Installation

1. Add the gems

Add ReactiveComponent and its dependencies to your Gemfile:

gem "reactive_component"

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/controllers/reactive_renderer_controller"

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

Other bundlers

If you are using esbuild, Vite, Rspack, or another bundler, install the JavaScript package from npm. Install it under the reactive_component alias, matching the gem version. The controller imports its helpers by that name, the same way the importmap pins it:

npm install reactive_component@npm:@lluzak/reactive_component@0.9.1
# or
pnpm add reactive_component@npm:@lluzak/reactive_component@0.9.1

Either command writes the alias to your package.json. You can also add it by hand and run npm install or pnpm install:

"dependencies": {
  "reactive_component": "npm:@lluzak/reactive_component@0.9.1"
}

No bundler configuration is needed. Register the controller as shown above:

import ReactiveRendererController from "reactive_component/controllers/reactive_renderer_controller"

The package lists @hotwired/stimulus and @rails/actioncable as peer dependencies, so install them too if your app doesn’t have them yet.

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
prism	~> 1.0	Parsing the ERB-compiled Ruby; the extractor and emitter walk its tree
erubi	~> 1.11	ERB to Ruby