Скачать или смотреть How to Get String Resources in ViewModel

Learn how to properly access string resources in your Android ViewModel without running into common exceptions such as ResourceNotFound. Understand the correct approach using AndroidViewModel or Hilt dependency injection.
---
This video is based on the question https://stackoverflow.com/q/68723687/ asked by the user 'Sunbey13' ( https://stackoverflow.com/u/14729932/ ) and on the answer https://stackoverflow.com/a/68725244/ provided by the user 'Dương Minh' ( https://stackoverflow.com/u/15369207/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Get string resources in viewmodel

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
How to Get String Resources in ViewModel: A Comprehensive Guide

In the world of Android development, particularly when using Kotlin and RxJava, managing string resources efficiently in your ViewModel can be a challenge. Many developers encounter issues when attempting to display strings, including values formatted with percent signs, in their UI components like TextView. If you find yourself grappling with this problem, you're not alone. This guide will walk you through the steps to properly access string resources within your ViewModel, ensuring you display values correctly and avoid common pitfalls.

The Problem: A Common Exception

Let’s break down the specific problem many developers face when trying to show a percentage value, for example, "15 %," in a TextView from a ViewModel. Here’s a glimpse of the code that might lead you to confusion:

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

When executing the above, you might encounter an exception error such as:

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

This error suggests that the application cannot find the specified resource, which often stems from a misunderstanding of how to correctly access resources in ViewModels—particularly when dealing with context.

The Solution: Properly Accessing Resources

To resolve this issue, we need to ensure that we are using the correct context to access string resources. Here’s a breakdown of different approaches depending if you’re using a traditional ViewModel or leveraging Hilt for dependency injection.

1. Use AndroidViewModel Instead

If you’re not using Hilt, the best approach is to use AndroidViewModel instead of the standard ViewModel. AndroidViewModel allows you to pass the Application context into your ViewModel. Here’s how to implement it:

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

This change gives you access to the application's context, allowing you to retrieve string resources correctly.

2. Using Hilt for Dependency Injection

If you’re employing Hilt in your project, you can inject the Application context directly into your ViewModel. This method avoids subclassing AndroidViewModel, making your code cleaner. Here’s an example:

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

3. Accessing String Resources

Once you have either the Application context or the injected context, you can easily retrieve string resources as follows:

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

Now, if you need to concatenate your value with a percentage symbol, you can structure your code like this:

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

Important Note About Memory Leaks

When you inject the Application context directly into your ViewModel using Hilt, you might receive a warning about potential memory leaks. However, tests using Android Profiler have shown no actual leaks occurring in practice, so don’t be alarmed. It's just a standard warning to be aware of.

Conclusion

By following the guidelines laid out in this post, you can confidently retrieve and display string resources in your ViewModel without running into errors. Whether you choose to implement AndroidViewModel or reliance on Hilt, the methodology will ensure that you are using the correct application context, ultimately allowing your app to run smoothly and efficiently. Happy coding!