Fixing the Issue of @Published Not Updating UI in SwiftUI

Learn how to solve the issue of SwiftUI views not refreshing when using @Published properties in your Combine framework implementations.
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Fixing the Issue of @Published Not Updating UI in SwiftUI

When working with SwiftUI and the Combine framework, developers may encounter an issue where the UI doesn't update as expected when using @Published properties. This problem can be particularly frustrating if you've set everything up correctly, only to find that interactions within your app seem to have no impact on the visible UI.

The Problem: Text Not Updating with @Published

In this guide, we’ll delve into a common scenario: updating the current day of the week based on user interactions, such as toggling arrows to move forward or backward in the week. The setup seems straightforward, but, unfortunately, the view remains unchanged even when the @Published property's value is indeed updated.

Understanding the Current Implementation

The initial implementation involves an ObservableObject GrabCurrentDate, with a @Published variable called currentWeekday. Here's a simplified summary of what we've set up:

Fetching Current Day: The current day of the week is fetched using the dayNumberOfWeek function.

Switch Statement: A switch statement translates a day index into a human-readable string format for display.

SwiftUI View: A simple SwiftUI view allows users to toggle the day by tapping on arrows.

However, despite these implementations, the UI fails to refresh. The underlying issue lies in how the @Published properties are being handled in the view lifecycle.

A Better Solution for UI Updates

To effectively address this issue, we can restructure our ObservableObject and its interaction with the SwiftUI view. Here’s a rundown of our improved implementation:

1. Define Your Enum for Days of the Week

By creating a structured enum for weekdays, we can utilize it in a cleaner and more type-safe manner:

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2. Create an ObservableObject

Now, let’s set up the CurrentDate observable. It will maintain the current day and provide methods to increment and decrement it:

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3. Update the Date Extension

To get the current day of the week, we use the following extension:

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4. Create the SwiftUI View to Reflect Changes

Finally, we’ll use SwiftUI to construct our view. This view utilizes @StateObject to monitor changes in the observable object:

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Conclusion

By restructuring your use of @Published, utilizing enums, and ensuring that change notifications properly connect to your SwiftUI views, you'll achieve the desired effect where the interface updates dynamically as user interactions occur.

This approach helps maintain both clean code and efficient UI performance while providing a clearer path for further enhancements or changes. If you find your UI still not updating as intended, double-check your ObservableObject and ensure that you're using @StateObject properly in SwiftUI.

Happy coding!