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hyper-react is an Opal Ruby wrapper of React.js library.

It lets you write reactive UI components, with Ruby's elegance using the tried and true React.js engine. :heart:

Visit ruby-hyperloop.io for the full story.

Important: react.rb, reactive-ruby and reactrb gems are deprecated. See UPGRADING for details.


Install the gem, or load the js library

  1. Add gem 'hyper-react' to your Gemfile
  2. Or gem install hyper-react
  3. Or install (or load via cdn) from reactrb-express.js

For gem installation it is highly recommended to read the getting started and installation guides at ruby-hyperloop.io.

Quick Overview

A component is a plain ruby class with a #render method defined.

class HelloMessage
  def render
    React.create_element("div") { "Hello World!" }

puts React.render_to_static_markup(React.create_element(HelloMessage))

# => '<div>Hello World!</div>'


You can simply include React::Component to get the power of a complete DSL to generate html markup, event handlers and it also provides a full set of class macros to define states, parameters, and lifecycle callbacks.

As events occur, components update their state, which causes them to rerender, and perhaps pass new parameters to lower level components, thus causing them to rerender.

require 'opal'
require 'browser/interval'
require 'opal-jquery'
require 'react/react-source'
require 'hyper-react'
require 'react/top_level_render'

class HelloWorld < React::Component::Base
  param :time, type: Time
  render do
    p do
      span { "Hello, " }
      input(type: :text, placeholder: "Your Name Here")
      span { "! It is #{params.time}"}

every(1) do
  Element["#example"].render do
    HelloWorld(time: Time.now)

hyper-react components are isomorphic (or univeral) meaning they can run on the server as well as the client.

hyper-react integrates well with Rails, Sinatra, and simple static sites, and can be added to existing web pages very easily.

Under the hood the actual work is effeciently done by the React.js engine.

Why ?

  • Single Language: Use Ruby everywhere, no JS, markup languages, or JSX
  • Powerful DSL: Describe HTML and event handlers with a minimum of fuss
  • Ruby Goodness: Use all the features of Ruby to create reusable, maintainable UI code
  • React Simplicity: Nothing is taken away from the React.js model
  • Enhanced Features: Enhanced parameter and state management and other new features
  • Plays well with Others: Works with other frameworks, React.js components, Rails, Sinatra and static web pages

Problems, Questions, Issues


Version 0.10.x will not be 100% backward compatible with 0.3.0 (react.rb) or 0.7.x (reactive-ruby).

Please let us know either at Gitter.im or via an issue if you have specific concerns with the upgrade from 0.3.0 to 0.10.x.


git clone the project.

To play with some live examples, refer to https://github.com/ruby-hyperloop/reactrb-examples.

Note that these are very simple examples, for the purpose of showing how to configure the gem in various server environments. For more examples and information see ruby-hyperloop.io.


  1. Run bundle exec rake test_app to generate a dummy test app.
  2. bundle exec appraisal install to generate separate gemfiles for different environments.
  3. bundle exec appraisal opal-0.10-react-15 rake to run test for opal-0.10 & react-v0.15.


This project is still in early stage, so discussion, bug reports and PRs are really welcome :wink:.


In short, hyper-react is available under the MIT license. See the LICENSE file for more info.