RailsScript
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.
Installation
Add this line to your application's Gemfile:
gem 'rails_script', '~> 0.6.0'
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 %>
Usage
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
window.App ||= {}
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
window.App ||= {}
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
window.App ||= {}
class App.Base
constructor: ->
@footerRollover()
return this
footerRollover: ->
$(".site-credit a").hoverIntent(
over: ->
$(".site-credit a").html("<div class='maui-logo'></div>")
out: ->
$(".site-credit a").html("SITE CREDIT")
)
In this example we extracted the rollover action into a new function. Doing so will make the class cleaner and easier to maintain as the application grows. Once again note the return this
in the constructor.
Global Functions
Any functions that need to be accessible in the global scope should be defined in global.js.coffee
using the App
namespace. Below is an example of one of our favorite functions that we use to submit a form using AJAX as a JSON request.
# app/assets/javascripts/global.js.coffee
window.App ||= {}
App.remoteSubmission = ($form) ->
$.ajax
url: $form.attr('action')
type: $form.attr('method')
data: $form.serialize()
dataType: 'json'
return
Now you can access this function from anywhere in the application by just calling App.remoteSubmission($('#myForm'))
Utilities
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
window.Utility ||= {}
class Utility.Modal
constructor: ->
return this
Let's add some basic functionality:
# /app/assets/javascripts/utilities/modal.js.coffee
window.Utility ||= {}
class Utility.Modal
isOpen: false
constructor: ($element, $trigger) ->
@element = $element
@trigger = $trigger
@trigger.on 'click', @toggle
return this
toggle: (event) =>
event.preventDefault()
if @isOpen then @close() else @open()
open: =>
@isOpen = true
@element.show()
close: =>
@isOpen = false
@element.fadeOut('fast')
Now, here's how we use the utility from users#show
# app/assets/javascripts/users.js.coffee
window.App ||= {}
class App.Users extends App.Base
show: ->
@galleryModal = new Utility.Modal($('#user-gallery-modal-wrapper'), $('user-gallery-modal-toggle-button'))
Elements
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```
window.Element ||= {}
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
window.App ||= {}
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
window.Element ||= {}
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 RailsScript. 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) =>
return
afterAction: (action) =>
return
index: =>
return
show: =>
return
new: =>
return
edit: =>
return
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
window.App ||= {}
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
private
def set_javascript_vars
to_javascript user: current_user, friends: current_user.friends
end
end
And here's how we print that data to the console on the users#index
action:
# /app/assets/javascripts/users.js.coffee
window.App ||= {}
class App.Users extends App.Base
index: =>
console.log Utility.RailsVars.user
console.log Utility.RailsVars.friends
Events
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.
Contributing
- Fork it ( https://github.com/[my-github-username]/rails_script/fork )
- Create your feature branch (
git checkout -b my-new-feature
) - Commit your changes (
git commit -am 'Add some feature'
) - Push to the branch (
git push origin my-new-feature
) - Create a new Pull Request