CODEWITHSUNDEEP
reactjssymfonywebpack
Jérémy Dutheil
Jérémy Dutheil

Reputation: 6137

Intégrating React into Symfony (Webpack Encore) : ReferenceError : React is not defined

I'm trying to add React to an existing Symfony4 project with Webpack Encore ; I followed guides around, and that looked pretty straightforward... But I'm keep getting an exception saying "React is not defined", can't do anything.

Here are the files :

webpack.config.js

    var Encore = require('@symfony/webpack-encore')

// Manually configure the runtime environment if not already configured yet by the "encore" command.
// It's useful when you use tools that rely on webpack.config.js file.
if (!Encore.isRuntimeEnvironmentConfigured()) {
  Encore.configureRuntimeEnvironment(process.env.NODE_ENV || 'dev')
}

Encore
  // directory where compiled assets will be stored
  .setOutputPath('public/build/')
  // public path used by the web server to access the output path
  .setPublicPath('/build')
  // only needed for CDN's or sub-directory deploy
  //.setManifestKeyPrefix('build/')

  // React
  .enableReactPreset()

  .addEntry('react-app', './assets/react-app/index.js')

  

  // When enabled, Webpack "splits" your files into smaller pieces for greater optimization.
  .splitEntryChunks()

  // will require an extra script tag for runtime.js
  // but, you probably want this, unless you're building a single-page app
  .enableSingleRuntimeChunk()

  /*
   * FEATURE CONFIG
   *
   * Enable & configure other features below. For a full
   * list of features, see:
   * https://symfony.com/doc/current/frontend.html#adding-more-features
   */
  .cleanupOutputBeforeBuild()
  .enableBuildNotifications()
  .enableSourceMaps(!Encore.isProduction())
  // enables hashed filenames (e.g. app.abc123.css)
  .enableVersioning(Encore.isProduction())

  // enables @babel/preset-env polyfills
  .configureBabelPresetEnv((config) => {
    config.useBuiltIns = 'usage'
    config.corejs = 3
  })

  .configureBabel(function (babelConfig) {
    babelConfig.plugins = [
      '@babel/plugin-proposal-object-rest-spread',
      '@babel/plugin-proposal-class-properties',
      '@babel/plugin-transform-runtime',
    ]
  })


module.exports = Encore.getWebpackConfig()

index.js

import ReactDOM from 'react-dom'
import App from './App'

ReactDOM.render(
  <React.StrictMode>
    <App />
  </React.StrictMode>,
  document.getElementById('root')
)

in base.html.twig

{{ encore_entry_script_tags( 'react-app') }}

Am I missing something ?

(Btw, I have a in my template to call React)

Keep getting this error :

Uncaught ReferenceError: React is not defined
    at Module../assets/react-app/index.js (index.js:5)
    at __webpack_require__ (bootstrap:79)
    at checkDeferredModules (bootstrap:45)
    at Array.webpackJsonpCallback [as push] (bootstrap:32)
    at react-app.js:1

EDIT: if I had 'window.React = React' right after the import (as I saw in other topics), it works... Is it a normal thing ?

Upvotes: 1

Views: 1139

Answers (1)

hamzae
hamzae

Reputation: 91

you need to import react in your index.js file like this :

import React from 'react'

Upvotes: 2

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