laubfall/redux-batched-actions

redux higher order reducer + action to reduce actions under a single subscriber notification

redux-batched-actions

Batching action creator and associated higher order reducer for redux that enables batching subscriber notifications for an array of actions.

npm install --save redux-batched-actions

Usage

import {createStore, applyMiddleware} from 'redux';
import {batchActions, enableBatching, batchDispatchMiddleware} from 'redux-batched-actions';
import {createAction} from 'redux-actions';

const doThing = createAction('DO_THING')
const doOther = createAction('DO_OTHER')

function reducer(state, action) {
	switch (action.type) {
		case 'DO_THING': return 'thing'
		case 'DO_OTHER': return 'other'
		default: return state
	}
}

// Handle bundled actions in reducer
const store = createStore(enableBatching(reducer), initialState)

store.dispatch(batchActions([doThing(), doOther()]))
// OR
store.dispatch(batchActions([doThing(), doOther()], 'DO_BOTH'))

Recipes

Async

Usage for action creators that return objects is trivial, but it also works well with thunks to perform large reductions on multiple asynchronous actions, or actions that rely on external services. For example:

const setLoading = createAction('SET_LOADING')
const setUser = createAction('SET_USER')
const unsetLoading = createAction('UNSET_LOADING')

function login(credentials) {
	return function(dispatch) {
		dispatch(setLoading());

		authenticate(credentials)
			.then(user => {
				dispatch(batchActions([
					setUser(user),
					unsetLoading()
				], 'LOGIN_SUCCESS'))
			})
		})
	}
}

In this example, the subscribers would be notified twice: once when the state is loading, and then again once the user has been loaded.

Middleware integration

You can add a middleware to dispatch each of the bundled actions. This can be used if other middlewares are listening for one of the bundled actions to be dispatched.

const store = createStore(
		reducer,
		initialState,
		applyMiddleware(batchDispatchMiddleware)
)

Note that batchDispatchMiddleware and enableBatching should not be used together as batchDispatchMiddleware calls next on the action it receives, whilst also dispatching each of the bundled actions.

Thanks

Thanks to Dan Abramov for help in Redux best practices and original idea.