readme.md

redux-broadcast-actions

A tiny middleware to broadcast your redux actions using the Broadcast Channel API. It can sync actions between tabs, and even between all processes of a Browser Extension (background, workers, content scripts, popup, custom pages). Then you just need to plug all your pure reducers onto all your processes, and you have a state that is synced as simply as possible.

How to install

Install with npm or yarn

npm install --save @getstation/redux-broadcast-actions
# or
yarn add @getstation/redux-broadcast-actions

How to use

In all the processes where you need the actions to be dispatched and received, instanciate this middlware:

import { createStore, applyMiddleware } from 'redux';
import { createBroadcastActionsMiddleware } from '@getstation/redux-broadcast-actions';

const store = createStore(rootReducer, {}, applyMiddleware(
  // broadcast actions to other processes
  createBroadcastActionsMiddleware({
    // name given to BroadcastChannel. Can also be a BroadcastChannel instance
    channel: 'redux_broadcast_actions',
  })
));

Then whenever you execute store.dispatch(...) in any process, all others are receiving the exact same action.

Share initial state

If one of your process acts as a source of truth (server) and other processes (clients) need to ask for its current state to be initialized:

Server

import { createStore, applyMiddleware } from 'redux';
import {
  createBroadcastActionsMiddleware,
  createSendInitialStateMiddleware
} from '@getstation/redux-broadcast-actions';

const store = createStore(rootReducer, {}, applyMiddleware(
  // this middleware listens for clients asking for initial state
  createSendInitialStateMiddleware(),
  createBroadcastActionsMiddleware(),
));

Client

import { createStore, applyMiddleware, combineReducers } from 'redux';
import {
  createBroadcastActionsMiddleware,
  createGetInitialStateMiddleware,
  initialStateReducer
} from '@getstation/redux-broadcast-actions';

// add initialStateReducer to the list of reducers
const store = createStore(combineReducers(initialStateReducer, rootReducer), {}, applyMiddleware(
  // ask server for initial state
  // ⚠️ should be the first middleware
  createGetInitialStateMiddleware(),
  createBroadcastActionsMiddleware(),
));

I do not want to broadcast one or more actions

You can do that. First, by default some events of some libs are not broadcasted (redux-form, redux-persist, and some others, check shouldForward function for details). If you do not want to broadcast one of your action, you can leverage the meta property of your action like this:

dispatch({
  type: 'myAction',
  meta: {
    // this tells the middleware to not broadcast this action
    local: true,
  }
})