usePromise

A React hook that makes it easy to handle the state of promises.

NPM Package

🚀 Demo

Storybook demo

💻 Getting Started

npm install @cadbox1/use-promise

or

yarn add @cadbox1/use-promise

Then use it like this

import React, { useEffect } from "react";
import { usePromise } from "cadbox1/use-promise";

const Page = () => {
    const { pending, fulfilled, rejected, value, reason, call } = usePromise({
        promiseFunction: async () => {
            const value = await Promise.resolve(Math.random() * 10);
            return value;
        }
    });

    useEffect(() => {
        call();
    }, []);

    return <button onClick={() => call()} disabled={pending}>Current value is: {value}</button>
}

API

usePromise has full typescript types.

The usePromise hook takes two arguments:

• promiseFunction - a function that returns a Promise, usually an async function.
• updateableRequest - an UpdateableState object that can be used to update an external state. Rarely used.

usePromise will then return an object with the following properties:

• pending - a boolean that is true when a the promiseFunction has been called but not resolved or rejected yet.
• rejected - a boolean that is true when the promise has been rejected, even when another call is pending. It will return false if another call resolves.
• fulfilled - a boolean that is true when the promise has been resolved, even when another call is pending. It will return false if another call rejects.
• value - the value resolved by the promiseFunction. It is not cleared by a pending call, only by a rejection.
• reason - the value rejected by the promiseFunction. It is not cleared by a pending call, only by a resolution.
• status - an PromiseState enum consolidating the state of the request into a single value. Useful for useEffect dependencies.

It retains the resolved and rejected values while pending which works well for tables and retrying form requests.

For example, you can show a page of results in a table and show a pending state while the next page loads.

🔮 Future Development

• Add a property similar to pending that only shows after about 200ms so short requests are less jerky.

🔨 Package Development

• yarn Install dependencies
• yarn storybook Develop in Storybook
• yarn test Run tests
• npm run version-minor Deploy to npm
• yarn clean Remove temporary assets

🔧 Tools

This package was setup with tsdx.