https://github.com/redux-utilities/redux-promise

FSA-compliant promise middleware for Redux.
https://github.com/redux-utilities/redux-promise

Last synced: 21 days ago
JSON representation

FSA-compliant promise middleware for Redux.

• Host: GitHub
• URL: https://github.com/redux-utilities/redux-promise
• Owner: redux-utilities
• License: mit
• Created: 2015-07-02T02:01:07.000Z (over 9 years ago)
• Default Branch: master
• Last Pushed: 2023-01-21T15:40:28.000Z (almost 2 years ago)
• Last Synced: 2024-05-20T00:41:09.276Z (6 months ago)
• Language: JavaScript
• Homepage:
• Size: 671 KB
• Stars: 2,670
• Watchers: 42
• Forks: 134
• Open Issues: 42
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

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README

        
# redux-promise

[![build status](https://img.shields.io/travis/redux-utilities/redux-promise/master.svg)](https://travis-ci.org/redux-utilities/redux-promise)

[![codecov](https://codecov.io/gh/redux-utilities/redux-promise/branch/master/graph/badge.svg)](https://codecov.io/gh/redux-utilities/redux-promise)

[![npm version](https://img.shields.io/npm/v/redux-promise.svg)](https://www.npmjs.com/package/redux-promise)

[![npm monthly downloads](https://img.shields.io/npm/dm/redux-promise.svg)](https://www.npmjs.com/package/redux-promise)

[FSA](https://github.com/redux-utilities/flux-standard-action)-compliant promise [middleware](https://redux.js.org/advanced/middleware) for Redux.

```js

npm install --save redux-promise

```

## Usage

```js

import promiseMiddleware from 'redux-promise';

```

The default export is a middleware function. If it receives a promise, it will dispatch the resolved value of the promise. It will not dispatch anything if the promise rejects.

If it receives an Flux Standard Action whose `payload` is a promise, it will either

* dispatch a copy of the action with the resolved value of the promise, and set `status` to `success`.

* dispatch a copy of the action with the rejected value of the promise, and set `status` to `error`.

The middleware returns a promise to the caller so that it can wait for the operation to finish before continuing. This is especially useful for server-side rendering. If you find that a promise is not being returned, ensure that all middleware before it in the chain is also returning its `next()` call to the caller.

## Using in combination with redux-actions

Because it supports FSA actions, you can use redux-promise in combination with [redux-actions](https://github.com/redux-utilities/redux-actions).

### Example: Async action creators

This works just like in Flummox:

```js

createAction('FETCH_THING', async id => {

  const result = await somePromise;

  return result.someValue;

});

```

Unlike Flummox, it will not perform a dispatch at the beginning of the operation, only at the end. We're still looking into the [best way to deal with optimistic updates](https://github.com/redux-utilities/flux-standard-action/issues/7). If you have a suggestion, let me know.

### Example: Integrating with a web API module

Say you have an API module that sends requests to a server. This is a common pattern in Flux apps. Assuming your module supports promises, it's really easy to create action creators that wrap around your API:

```js

import { WebAPI } from '../utils/WebAPI';

export const getThing = createAction('GET_THING', WebAPI.getThing);

export const createThing = createAction('POST_THING', WebAPI.createThing);

export const updateThing = createAction('UPDATE_THING', WebAPI.updateThing);

export const deleteThing = createAction('DELETE_THING', WebAPI.deleteThing);

```

(You'll probably notice how this could be simplified even further using something like lodash's `mapValues()`.)