React Custom Hook: useAsync — Sergey Leschev на vc.ru

In this article series, we embark on a journey through the realm of custom React hooks, discovering their immense potential for elevating your development projects. Our focus today is on the "useAsync" hook, one of the many carefully crafted hooks available in the collection of React custom hooks.

Github: https://github.com/sergeyleschev/react-custom-hooks

import { useCallback, useEffect, useState } from "react" export default function useAsync(callback, dependencies = []) { const [loading, setLoading] = useState(true) const [error, setError] = useState() const [value, setValue] = useState() const callbackMemoized = useCallback(() => { setLoading(true) setError(undefined) setValue(undefined) callback() .then(setValue) .catch(setError) .finally(() => setLoading(false)) }, dependencies) useEffect(() => { callbackMemoized() }, [callbackMemoized]) return { loading, error, value } }

The useAsync hook takes in a callback function that performs the asynchronous operation and an optional array of dependencies. It returns an object with three properties: loading, error, and value. The loading property indicates whether the operation is currently in progress, while the error property holds any error messages encountered during the process. Finally, the value property contains the resolved value of the asynchronous operation.

One of the significant advantages of useAsync is its ability to memoize the callback function using useCallback. This ensures that the callback is only recreated when the dependencies change, preventing unnecessary re-renders and optimizing performance. Additionally, the hook employs the useState and useEffect hooks to manage the loading state and invoke the memoized callback function when necessary.

import useAsync from "./useAsync" export default function AsyncComponent() { const { loading, error, value } = useAsync(() => { return new Promise((resolve, reject) => { const success = false setTimeout(() => { success ? resolve("Hi") : reject("Error") }, 1000) }) }) return ( <div> <div>Loading: {loading.toString()}</div> <div>{error}</div> <div>{value}</div> </div> ) }

useAsync can be employed in a wide range of scenarios. Whether you're fetching data from an API, performing computations, or handling form submissions, this custom hook simplifies the management of asynchronous operations throughout your React components. Its flexibility and ease of use make it a valuable addition to any React project.

By utilizing useAsync, you can streamline your codebase, enhance reusability, and maintain a consistent and reliable user experience. Give it a try in your next React project and witness the power of simplified asynchronous operations.

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