react-use-promise

React hook for handling promises.

Disclaimer

While this works and is an interesting use of hooks, it might be a better idea to use Suspense when dealing with promises.

Suspense isn't still fully released, but you can start using it with React.lazy.

Installation

Using npm:

$ npm install --save react-use-promise

Using yarn:

$ yarn add react-use-promise

Since this module uses React's new Hooks feature, to try this out you'll need to install at least version 16.8.0 of react and react-dom:

$ yarn add react@^16.8.0 react-dom@^16.8.0

Usage

import React, { useMemo } from 'react';
import usePromise from 'react-use-promise';

function Example() {
  const [result, error, state] = usePromise(
    () => new Promise(resolve => {
      setTimeout(() => resolve('foo'), 2000);
    }),
    []
  );

  return (
    <div>
      <p>{state}</p>
      <p>{result || error}</p>
    </div>
  );
}

API

usePromise<Result, Error>(
  Promise<Result, Error> | () => Promise<Result, Error>,
  Array<any>
): [
  Result,
  Error,
  'pending' | 'resolved' | 'rejected'
]

Receives a promise or a function that returns a promise and returns an array with the promise's result, error and state. The state is a string that can have one of three values: 'pending', 'resolved' or 'rejected'.

Note: You'll need to pass the inputs array to usePromise, otherwise this will try to resolve the promise on every render. For example:

const [response, error] = usePromise(
  () => fetch(url),
  [url]
);

This will only call fetch again when the url changes.

If you only want to resolve the promise once, pass an empty array, like this:

const [result, error] = usePromise(
  () => Notification.requestPermission(),
  []
);

Development

Clone the repo and install the dependencies by running yarn on the project's root directory (or npm install, if you don't have yarn installed).

Tests can be run with yarn test (or npm test) and there's an example application that can be run with yarn example (or npm run example).

Contributing

Please feel free to submit any issues or pull requests.

License

MIT