elm-rails makes it easy to use Elm modules in your Ruby on Rails applications. This project was heavily inspired by react-rails.

This gem is tested against Ruby 2.2 and 2.3, and Rails versions 4.2.7 and 5.0. It may work on other versions, and if you want to open a PR adding tests against those versions they would be welcome.

1. Add elm-rails to your Gemfile and run bundle install

   gem "elm-rails"

2. Create a new directory to house all Elm modules

   mkdir app/assets/elm

3. Update .gitignore to ignore elm files

   /elm-stuff
   

1. Define your elm modules in the app/assets/elm directory.

   app/assets/elm/Hello.elm

   module Hello exposing (..)
   
   import Html exposing (text)
   
   port noun : String
   
   main =
     text ("Hello " ++ noun)

2. Open your app/assets/javascripts/application.js and require your Hello.elm.

//= require Hello

3. Use the view helper to insert your component into your view. Pass port values as a Hash.

   <h1>This is an Elm component!</h1>
   <%= elm_embed('Elm.Hello', { noun: 'World!' }) %>

4. That's it!

By default, elm-rails will use the version of elm-make available in your system path. If you wish, you may configure this in an initializer: config/initializers/elm_rails.rb erb Elm::Rails.elm_make_path = "bin/elm-make"