RailsScript - A Rails-centric, object oriented, featherweight framework for writing CoffeeScript
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RailsScript is a Rails-centric, object oriented, featherweight framework for writing CoffeeScript. It is optimized for the Rails Asset Pipeline and is compatible with TurboLinks. Using Rails controller names and actions to call JavaScript, it has never been easier to write clean, concise, and maintainable page specific JavaScript.

Upgrading to V2

To migrate from version 0.x to 1.x, please see the wiki; https://github.com/gemgento/rails_script/wiki/v2-Migration


Add this line to your application's Gemfile:

gem 'rails_script', '~> 2.0'

And then execute:

$ bundle

After bundling you need to run the initial installation generator:

$ rails g rails_script:install

After the generator finishes, you will be prompted to add helper call to your application layout. The generated code is responsible for initializing and calling the action specific JavaScript. This helper should be called before the closing body tag.

<%= include_rails_script %>

NOTE: Your JS files needed have been included before include_rails_script. In other words, you still need <%= javascript_include_tag "application" %> in your application layout.

After including the view helper in your application layout, you will need to require the RailsScript javascript library inside your application.js or application.coffee file before the require_tree . line.

if using javascript (app/assets/javascripts/application.js):

// * other app specific js require lines 

//= require rails_script
//= require_tree .

if using coffeescript (app/assets/javascripts/application.coffee):

# * other app specific js require lines 

#= require rails_script
#= require_tree .


Page (Action) Specific JavaScript

Your JavaScript class is named after your Controller and there is a method for each Controller action. Whenever you generate a Controller, the CoffeeScript file that is generated will define the new JavaScript class and the basic REST actions. The example below would print 'users#show' in the console for the Users#show action.

# app/assets/javascripts/users.js.coffee

class App.Users extends App.Base

   show: =>
      console.log 'users#show'

Controller Specific JavaScript

Executing some JavaScript to run on all controller actions is just a matter of adding it to the beforeAction or afterAction function. beforeAction is run before all controller action functions and afterAction is run after all controller action functions. The before and after action functions have an optional argument action which is a string containing the current action name. The example below would print 'before ACTION action' and 'after ACTION action' for each Users controller action.

# app/assets/javascripts/users.js.coffee

class App.Users extends App.Base

  beforeAction: (action) =>
    console.log "before #{action} action"
  afterAction: (action) =>
    console.log "after #{action} action"

Application Wide JavaScript

Running some JavaScript on every page of an Application is a common need. For example, we may want to create a site credit rollover in the footer of every page.

# app/assets/javascripts/base.js.coffee

class App.Base

  constructor: ->
    return this
  footerRollover: ->
    $(".site-credit a").hoverIntent(
      over: ->
        $(".site-credit a").html("<div class='maui-logo'></div>")
      out: ->
        $(".site-credit a").html("SITE CREDIT")

In this example we extracted the rollover action into a new function. Doing so will make the class cleaner and easier to maintain as the application grows. Once again note the return this in the constructor.

Global Functions

Any functions that need to be accessible in the global scope should be defined in global.js.coffee using the App namespace. Below is an example of one of our favorite functions that we use to submit a form using AJAX as a JSON request.

# app/assets/javascripts/global.js.coffee

App.remoteSubmission = ($form) ->
  return $.ajax
    url: $form.attr('action')
    type: $form.attr('method')
    data: $form.serialize()
    dataType: 'json'

Now you can access this function from anywhere in the application by just calling App.remoteSubmission($('#myForm'))


A Utility is a class that will be used to create similar functionality in many areas of the application. A good example of this is a Modal, which could appear multiple times on the same page. So, let's encapsulate this functionality in a highly reusable class.

First, generate the Utility

$ rails g rails_script:utility Modal

This will create the following in /app/assets/javascripts/utilities/modal.js.coffee:

# /app/assets/javascripts/utilities/modal.js.coffee

class Utility.Modal
    constructor: ->
        return this

Let's add some basic functionality:

# /app/assets/javascripts/utilities/modal.js.coffee

class Utility.Modal
    isOpen: false
    constructor: ($element, $trigger) ->
        @element = $element
        @trigger = $trigger
        @trigger.on 'click', @toggle
        return this
    toggle: (event) =>
        if @isOpen then @close() else @open()
    open: =>
        @isOpen = true
    close: =>
        @isOpen = false

Now, here's how we use the utility from users#show

# app/assets/javascripts/users.js.coffee

class App.Users extends App.Base

   show: ->
        @galleryModal = new Utility.Modal($('#user-gallery-modal-wrapper'), $('user-gallery-modal-toggle-button'))


An Element is a class that describes the functionality of a one off element in the application. A Main Menu is a good example of this since there is usually only a single Main Menu.

First generate the Element

$ rails g rails_script:element MainMenu

This will create the following in /app/assets/javascripts/elements/main_menu.js.coffee

# /app/assets/javascripts/elements/main_menu.js.coffee```

class Element.MainMenu

    constructor: ->
        return this

We can now add all the logic for the main menu in a separate class and call it on every page like so:

# app/assets/javascripts/base.js.coffee

class App.Base

  constructor: ->
    App.mainMenu = new Element.MainMenu()
    return this

Element Inheritance

Inheritance is another key tool for reusability. Let's say our Element.MainMenu opens and closes in the same way as the Utility.Modal. Well then MainMenu should just extend Modal, this can be accomplished from the generator:

$ rails g rails:script MainMenu Modal

Which generates:

# /app/assets/javascripts/elements/main_menu.js.coffee

class Element.MainMenu extends Utility.Modal

    constructor: ->
        return this

Inheritance from the generator can only come from a Utility class. Any class you wish to extend should be created as a Utility. The installer adds the line //= require_tree ./utilities before loading tree to handle this. If you have a utility that extends a utility, then make sure the extended utility is loaded first by explicitly requiring it before //= require_tree ./utilities.

Custom Controllers

When a new controller is generated, the JavaScript asset file will be generated with App. However, if you need to manually generate a RailsScript controller you can use:

$ rails g rails_script:controller Some::NewController

Since the above example includes a namespace, it would generate:

# app/assets/javascripts/some/new_controller.js.coffee

window.App ||= {}
class App.SomeNewController extends App.Base

  beforeAction: (action) =>
  afterAction: (action) =>

  index: =>

  show: =>

  new: =>

  edit: =>

None of the pre-defined functions are necessary, you can remove the ones you don't need.

Generic Classes

To generate a generic class that isn't a Utility, Element or Controller, just use the following:

$ rails g rails_script:class My::ClassName

Which generates:

# /app/assets/javascripts/my/class_name.js.coffee

class App.MyClassName
    constructor: ->
        return this

Passing Rails Variables

To pass data from Rails to JavaScript, just call to_javascript along with a hash of your data. This is then converted to a JSON object with to_javascript.to_json and can be accessed with Utility.RailsVars. The to_javascript helper may be called from multiple points in the application, all data is merged together.

Here's an example where to_javascript is used in a before_filter to pass the current user and their friends:

# /app/controllers/application_controller.rb

class ApplicationController
    before_filter :set_javascript_vars
    def set_javascript_vars
        to_javascript user: current_user, friends: current_user.friends

And here's how we print that data to the console on the users#index action:

# /app/assets/javascripts/users.js.coffee

class App.Users extends App.Base

    index: =>
        console.log Utility.RailsVars.user
        console.log Utility.RailsVars.friends


Since Turbolinks doesn't refresh the page and only replaces the body, event listeners defined on window and document carry between page loads. To avoid these event listeners stacking, RailsScript will destroy all event listeners on window and document that have a blank namespace, i.e. $(window).on 'scroll', myHandler. If you need an event handler to persist between page changes, then define a namespace, i.e. $(window).on 'scroll.namespace', myHandler.

Page Transitions

Full page transitions are super easy with RailsScript and Turbolinks. Checkout the wiki for more information on how to add these to your RailsScript application, https://github.com/gemgento/rails_script/wiki/Turbolinks-Page-Transitions.


  1. Fork it ( https://github.com/[my-github-username]/rails_script/fork )
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Commit your changes (git commit -am 'Add some feature')
  4. Push to the branch (git push origin my-new-feature)
  5. Create a new Pull Request