


Hey everyone!
I’ve been working on a lightweight React hook that I called useAsync that mimics some of the essential features of React Query (like fetching, caching, retries, etc.) but in a more compact, easily customizable package. Below is a quick breakdown of how it works internally, referencing the relevant code sections. If you want to see the entire code, head over to the repo:
Full Source Code on GitHub.
The hook is also available on npm as api-refetch.
Why Making My Own Hook?
While React Query and SWR are both great libraries, I wanted a more hands-on approach for a few reasons:
Lightweight Footprint
While React Query and SWR are feature-rich, they can be relatively large (React Query ~2.2 MB, SWR ~620 kB). api-refetch is around 250 kB, making it ideal for smaller apps where bundle size is a big concern. This hook as meant to be installed as a dependency of another library (Intlayer). As a result, the size of the solution was an important consideration.Easy to Customize & Optimize
I needed some specific capabilities—like storing/fetching data from local storage and managing parallel requests using a straightforward approach.
By cloning the repo or copying the code directly into your project, you can strip out any unwanted features and keep only what you need. This not only reduces bundle size but also minimizes unnecessary re-renders and increase, giving you a leaner, more performant solution tailored to your specific requirements.No Required Provider
I wanted to avoid Context Provider to make the hook global, and keep it's usage as simple as possible. So I made a version of the hooke based on a Zustand store (see example bellow).Learning Exercise
Building an async library from scratch is an excellent way to understand concurrency, caching, and state management internals.
In short, rolling my own hook was a chance to hone in on precisely the features I need (and skip the ones I don’t) while keeping the library small and easy to understand.
Covered Features
The React hook manage:
- Fetching & State Management: Handles loading, error, success, and fetched states.
- Caching & Storage: Optionally caches data (via React states or Zustand under the hood) and offers local storage support.
- Retries & Revalidation: Configurable retry limits and automatic revalidation intervals.
- Activation & Invalidation: Automatically activates and invalidates queries depending on other queries' or states. Example: automatically fetch some data when the user logs in. And invalidate it when the user logs out.
- Parallel Component Mount Fetching: Prevents multiple simultaneous requests for the same resource when multiple components mount at once.
How the Code Works
Below are the key points in api-refetch and short references to the relevant parts of the code in useAsync.tsx.
1. Fetching and Handling Parallel Mounting
- Code Snippet:
// This map stores any in-progress Promise to avoid sending parallel requests // for the same resource across multiple components. const pendingPromises = new Map(); const fetch: T = async (...args) => { // Check if a request with the same key + args is already running if (pendingPromises.has(keyWithArgs)) { return pendingPromises.get(keyWithArgs); } // Otherwise, store a new Promise and execute const promise = (async () => { setQueryState(keyWithArgs, { isLoading: true }); // ...perform fetch here... })(); // Keep it in the map until it resolves or rejects pendingPromises.set(keyWithArgs, promise); return await promise; };
- Explanation: Here, we store any ongoing fetch in a pendingPromises map. When two components try to fetch the same resource simultaneously (by having the same keyWithArgs), the second one just reuses the ongoing request instead of making a duplicate network call.
2. Revalidation
- Code Snippet:
// Handle periodic revalidation if caching is enabled useEffect( () => { if (!revalidationEnabled || revalidateTime { fetch(...storedArgsRef.current); }, revalidateTime); return () => clearTimeout(timeout); }, [ /* dependencies */ ] );
- Explanation: Whenever you enable revalidation, api-refetch checks if the cached data is older than a specified revalidateTime. If it is, the data is automatically re-fetched in the background to keep your UI in sync without extra manual triggers.
3. Retry Logic
- Code Snippet:
useEffect( () => { const isRetryEnabled = errorCount > 0 && retryLimit > 0; const isRetryLimitReached = errorCount > retryLimit; if (!isEnabled || !enabled) return; // Hook is disabled if (!isRetryEnabled) return; // Retry is disabled if (isRetryLimitReached) return; // Retry limit has been reached if (!(cacheEnabled || storeEnabled)) return; // Useless to retry if caching is disabled if (isLoading) return; // Fetch is already in progress if (isSuccess) return; // Hook has already fetched successfully const timeout = setTimeout(() => { fetch(...storedArgsRef.current); }, retryTime); return () => clearTimeout(timeout); }, [ /* dependencies */ ] );
- Explanation: On error, the hook counts how many failed attempts have occurred. If it’s still below the retryLimit, it automatically waits retryTime milliseconds before trying again. This process continues until data is successfully fetched or the retry limit is reached.
4. Auto-Fetch
- Code Snippet:
// Auto-fetch data on hook mount if autoFetch is true useEffect( () => { if (!autoFetch) return; // Auto-fetch is disabled if (!isEnabled || !enabled) return; // Hook is disabled if (isFetched && !isInvalidated) return; // Hook have already fetched or invalidated if (isLoading) return; // Fetch is already in progress fetch(...storedArgsRef.current); }, [ /* dependencies */ ] );
- Explanation: With autoFetch set to true, the hook will automatically run the async function as soon as the component mounts—perfect for “fire-and-forget” scenarios where you always want the data on load.
See the Full Source on GitHub
Check out the complete code, which includes local storage logic, query invalidation, and more here:
- Full Source Code
Feel free to give it a try, report issues, or contribute if you’re interested. Any feedback is much appreciated!
Example of use
Installation
Copy the code or code the (repo)[https://github.com/aymericzip/api-refetch]
Or
// This map stores any in-progress Promise to avoid sending parallel requests // for the same resource across multiple components. const pendingPromises = new Map(); const fetch: T = async (...args) => { // Check if a request with the same key + args is already running if (pendingPromises.has(keyWithArgs)) { return pendingPromises.get(keyWithArgs); } // Otherwise, store a new Promise and execute const promise = (async () => { setQueryState(keyWithArgs, { isLoading: true }); // ...perform fetch here... })(); // Keep it in the map until it resolves or rejects pendingPromises.set(keyWithArgs, promise); return await promise; };
Quick Example
// Handle periodic revalidation if caching is enabled useEffect( () => { if (!revalidationEnabled || revalidateTime { fetch(...storedArgsRef.current); }, revalidateTime); return () => clearTimeout(timeout); }, [ /* dependencies */ ] );
That’s it! Give it a try, and let me know how it goes. Feedback, questions, or contributions are more than welcome on GitHub.
GitHub: api-refetch
Happy coding!
The above is the detailed content of Showcase of a Lightweight Hook for Async Data Fetching & Caching in React. For more information, please follow other related articles on the PHP Chinese website!

Detailed explanation of JavaScript string replacement method and FAQ This article will explore two ways to replace string characters in JavaScript: internal JavaScript code and internal HTML for web pages. Replace string inside JavaScript code The most direct way is to use the replace() method: str = str.replace("find","replace"); This method replaces only the first match. To replace all matches, use a regular expression and add the global flag g: str = str.replace(/fi

This tutorial shows you how to integrate a custom Google Search API into your blog or website, offering a more refined search experience than standard WordPress theme search functions. It's surprisingly easy! You'll be able to restrict searches to y

So here you are, ready to learn all about this thing called AJAX. But, what exactly is it? The term AJAX refers to a loose grouping of technologies that are used to create dynamic, interactive web content. The term AJAX, originally coined by Jesse J

This article series was rewritten in mid 2017 with up-to-date information and fresh examples. In this JSON example, we will look at how we can store simple values in a file using JSON format. Using the key-value pair notation, we can store any kind

Leverage jQuery for Effortless Web Page Layouts: 8 Essential Plugins jQuery simplifies web page layout significantly. This article highlights eight powerful jQuery plugins that streamline the process, particularly useful for manual website creation

Core points This in JavaScript usually refers to an object that "owns" the method, but it depends on how the function is called. When there is no current object, this refers to the global object. In a web browser, it is represented by window. When calling a function, this maintains the global object; but when calling an object constructor or any of its methods, this refers to an instance of the object. You can change the context of this using methods such as call(), apply(), and bind(). These methods call the function using the given this value and parameters. JavaScript is an excellent programming language. A few years ago, this sentence was

jQuery is a great JavaScript framework. However, as with any library, sometimes it’s necessary to get under the hood to discover what’s going on. Perhaps it’s because you’re tracing a bug or are just curious about how jQuery achieves a particular UI

This post compiles helpful cheat sheets, reference guides, quick recipes, and code snippets for Android, Blackberry, and iPhone app development. No developer should be without them! Touch Gesture Reference Guide (PDF) A valuable resource for desig


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),

SublimeText3 Linux new version
SublimeText3 Linux latest version

Notepad++7.3.1
Easy-to-use and free code editor

PhpStorm Mac version
The latest (2018.2.1) professional PHP integrated development tool

Dreamweaver CS6
Visual web development tools
