TimelineView is a SwiftUI view type that updates its body according to a provided schedule. We used to see SwiftUI views updating its body whenever the data it presents changes. TimelineView doesn’t follow this rule and allows us to build a super-custom schedule to update its content in a precise way. We will learn how to use TimelineView to create time-based views this week.
The new Swift Concurrency feature doesn’t only bring new opportunities for writing safer and more maintainable async code but also changes the way we handle errors. I didn’t use throw-catch keywords too much in my legacy code because usually, I had a completion callback with the Result type handled by the switch operator. This week we will talk about modeling error types and how we will address them in Swift with throw-catch keywords.
The Unified Logging System is a great way to build a proper logging system allowing you to understand different exceptional cases happening in your app. But it is not limited only to logging. It also provides a way to measure various events in your app. This week, we will learn how to use the Unified Logging System to measure app performance.
We discussed building a proper logging system instead of using the print function in the previous post. Apple provides us a framework to utilize its logging system backed by on-disk persistence. This week we will talk about exporting logs from the user devices by leveraging the power of the Unified Logging System.
We encounter bugs that are very hard to catch in the debugger from time to time. For example, it might occur only after a few days of app usage. In this case, running an app in a simulator and testing a feature doesn’t make sense. We need to understand what the user has done in the application and how it responds to user actions in this situation. Logging is an excellent technique to track and understand user actions through the app. This week we will learn how to implement proper logging functionality in our apps.
Last week we talked about the basics of CloudKit. We learned how to save and fetch data from the storage in the cloud and how to sync the data between devices. This week I want to cover the only reason why I have chosen CloudKit instead of Firebase, and it is data sharing between users.
CloudKit is an easy way to store data in the cloud, sync between multiple devices, and share it between the app’s users. This week we will learn how to start using CloudKit in the app to save and fetch data from the cloud and sync between multiple user devices.
A few weeks ago, we talked about the idea of Functional core and Imperative shell in Swift. The goal is to extract the pure logic using value types and keep side effects in the thin object layer. This week, we will look at how we can apply this approach in an opinionated way by using unidirectional flow.
We always want to provide a great user experience in our apps. The system can shut down your app when the user leaves it and when the user relaunches your app, the system creates it from scratch, and the current state of your app is lost. This is a bad user experience. To avoid this kind of situation, we should provide a state restoration mechanism. This week we will learn how to implement state restoration in SwiftUI.
We love value types because they provide us with safety and predictability, allowing us to reason about the code we write. But we still need objects to hold and mutate our app’s shared state. This week, we will discuss modeling our app’s logic by leveraging the value and reference semantics.