ptb-fe/store/with-redux-store.js

import React from 'react';
import configureStore from './store.js';
import { readState, saveState } from './persisted.store.cookies.js';

const isServer = typeof window === 'undefined';
const __NEXT_REDUX_STORE__ = '__NEXT_REDUX_STORE__';

function getOrCreateStore(initialState) {
    // Always make a new store if server, otherwise state is shared between requests
    if (isServer) {
        return configureStore(initialState);
    }

    // Create store if unavailable on the client and set it on the window object
    if (!window[__NEXT_REDUX_STORE__]) {
        window[__NEXT_REDUX_STORE__] = configureStore(initialState);
    }

    return window[__NEXT_REDUX_STORE__];
}

const AppFn = App => {
    return class AppWithRedux extends React.Component {
        static async getInitialProps(appContext) {
            let initialState = appContext.ctx.req
                ? readState(appContext.ctx.req.headers.cookie)
                : {};

            // Get or Create the store with `undefined` as initialState
            // This allows you to set a custom default initialState
            const reduxStore = getOrCreateStore(initialState);

            // Provide the store to getInitialProps of pages
            appContext.ctx.reduxStore = reduxStore;

            let appProps = {};
            if (typeof App.getInitialProps === 'function') {
                appProps = await App.getInitialProps(appContext);
            }

            return {
                ...appProps,
                initialReduxState: reduxStore.getState()
            };
        }

        constructor(props) {
            super(props);
            this.reduxStore = getOrCreateStore(props.initialReduxState);
        }

        render() {
            return <App {...this.props} reduxStore={this.reduxStore} />;
        }
    };
};

export default AppFn;