Скачать или смотреть Resolve SwiftUI Alert Display Issues on API Failure

Learn how to ensure your `SwiftUI Alert` appears every time an API call fails by properly managing the error state in your app.
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This video is based on the question https://stackoverflow.com/q/69394812/ asked by the user 'Valerio' ( https://stackoverflow.com/u/813728/ ) and on the answer https://stackoverflow.com/a/69402636/ provided by the user 'Asperi' ( https://stackoverflow.com/u/12299030/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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How to Ensure Your SwiftUI Alert Appears on API Failure Every Time

In the world of iOS development, managing user feedback effectively is crucial, especially when dealing with asynchronous tasks like API calls. One common problem developers face is ensuring that alerts are displayed consistently when an error occurs. In this guide, we will explore a specific issue encountered in a SwiftUI app where an alert is only shown the first time an API call fails, and then fails to show in subsequent attempts. We will provide a clear, step-by-step solution to solve this issue.

The Problem Statement

Imagine you have a SwiftUI application that fetches data from a few API endpoints, managed by respective ViewModels. Your primary concern is to inform users when an API call fails. However, users experience the following issue:

When the button to fetch the data is pressed and the API fails, an alert appears informing them of the error.

Upon subsequent attempts to fetch data (even after an error has occurred), the alert fails to appear again, even though the error state is correctly being set.

This issue can be confusing for your users and can significantly impact the usability of your app. Fortunately, there is a straightforward solution to ensure the alert appears whenever an error arises.

Understanding the Code Structure

Let's break down the relevant parts of the code that handle API communication and alert presentation.

ViewModel Code

The LanguageViewModel class handles API fetching and error management:

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

ContentView Code

Here’s the part of your UI that presents the alert based on the error state:

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

Solution to the Problem

The solution to ensuring your alert reappears on subsequent errors is to reset the error state when the alert is dismissed. Here’s how to modify the alert presentation code:

Updated Alert Code

You need to adjust the .alert modifier as follows:

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

Key Changes Explained

Resetting the Error: The crucial part of this solution is resetting the error property to nil inside the dismiss button of the alert. This ensures that the condition for presenting the alert (self.languageViewModel.error != nil) can be satisfied again during the next API call if another error occurs.

Conclusion

Handling errors gracefully and providing users with clear feedback is essential for a good user experience in mobile applications. By updating your alert's dismiss action to reset the error state, your SwiftUI application will inform users of issues every single time an API call fails. This approach not only resolves the immediate problem but also strengthens your app's robustness in handling asynchronous operations.

If you've faced a similar issue could it have been resolved using the method described above? Feel free to share your thoughts and experiences in the comments below!