Universal JavaScript Config Vars

config.js

// /app/config.js

class Config {

  constructor() {
    this.data = {};
  }

  setData(data) {
    this.data = {...this.data, ...data};
  }

  get(field) {
    return this.data[field];
  }

};

export default new Config();



// /server/index.js

import appConfig from '../app/config';

appConfig.setData({
  cdnBaseUrl: process.env.CDN_BASE_URL
});



// /server/components/html.jsx

import config from '../../app/config';

const serializedConfig = serialize(config.data);
const scriptHtml = `window.CONFIG_DATA=${serializedConfig};`;

<script dangerouslySetInnerHTML={{__html: scriptHtml}} />



// /client/index.js

import config from '../app/config';

const configData = window.CONFIG_DATA;
config.setData(configData);



// anywhere/else.js

import config from './app/config';

config.get('cdnBaseUrl'); // http://cdn.sm.com/...