I have ViewModel with ObservedObject conformance. One @Published variable is not used in view. Will its change cause view render?
Asked on 09/03/2024
1 search
In SwiftUI, a view's body is only re-evaluated when a property that it depends on changes. If you have a @Published variable in your ViewModel that is not used in the view's body, changes to that variable will not cause the view to re-render. SwiftUI creates dependencies only on the specific properties that are used within the view's body. This means that if a property is not read or used in the view, it does not establish a dependency, and changes to it will not trigger a re-render of the view.
This behavior is part of SwiftUI's efficient state management system, which ensures that views are only updated when necessary, based on the data they actually depend on. For more details, you can refer to the SwiftUI essentials session.
What’s new in SwiftUI
Learn how you can use SwiftUI to build great apps for any Apple platform. Explore a fresh new look and feel for tabs and documents on iPadOS. Improve your window management with new windowing APIs, and gain more control over immersive spaces and volumes in your visionOS apps. We’ll also take you through other exciting refinements that help you make expressive charts, customize and layout text, and so much more.
Enhance your UI animations and transitions
Explore how to adopt the zoom transition in navigation and presentations to increase the sense of continuity in your app, and learn how to animate UIKit views with SwiftUI animations to make it easier to build animations that feel continuous.
Run, Break, Inspect: Explore effective debugging in LLDB
Learn how to use LLDB to explore and debug codebases. We’ll show you how to make the most of crashlogs and backtraces, and how to supercharge breakpoints with actions and complex stop conditions. We’ll also explore how the “p” command and the latest features in Swift 6 can enhance your debugging experience.