JavaScript and Initializers

Forem has two JavaScript codebases.

One is located in the directory app/assets/javascripts and contains plain JavaScript (mostly ES5+) being served using Sprockets which packages static assets.

Webpacker manages the other one, which you can read more about in this guide.

This source code is not transpiled, only packaged and minified, and will be limited to whatever flavor of JavaScript can run on the user's web browser.

app/assets/javascripts/application.js contains the manifest JavaScript file which is included globally in the primary template, app/views/layouts/application.html.erb.

application.js automatically includes all JS files via the statement:

//= require_tree .

One JS file in particular, app/assets/javascripts/initializePage.js, bootstraps the majority of the functionality. You will notice, within this file, that major sections of the websites are bootstrapped, for example:

initializeBaseTracking();
initializeCommentsPage();
initEditorResize();
initLeaveEditorWarning();
initializeArticleReactions();
initNotifications();
initializeSplitTestTracking();

All the "initializers" are in /app/assets/javascripts/initializers.