Скачать или смотреть Fixing the Background Color Issue in React Native Star Rating Component

Learn how to effectively change background colors in a React Native star rating component using state management and a few simple tweaks to your code!
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This video is based on the question https://stackoverflow.com/q/75150424/ asked by the user 'Vigilante' ( https://stackoverflow.com/u/17704142/ ) and on the answer https://stackoverflow.com/a/75150626/ provided by the user 'abdemirza' ( https://stackoverflow.com/u/10798040/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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Fixing the Background Color Issue in React Native Star Rating Component

When building a star rating component in React Native, a common requirement is to dynamically change the background color of stars based on user interactions. A situation arises when the background color does not reflect the expected changes even after clicks, leading to frustration. If you are facing a similar challenge with your star rating component where the stars remain gray notwithstanding user clicks, this guide is here to help!

The Problem

You want to display a star rating system where:

All stars are gray by default.

When a star is clicked, it and all previous stars should turn green, indicating they are selected.

However, after implementing your functionality, the expected behavior does not happen, even though your console logs indicate that changes are being registered.

This hints at an issue within your state management approach in React, particularly how you update the state of your star array.

Analyzing the Current Code

Let’s take a look at your existing code snippet:

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

Identifying the Issue

The key problem in this code lies in directly modifying the holdStars array. In React, state should be treated as immutable. When you modify the existing state object, React does not recognize that a change has occurred, and thus, it doesn't trigger a re-render.

The Solution

You can solve this problem by creating a copy of the holdStars array before making modifications. Here's how you can implement this:

Step-by-Step Solution

Clone the Array: Use the spread operator to make a shallow copy of the holdStars array.

Modify the Copied Array: Iterate through the cloned array to change the selected property based on user interaction.

Update State: Finally, call setHoldStars with the modified clone.

Here's the updated handleStarClicked function:

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

Conclusion

By ensuring that you create a new array instead of modifying the existing state directly, you will allow React to recognize changes and re-render your component accordingly. This simple adjustment will solve the issue of the background not changing when stars are clicked.

Now, when you click on the stars, the background color should change as intended, providing a clear visual feedback based on the rating selected.

Final Thoughts

State management in React can sometimes feel tricky, but following best practices and understanding immutability can easily resolve many common issues. I hope this guide helps you in your journey to building interactive and visually appealing React Native apps.

If you have further questions or need additional assistance, feel free to reach out in the comments below!