Axios & Express

(Express) server.js

const app = require('express')()

app.use((req, res, next) => {
    res.header("Access-Control-Allow-Origin", "*");
    res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
    res.header("Content-Type", "application/json")
    next();
});

app.get('/', (req, res) => {
    res.json({
        content: '<h1>Hello World</h1>'
    })
})

app.listen(4000)

(React) index.js

import React, { Component } from 'react'
import { hydrate } from 'react-dom'
import ReactHtmlParser from 'react-html-parser'
import axios from 'axios'

class App extends Component {
    constructor() {
        super()
        this.state = {
            content: '',
        }
    }
    componentDidMount() {
        axios.get('http://localhost:4000', {
            headers: {
                'Content-Type': 'application/json',
                "Access-Control-Allow-Origin": "*"
            }
        }).then(res => this.setState({ content: res.data.content}))
    }
    render() {
        return (
            <div>
                {ReactHtmlParser(this.state.content)}
            </div>
        )
    }
}

hydrate(
    <App/>, document.getElementById('root')
)