Stimulus Introduction


The front page of the Stimulus web site contains the following example:

// hello_controller.js
import { Controller } from "stimulus"

export default class extends Controller {
  static targets = [ "name", "output" ]

  greet() {
    this.outputTarget.textContent =
      `Hello, ${this.nameTarget.value}!`

The equivalent code using the Ruby2JS Stimulus filter:

class HelloController < Stimulus::Controller
  def greet()
    outputTarget.textContent =
      "Hello, #{nameTarget.value}!"



Notably, there are no imports, no exports, no static targets, and no this.. All you need to do is follow the naming conventions and drop the file in the right location and everything will JustWork™.

Try it out! Enter your name and press the Greet button. Now make a change to the controller - perhaps change the exclamation point to a question mark. Press the Greet button again.

Elevator Pitch

The Ruby2JS Stimulus filter is for people who both:

Technical Background

JavaScript programmers are familiar with the concept of transpilers such as Babel and CoffeeScript, which take inputs in one language and convert it to JavaScript.

Ruby programmers are familiar with the concept of Domain Specific Languages (DSLs) that expresses framework and library concepts using Ruby syntax.

Rails programmers are familiar with conventions over configuration, whereby where you place logic and how you name things affects how things work.

The Ruby2JS Stimulus filter is a hybrid approach pulling all three together. You write your code in Ruby, interacting with Stimulus Targets, Values, and Classes. This code is transpiled to JavaScript and delivered to the browser. As a result, you can seamlessly interact with JavaScript and the browsers Document Object Model (DOM).

Next: Installation