my general coffeescript/javascript style

application_helper.rb

  #embed this in your body tag
  # %body{body_data}
  
  def body_data
    {
      :"data-controller" => params[:controller], 
      :"data-action" => params[:action], 
      :"data-id" => params[:id], 
      :"data-parent-controller" => parent_controller,
      :"data-parent-id" => params["#{parent_controller.to_s.singularize}_id".to_sym] 
    }
  end

initialize.js.coffee

#app/assets/javascripts/initialize.js.coffee
window.APP = 
  common: ->
    console.log "common base function"

jQuery ->
  controller = $("body").data("controller")
  action = $("body").data("action")
  app = window.APP

  fn = app['common']
  if typeof(fn) == 'function'
    fn.call()

  if app[controller]
    fnc = app[controller]['common']
    if typeof(fnc) == 'function'
      fnc.call()

      fna = app[controller][action]
      if typeof(fna) == 'function'
        fna.call()

products.js.coffee

#app/assets/javascripts/page_objects/products.js.coffee
$.extend window.APP,
  products:
    common: ->
      #console.log "common functions"
    index: ->
      #console.log "index action functions"
    show: ->
      new GalleryColorBox()
      
class GalleryColorBox
  constructor: ->
    $("a.gallery").colorbox(rel: 'variants')

    $("div.product-variants").delegate("a.change-picture", "click", (e) ->
      e.preventDefault()
      base = $(e.target).parents("div.variant-panel")
      key = base.data("key")
      product = $("body").data("id")
      console.log product, key