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Using the FileReader API to preview images in React

Blog post from LogRocket

Post Details
Company
Date Published
Author
Joseph Mawa
Word Count
2,305
Language
-
Hacker News Points
-
Summary

The article provides a comprehensive guide on how to implement image preview functionality in a React application using the FileReader API. It begins by explaining the significance of image preview features in web applications, which help ensure that users upload images of the correct type, quality, and size. The article details the process of setting up file upload functionality using an input element of type file, with instructions on handling both single and multiple image previews. It highlights the use of the FileReader API for asynchronously reading image files and updating the state with base64-encoded data URLs to render image previews. The author emphasizes the importance of checking MIME types for security purposes and discusses the need for cleanup in the useEffect hook to prevent memory leaks, especially when components unmount or rerender before the reading process is complete. The article concludes by encouraging readers to explore image preview implementation in React and offers insights into handling image previews both singly and in batches.