redux-batched-dispatch

Redux store enhancer to allow batched dispatch.

Table of Contents

• Installation
• Usage
  • Batch Action
  • Rate Limited Dispatch
  • With Middlewares
• Module Usage
  • ES6 module
  • CommonJS
  • Browser
• Extra API
  • batchAction
  • store.getActionQueue
• Guide
  • Cancel actions in the queue
  • Cancel rate limited dispatch

Installation

yarn:

yarn add redux-batched-dispatch

npm:

npm install --save redux-batched-dispatch

Usage

Batch Action

import { createBatchEnhancer }  from 'redux-batched-dispatch';
import { createStore } from 'redux';

const store = createStore(reducer, createBatchEnhancer());

// Batched dispatch will notify to listeners only once after store updated
store.dispatch([
  { type: 'Hello' },
  { type: 'World' },
]);

Rate Limited Dispatch

import { createBatchEnhancer }  from 'redux-batched-dispatch';
import { createStore } from 'redux';
import throttle from 'lodash.throttle';
import debounce from 'lodash.debounce';

function reducer(state = [], action) {
  switch (action.type) {
    case 'PUSH':
      return [...state, action.value];
    default:
      return state;
  }
}

function push(value) {
  return {
    type: 'PUSH',
    value,
  };
}

const store = createStore(
  reducer,
  createBatchEnhancer({
    // Invoke `dispatch`, but not more than once every 100ms.
    'DISPATCH_THROTTLE': dispatch => throttle(dispatch, 100, { leading: false }),
    // Invoke `dispatch`, debouncing 100ms
    'DISPATCH_DEBOUNCE': dispatch => debounce(dispatch, 100),
  }),
);

store.subscribe(() => {
  console.log(store.getState());
});

setTimeout(() => { store.dispatch(push('T1'), 'DISPATCH_THROTTLE') }, 0);
setTimeout(() => { store.dispatch(push('T2'), 'DISPATCH_THROTTLE') }, 20);
setTimeout(() => { store.dispatch(push('T3'), 'DISPATCH_THROTTLE') }, 40);
setTimeout(() => { store.dispatch(push('T4'), 'DISPATCH_THROTTLE') }, 260);
setTimeout(() => { store.dispatch(push('D1'), 'DISPATCH_DEBOUNCE') }, 0);
setTimeout(() => { store.dispatch(push('D2'), 'DISPATCH_DEBOUNCE') }, 70);
setTimeout(() => { store.dispatch(push('D3'), 'DISPATCH_DEBOUNCE') }, 140);
setTimeout(() => { store.dispatch(push('D4'), 'DISPATCH_DEBOUNCE') }, 300);
  
// stdout1:100ms => ['T1', 'T2', 'T3']
// stdout2:240ms => ['T1', 'T2', 'T3', 'D1', 'D2', 'D3']
// stdout3:360ms => ['T1', 'T2', 'T3', 'D1', 'D2', 'D3', 'T4']
// stdout4:400ms => ['T1', 'T2', 'T3', 'D1', 'D2', 'D3', 'T4', 'D4']

With Middlewares

You can use extra middlewares like redux-thunk, redux-saga, redux-observable, etc..

import { createBatchEnhancer }  from 'redux-batched-dispatch';
import { createStore, applyMiddleware } from 'redux';

const store = createStore(
  reducer,
  createBatchEnhancer(
    applyMiddleware(exampleMiddleware),
    {
      'DISPATCH_DEBOUNCE': dispatch => debounce(dispatch, 100),
    },
  )
);

Module Usage

ES6 module

import { createBatchEnhancer } from 'redux-batched-dispatch';

CommonJS

const { createBatchEnhancer } = require('redux-batched-dispatch');

Browser

Add below <script> tag to the HTML page right before the closing </body> tag

<script src="https://unpkg.com/redux-batched-dispatch@1/dist/index.js" crossorigin></script>

And use global reduxBatchedDispatch variable

Extra API

batchAction

batchAction(action, dispatchType)

You can also use batched dispatch with batchAction

Arguments

action (Array | Object): The redux action

dispatchType (string): The type of dispatch defined when use createBatchEnhancer

Example

import { batchAction }  from 'redux-batched-dispatch';

dispatch(batchAction([
  { type: 'Hello' },
  { type: 'World' },
], 'DISPATCH_THROTTLE'));

It is useful on middleware(ex: redux-saga)

function* createTodo() {
  yield put(batchAction([
    { type: 'Hello' },
    { type: 'World' },
  ], 'DISPATCH_THROTTLE'));
}

store.getActionQueue

store.getActionQueue(dispatchType)

Get queue which contains actions from dispatch. This queue's reference will never change

Arguments

dispatchType (string): The type of dispatch defined when use createBatchEnhancer

Example

const store = createStore(
  reducer,
  createBatchEnhancer({
    'DISPATCH_DEBOUNCE': dispatch => debounce(dispatch, 100),
  })
);

const throttleQueue = store.getActionQueue('DISPATCH_DEBOUNCE');

Guide

Cancel actions in the queue

const throttleQueue = store.getActionQueue('DISPATCH_DEBOUNCE');

// Clear all actions
throttleQueue.length = 0;

// Remove last action
throttleQueue.pop();

// Remove second action
throttleQueue.splice(1, 1);

Cancel rate limited dispatch

import { createBatchEnhancer }  from 'redux-batched-dispatch';
import { createStore } from 'redux';
import throttle from 'lodash.throttle';

let throttledDispatch;

const store = createStore(
  reducer,
  createBatchEnhancer({
    'DISPATCH_THROTTLE': dispatch => {
      throttledDispatch = throttle(dispatch, 100);
      return throttledDispatch;
    }
  }),
);

$(window).on('popstate', throttledDispatch.cancel);

Even if cancel the throttledDispatch, there are still actions in queue If want to clear the queue, see the section Cancel actions in the queue