In the previous post, Advanced iOS Concurrency: Operations, we walked through the Operation concepts on iOS and made a demo application that fetches some posts of mine. After downloading the cover images, they will be applied to a simple filter, then be displayed in a table view. The application, however, has not been completed yet. There’s something that went wrong with our app making the app did not show downloaded images properly. In this tutorial, we will continue where we left off.
Get ready!

There are two techniques to deal with Concurrency in iOS: GCD - Grand Central Dispatch and Operations. Most of the time, GCD provides most of the concurrency capabilities you need. Yet, sometimes you’ll want some extra advanced customizations. It’s time to use Operations. This tutorial will introduce Operations in Swift, also explain when and why we use Operation instead of GCD.
Let’s switch the gears!

There is a big gap between knowing the path and walking through the path.

As I build this personal site, my first aim is to enjoy my hobby of writing. I write whatever I learn on along with my daily working, and share it. I hope my share will help someone when they need it. In return, I will have a deep of understanding what I write, and sometimes, receive “a cup of coffee” (Buy me Coffee) from a friend I’ve never met. ☺️

Power is gained by sharing knowledge, not hoarding it

Some friends come to me asking how to build a page like mine. I’m happy to share with you how I build it.
After this tutorial, you can build your own site within 5 minutes.
I hope to see your page launching soon!

As an iOS developer, you might have heard about TestFlight - a product of Apple that allows you to distribute your apps to beta users. So what can we do with it? Is it useful?
In this tutorial, we will walk through steps uploading a build to TestFlight, and invite users to test your app.
You also need to refer the previous post Shipping your app to Store to complete this tutorial.
Let’s have fun!

While I was searching for a book to boost my iOS development skill, I found this Swift Apprentice book on Raywenderlich’s book store. Take a quick look at the content of the book, I decided to add the book to my library.
Generally, If your iOS skill is mid-level or senior, you’re so confident with your master programming skill, this book is not for you. But if you’re looking for a book to strengthen your knowledge, or you just want to make sure everything you understand about Swift language is right - as my purpose, then take this book with you.
You’ll learn about very basic things like function, method, constants, control statement, etc. You’ll also have a chance to get in-depth knowledge about Stack/Heap allocation, protocol-oriented programming, and generic programming, which make your daily job more convenient, and you will find yourself like a master in Swift language.
Let’s drive-in!

As Swift has been becoming a flagship language for iOS development, most of the new iOS projects nowadays are built in Swift. However, there are many useful libraries are developed in other low-level programming languages such as Objective-C and / or C++ to boost performance. On the other hand, not all engineering positions are open to new projects, most of them are hired to maintain and develop new features based on the current code base that are built-in Objective-C.
Having the knowledge to mix the two languages within a single project is good for your iOS development skills as you will face it someday in your career path. In this post, I’m going to show you not only how to use Objective-C and Swift in one single project but also how to use a set of programming languages in a single one, including C++/ Objective-C/ Swift and React Native. Hope you will find this post interesting.
Let’s drive-in.

As an iOS developer, you might have chances to write applications on Mac os. And sometimes, your applications require users to authenticate before they can use your app. Enabling Google Sign in helps you save a lot of time to implement authentication flow. Unfortunately, it is a lack of documentation on how to integrate Google Sign in on Macos app, particularly in Swift. I once had a chance to implement this feature to my app. Now I want to share with you how we can do it. Let’s get started.

Some applications can survive without any data storage. Most other useful applications, however, save some state such as user configurations, user profile, goals, etc. on iOS, Apple provides Core Data as a framework to persist your valuable data. One thing to keep in mind that although CoreData can store data in a relational database it’s actually not a database engine.
In this tutorial, I will share with you a bad experience I faced when I work with Core Data. Hopefully, after reading my sharing, you will avoid facing the same problem in your projects.
Let’s get started.