Using react redux with next.js

Question

I try to use Redux with next.js starter project and I installed next-redux-wrapper on the project but I'm not sure where is the root file in this project.

I try to follow the tutorial shown on the next-redux-wrapper but had no success. Nothing change.

Please help me with how to add Redux to the project.

Regards.

Answer 1

Next.js uses the App component to initialize pages. You can override it and control the page initialization.

Although this demo is for next.js it should work for nextjs-starter.

install next-redux-wrapper:

npm install --save next-redux-wrapper

Add _app.js file to ./pages directory:

// pages/_app.js
import React from "react";
import {createStore} from "redux";
import {Provider} from "react-redux";
import App, {Container} from "next/app";
import withRedux from "next-redux-wrapper";

const reducer = (state = {foo: ''}, action) => {
    switch (action.type) {
        case 'FOO':
            return {...state, foo: action.payload};
        default:
            return state
    }
};

/**
* @param {object} initialState
* @param {boolean} options.isServer indicates whether it is a server side or client side
* @param {Request} options.req NodeJS Request object (not set when client applies initialState from server)
* @param {Request} options.res NodeJS Request object (not set when client applies initialState from server)
* @param {boolean} options.debug User-defined debug mode param
* @param {string} options.storeKey This key will be used to preserve store in global namespace for safe HMR 
*/
const makeStore = (initialState, options) => {
    return createStore(reducer, initialState);
};

class MyApp extends App {

    static async getInitialProps({Component, ctx}) {

        // we can dispatch from here too
        ctx.store.dispatch({type: 'FOO', payload: 'foo'});

        const pageProps = Component.getInitialProps ? await Component.getInitialProps(ctx) : {};

        return {pageProps};

    }

    render() {
        const {Component, pageProps, store} = this.props;
        return (
            <Container>
                <Provider store={store}>
                    <Component {...pageProps} />
                </Provider>
            </Container>
        );
    }

}

export default withRedux(makeStore)(MyApp);

And then, actual page components can be simply connected: This demo how to connect index.js in pages.

import Link from "next/link";
import React from "react";
import {
  Container,
  Row,
  Col,
  Button,
  Jumbotron,
  ListGroup,
  ListGroupItem
} from "reactstrap";
import Page from "../components/page";
import Layout from "../components/layout";

import { connect } from "react-redux";

class Default extends Page {
  static getInitialProps({ store, isServer, pathname, query }) {
    store.dispatch({ type: "FOO", payload: "foo" }); // component will be able to read from store's state when rendered
    return { custom: "custom" }; // you can pass some custom props to component from here
  }
  render() {
    return (
      <Layout>content...</Layout>
    );
  }
}

export default connect()(Default);

Refer to the documentation for more information: next-redux-wrapper

Answer 2

First i created simple next.js app with "npx create-next-app"

Then I created general redux setup in a folder called "store".

This is the folder structure

And in pages i have created an _app.js. Code inside it is like this-

Please let me know if anyone needs any help with setup...

Answer 3

this question needs update:

"next": "12.1.4",
"next-redux-wrapper": "^7.0.5",
"redux-devtools-extension": "^2.13.9",
"redux-thunk": "^2.4.1"

Create Store

import { createStore, applyMiddleware } from "redux";
import { HYDRATE, createWrapper } from "next-redux-wrapper";
import reducers from "./reducers/reducers";

import thunkMiddleware from "redux-thunk";

// middleware is an array
const bindMiddleware = (middleware) => {
  if (process.env.NODE_ENV !== "production") {
    const { composeWithDevTools } = require("redux-devtools-extension");
    return composeWithDevTools(applyMiddleware(...middleware));
  }
  return applyMiddleware(...middleware);
};
// this is main reducer to handle the hydration
const reducer = (state, action) => {
  // hydration is a process of filling an object with some data
  // this is called when server side request happens
  if (action.type === HYDRATE) {
    const nextState = {
      ...state,
      ...action.payload,
    };
    return nextState;
  } else {
    // whenever we deal with static rendering or client side rendering, this will be the case
    // reducers is the combinedReducers
    return reducers(state, action);
  }
};

const initStore = () => {
  return createStore(reducer, bindMiddleware([thunkMiddleware]));
};

export const wrapper = createWrapper(initStore);

_app.js

import { wrapper } from "../redux/store";

function MyApp({ Component, pageProps }) {
  return <Component {...pageProps} />;
}

export default wrapper.withRedux(MyApp);

Using it with getServerSideProps

// sample action
import { getRooms } from "../redux/actions/roomActions";
import { wrapper } from "../redux/store";

export const getServerSideProps = wrapper.getServerSideProps(
  (store) =>
    // destructuring context obj
    async ({ req, query }) => {
      await store.dispatch(getRooms(req, query.page));
    }
);