What is the correct way to use wow.js in Rails 6 with webpacker?

Question

I am trying to use wow.js with my Ruby on Rails 6.1.3.2 project. I have installed wowjs with Yarn and I see it in my node_modules folder.

I have imported wowjs into my application app/javascript/packs/application.js

import WOW from 'wowjs';
require("wowjs/css/libs/animate.css") 

I have a script.js file located at this path: app/javascript/script.js and initiates WOW

    wow = new WOW({
        animateClass: 'animated',
        offset: 100
    });
    wow.init();

script.js is imported into app/javascript/packs/application.rb after wowjs is imported like this:

import WOW from 'wowjs';
require("wowjs/css/libs/animate.css")
import "scripts.js"

I keep getting the following error in the console:

scripts.js:514 Uncaught ReferenceError: WOW is not defined
at Object.<anonymous> (scripts.js:514)
at Object../app/javascript/scripts.js (scripts.js:897)
at __webpack_require__ (bootstrap:63)
at Module../app/javascript/packs/application.js (application.js:1)
at __webpack_require__ (bootstrap:63)
at bootstrap:198
at bootstrap:198

I have other modules that I have installed in a similar manner that are not throwing errors. I'd like to understand what the "rails way" of doing this is. Thanks in advance for your assistance.

Answer 1

The answer to this question was ultimately the following:

Move the import statements from application.js to scripts.js where the modules were being used:

import "splitting/dist/splitting.css";
import "splitting/dist/splitting-cells.css";
import Splitting from "splitting";

I was missing the declaration of 'wow' as a 'var'. So I added 'var' to the script.js like this:

var wow = new WOW({
    animateClass: 'animated',
    offset: 100
});
wow.init();

The key lesson for me was that the import statements needed to be at the top of the script that was consuming the modules. I had assumed that just by virtue of them being imported into application.js that was enough to make them available to all scripts. Perhaps that was a newbie lesson. Many thanks to @rossta for some important guidance. I'm looking forward to his soon coming The Webpacker Course.

Answer 2

Install jquery, wowjs by yarn, add this line to app/javascript/packs/application.js:

window.WOW = require('wowjs').WOW;

Embed wow css to project by add to app/assets/stylesheets/application.scss this line:

 @import "wowjs/css/libs/animate";

And finish by create this view example app/views/pages/home.html.erb:

Welcome to project railstrace !
<section class="wow slideInLeft" data-wow-duration="2s" data-wow-delay="5s">ABC</section>
<section class="wow slideInRight" data-wow-offset="10"  data-wow-iteration="10">DEF</section>

<script>
  new WOW({live: false}).init()
</script>

Note: If set new WOW({live: false}).init() will remove this warning: MutationObserver is not supported by your browser.

Enjoy!