Installation

1. Add the gems

Add ReactiveComponent and its dependencies to your Gemfile:

gem "reactive_component"

Caution

ruby2js must be installed from the GitHub HEAD until the required ERB compilation features are released:

gem "ruby2js", github: "ruby2js/ruby2js"

Then install:

bundle install

2. Mount the engine

Add the engine to your config/routes.rb so the server-action endpoint is available:

Rails.application.routes.draw do
  mount ReactiveComponent::Engine => "/reactive_component"

  # ... your other routes
end

This mounts a single POST /reactive_component/actions endpoint used by live_action to execute server-side actions securely.

3. JavaScript setup

importmap-rails (default)

If your application uses importmap-rails, ReactiveComponent automatically registers its import map pins when the engine loads. The engine pins all files under app/javascript/reactive_component so they are available to the asset pipeline.

You need to register the Stimulus controller in your application. In your JavaScript entrypoint (e.g. app/javascript/controllers/index.js), import and register the controller:

import { application } from "controllers/application"
import ReactiveRendererController from "reactive_component/reactive_renderer_controller"

application.register("reactive-renderer", ReactiveRendererController)

Other bundlers

If you are using esbuild, Vite, or another bundler, you can import the controller from the gem’s app/javascript directory. Add the gem’s JavaScript path to your bundler’s configuration and import the controller as shown above.

4. ActionCable

ReactiveComponent requires ActionCable to be configured and running. Make sure your config/cable.yml is set up (Redis is recommended for production) and that ActionCable is mounted in your routes:

config/routes.rb

Rails.application.routes.draw do
  mount ActionCable.server => "/cable"
  mount ReactiveComponent::Engine => "/reactive_component"
end

Dependencies

ReactiveComponent depends on the following gems (declared in the gemspec):

Gem	Version	Purpose
rails	>= 7.1	Framework
view_component	any	Base component library
turbo-rails	any	Stream signing and Turbo integration
ruby2js	GitHub HEAD	ERB-to-JavaScript template compilation
prism	any	Ruby source code parsing for ivar extraction