Скачать или смотреть How to Avoid SwiftUI Timer Resets When Updating ObservedObjects

Learn how to keep your SwiftUI timer running without resetting it when `ObservedObjects` change. Follow this guide for a solution and improved UI experience.
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How to Avoid SwiftUI Timer Resets When Updating ObservedObjects

Managing state in an app can often lead to tricky situations, especially when you're working with SwiftUI's ObservedObject. One common issue that developers face is when a timer resets every time another ObservedObject in the View updates. In this guide, we will dive deep into how to solve this issue effectively, ensuring your timer continues to run smoothly regardless of other changing states.

The Problem: Timer Resetting in SwiftUI

Imagine you have built an iOS application using SwiftUI that includes:

A timer that needs to keep track of time.

Several ObservedObject instances that trigger state changes.

As you interact with the app, each change in the ObservedObject inadvertently causes the timer to reset – frustrating, isn’t it?

Here’s a simplified version of how the original code might look:

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Symptoms of the Problem

Timer resets every time you change an option in the picker.

On using onAppear, the timer does not start correctly after the UI changes.

So, how do we solve this?

The Solution: Utilizing StateObject

The solution to avoiding the timer reset lies in how we manage our ObservedObject. Instead of creating a new instance of the timer data every time the view appears, you can leverage -StateObject. This keeps your timer data intact across multiple view refreshes.

Step-by-Step Implementation

Declare Timer as StateObject
Instead of using -ObservedObject for your timer, use -StateObject which will ensure the instance maintains its state as views are updated.

Adjust Your View Structure
Here’s how you can modify your original ContentView:

[[See Video to Reveal this Text or Code Snippet]]

Updated Timer View

Make sure your CurrentDateView fetches the timerData correctly:

[[See Video to Reveal this Text or Code Snippet]]

Additional Considerations

To keep your views more reusable, consider passing parameters that are needed rather than state.

Be mindful of how often state changes occur. If your application allows rapid changes, the timer may still exhibit unexpected behavior.

Conclusion

Integrating -StateObject into your SwiftUI views is a powerful way to manage state effectively and avoid unwanted resets in your timers. This simple technique can save you from frustration and enhance the user experience in your application.

Now that you've learned how to manage your SwiftUI timers effectively, go ahead and implement it in your projects, ensuring they behave as expected without interruptions!

If you have further questions or run into issues, feel free to leave a comment or reach out for more help!