import owl.carousel from webpack

Question

I am new to the F2E world. I just created a web application using create-react-app. (https://github.com/facebookincubator/create-react-app)

I wanted to import owl.carousel into my projects, so that I followed the guide of NPM (https://www.npmjs.com/package/owl.carousel) ,which of the syntax is:

import $ from 'jquery';
import 'imports?jQuery=jquery!owl.carousel';

but the debugger console indicated the error :

Unexpected '!' in 'imports?jQuery=jquery!owl.carousel'. Do not use      import syntax to configure webpack loaders import/no-webpack-loader-syntax

I tried another syntax:

import owlCarousel from 'owl.carousel' 

and the error would be:

Uncaught TypeError: Cannot read property 'fn' of undefined

Could somebody help me figure out what happened? thanks.

Update: my webpack loader settings:

loaders: [
  // Process JS with Babel.
  {
    test: /\.(js|jsx)$/,
    include: paths.appSrc,
    loader: 'babel-loader',
    query: {
      cacheDirectory: findCacheDir({
        name: 'react-scripts'
      })
    }
  },
  {
    test: /\.css$/,
    loader: 'style!css?importLoaders=1!postcss'
  },
  {
    test: /\.json$/,
    loader: 'json'
  },
  {
    test: /\.(ico|jpg|jpeg|png|gif|eot|otf|webp|svg|ttf|woff|woff2)(\?.*)?$/,
    loader: 'file',
    query: {
      name: 'static/media/[name].[hash:8].[ext]'
    }
  },
  {
    test: /\.(mp4|webm|wav|mp3|m4a|aac|oga)(\?.*)?$/,
    loader: 'url',
    query: {
      limit: 10000,
      name: 'static/media/[name].[hash:8].[ext]'
    }
  }
]

my component code:

import React, { Component } from 'react';
import './App.css';
import './css/style.css';
import './css/bootstrap.min.css';
import './css/owl.carousel.css';
import FruitSelector from './containers/fruit_Selector';
import FruitDetail  from './containers/fruit_Detail';
import $ from 'jquery';
import 'owl.carousel';

class App extends Component {
render() {
$(document).ready(function(){

  $(".content-slider").owlCarousel({
      slideSpeed: 350,
      singleItem: true,
      autoHeight: true,
      navigation: true,
      navigationText: ["<i class='fa fa-angle-left'></i>", "<i class='fa fa-angle-right'></i>"]
  });
});

return (
  <div className="App">
  <div className="row">
    <div className="col-sm-4 col-md-3 sidebar">
      <FruitSelector/>
    </div>
    <div className="col col-md-8">
        <FruitDetail/>
    </div>
    </div>
  </div>
);
}
}

export default App;

my webpack.config.dev.js plugin setting:

plugins: [

new InterpolateHtmlPlugin({
  PUBLIC_URL: publicUrl
}),

new HtmlWebpackPlugin({
  inject: true,
  template: paths.appHtml,
}),
new webpack.DefinePlugin(env),
new webpack.HotModuleReplacementPlugin(),
// Watcher doesn't work well if you mistype casing in a path so we use
// a plugin that prints an error when you attempt to do this.
// See https://github.com/facebookincubator/create-react-app/issues/240
new CaseSensitivePathsPlugin(),
// If you require a missing module and then `npm install` it, you still have
// to restart the development server for Webpack to discover it. This plugin
// makes the discovery automatic so you don't have to restart.
// See https://github.com/facebookincubator/create-react-app/issues/186
new WatchMissingNodeModulesPlugin(paths.appNodeModules),
new webpack.ProvidePlugin({
      $: "jquery",
      jQuery: "jquery",
      "window.jQuery": "jquery"
  })]

the error pops out:

App.js:71 Uncaught TypeError: (0 , _jquery2.default)(...).owlCarousel is not a function(…)

Answer 1

Remove plugin which blocks import syntax

Problem is with import syntax which is not default webpack syntax. You have installed in Your project https://github.com/benmosher/eslint-plugin-import/blob/master/docs/rules/no-webpack-loader-syntax.md to block it, for sure it is part of react-create-app. Please remove it to enable this syntax.

Owl.carousel needs jQuery library imported inside it because it uses $ variable, so this is problem and it is why webpack-loader-syntax must be removed.

If we try to import owl in standard way then jQuery is not defined there ( every file in webpack has own scope ), so it will throw an error:

Uncaught TypeError: Cannot read property 'fn' of undefined

---

( Alternative )Use shimming module

If removing plugin is problem then You can try to add jQuery to every module with usage it as shimming module - https://webpack.github.io/docs/shimming-modules.html.

In webpack config it will look like:

module.exports = {
  plugins: [
    new webpack.ProvidePlugin({
    $: "jquery",
    jQuery: "jquery",
    "window.jQuery": "jquery"
    })
]
//other config vars
};

And just add it by:

import 'owl.carousel'

Answer 2

I had a issue with same error "Cannot read property 'fn' of undefined", but making sure the Jquery reference was first, fixed it for me.

<!-- Webjar References -->
  <script src="webjars/jquery/3.3.1/jquery.min.js"></script>
  <script src="webjars/bootstrap/4.3.1/js/bootstrap.min.js"></script>
  <link href="webjars/bootstrap/4.3.1/css/bootstrap.min.css"
        rel="stylesheet">