Скачать или смотреть Solving the Redux Does Not Change Values Issue

Discover how to resolve the common issue of Redux not updating values in your React Native application with step-by-step instructions and code examples.
---
This video is based on the question https://stackoverflow.com/q/70772839/ asked by the user 'Nicole Lopez' ( https://stackoverflow.com/u/14906718/ ) and on the answer https://stackoverflow.com/a/70775424/ provided by the user 'Nicole Lopez' ( https://stackoverflow.com/u/14906718/ ) 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: Redux does not change values

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.
---
Understanding Redux and the Value Update Problem

When working with Redux in React Native, it's common for developers to encounter issues where the state doesn't update as expected. One of such frustrating problems is when the values in your Redux store do not change, despite dispatching actions to update them. This can be a major roadblock for those new to Redux, and understanding the root cause is key to finding the solution.

In this guide, we'll dive into a specific case of a user who faced this issue and provide a detailed, step-by-step solution that anyone can follow. We'll explore the structure of Redux actions, reducers, and the proper usage of hooks in functional components to resolve the problem effectively.

Problem Overview

The user described a scenario where they were testing Redux and noticed that log outputs consistently showed the initial value instead of the expected updated value after dispatching an action. Here’s a breakdown of how to troubleshoot and solve this problem.

The Code in Question

The user provided parts of their code, including actions, reducers, and the component where state is being used. Key points to note are:

Redux Action Definition:

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

Redux Reducer:

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

Login Component:
This component was where the user was trying to log the value:

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

The Diagnosis

From the initial analysis, the code seems mostly correct. However, the user was missing one crucial aspect of working with Redux in functional components: dispatching actions correctly from the function component.

Key Mistake

The user did not initialize the dispatch function or use it to call the action that would update the Redux state. The following changes were necessary for state to update properly.

The Solution

Step 1: Import the Necessary Hook

The first change involves importing useDispatch from Redux and initializing it in the component. This allows the component to dispatch actions to the Redux store.

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

Step 2: Dispatch the Action

Using useEffect, you can dispatch the action when the component mounts or when certain dependencies change.

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

Step 3: Console Logging the Result

Finally, ensure that when you log the result, it reflects the updated state from Redux:

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

Complete Code Example

Here’s how the complete LoginScreen component looks with the changes implemented:

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

Conclusion

By ensuring that you properly dispatch actions using useDispatch, you can effectively update your Redux state and reflect those changes in your components. Redux can be daunting for newcomers, but by following the proper structure and methods, these issues can be resolved smoothly.

If you find yourself stuck, always return to verifying that actions are being dispatched and that your reducer is processing those actions as expected. Happy coding!