react-hooks-worker
React custom hooks for web workers.
Introduction
Web Workers are another thread from the main thread in browsers.
We can run heavy computation in a separate thread so that
users don't feel slowing down.
React provides a reactive system.
This library hides the async nature of Web Workers with React custom hooks.
Results returned by Web Workers are stored in a React local state.
Developers can implement a worker as:
- sync function
- async function
- sync generator function
- async generator function
Install
npm install react-hooks-worker
Usage
slow_fib.worker.js:
import { exposeWorker } from 'react-hooks-worker';
const fib = i => (i <= 1 ? i : fib(i - 1) + fib(i - 2));
exposeWorker(fib);
app.js:
import React from 'react';
import { useWorker } from 'react-hooks-worker';
const createWorker = () => new Worker(new URL('./slow_fib.worker', import.meta.url));
const CalcFib = ({ count }) => {
const { result, error } = useWorker(createWorker, count);
if (error) return <div>Error: {error}</div>;
return <div>Result: {result}</div>;
};
const App = () => (
<div>
<CalcFib count={5} />
</div>
);
Recipes
Pending status
The communication between main thread and worker thread is not RPC model.
It can be one input to return multiple outputs, or
multiple inputs to get one output.
Handling pending or stale status is left for library users.
Refer #44
for a recipe for isStale
.
API
exposeWorker
expose worker
You can expose any function that returns:
- A value
- A promise
- An iterable
- An async iterable
Parameters
func
function (data: any): any
Examples
import { exposeWorker } from 'react-hooks-worker';
const fib = (i) => (i <= 1 ? i : fib(i - 1) + fib(i - 2));
exposeWorker(fib);
useWorker
use worker
The createWorker function should be stable to keep the worker running.
If it's referentially changed, it will create a new worker and terminate the old one.
Parameters
createWorker
function (): Workerinput
any
Examples
import { useWorker } from 'react-hooks-worker';
const createWorker = () => new Worker(new URL('./slow_fib.worker', import.meta.url));
const CalcFib = ({ count }) => {
const { result, error } = useWorker(createWorker, count);
if (error) return <div>Error: {error}</div>;
return <div>Result: {result}</div>;
};
Examples
The examples folder contains working examples.
You can run one of them with
PORT=8080 npm run examples:01_minimal
and open http://localhost:8080 in your web browser.
Blogs