This package allows you to subscribe to changes in any part of Redux state.

npm install redux-subscriber --save

store.js

import {createStore} from 'redux';
import initSubscriber from 'redux-subscriber';

const store = createStore(...);

// "initSubscriber" returns "subscribe" function, so you can use it
const subscribe = initSubscriber(store);

somewhere-else.js

// or you can just import "subscribe" function from the package
import {subscribe} from 'redux-subscriber';

const unsubscribe = subscribe('user.messages.count', state => {
  // do something
});

// if you want to stop listening to changes
unsubscribe();

• https://github.com/ivantsov/yandex-mail-notifier-chrome - real app that uses redux-subscriber

• store - instance of Redux store.

Returns subscribe function.

• key - string which specified the part of state (e.g. user.message.count) to listen to.
• callbackFunction - function which will be called when the part of state has changed. New state is passed as a parameter.

Returns unsubscribe function which can be called to unsubscribe from changes.