 1 possible in SwiftUI. And how this resulting in a reduction of the complexity of UI development.
Data in SwiftUI, Part 1: Data
Part 1 in a series on understanding data in SwiftUI. In the first part, we will try to understand the importance of data and how they play an essential role in SwiftUI.
UINavigationBar changes in iOS13
Apple brings a lot of appearance changes in iOS13, and the navigation bar is one of them. Cover everything you should know once you build your app against iOS13 (Xcode11).
Adopting iOS Dark Mode
A long-awaited feature has finally come to iOS. Join it or not is your choice to make. This article will guide you through it.
Modality changes in iOS13
In iOS13, the modal presentation gets a new look and dismissal gesture. This article will talk about what you can do with these new welcoming changes.
Custom UIHostingController
Learn how to create a custom subclass of UIHostingController and its benefit.
SwiftUI's ViewModifier
Learn a crucial concept in SwiftUI, view modifier, and a guide of how to create your custom modifier.
Better dependency injection for Storyboards in iOS13
Say goodbye to optional properties in your view controllers. In iOS13, you can inject those properties at a time of view controller creation.
UISplitViewController in SwiftUI
WWDC session shows us a way to create UISplitViewController with NavigationView in SwiftUI. It finally works in Xcode 11 Beta 3.
Browse SF Symbols on Mac
SF Symbols contain over 1,500 icons. It would be hard if you don't know the existence of SF Symbols App.