Calling Javascript per controller and its action

application.html.slim

doctype html
html
  head
    meta charset='UTF-8'
    meta name='viewport' content='width=device-width, initial-scale=1.0'
    meta http-equiv='x-ua-compatible' content='ie=edge'
    title APP_NAME
    = stylesheet_link_tag 'application', media: 'all', 'data-turbolinks-track' => true
    
    - controller.js_assets.each do |name|
      = javascript_include_tag name, 'data-turbolinks-track' => true
    
    = csrf_meta_tags

  body data=body_data class=body_css_class

application.js

//= require ./controllers/base

application_helper.rb

  def body_data
    data = { view: "#{controller_path}##{action_name}" }
    data[:debug] = 'true' if Rails.env.development?
    data
  end

  def body_css_class
    controller_name = controller_path.underscore.tr('/', '-')
    "#{controller_name} #{controller_name}-#{css_action_name}"
  end

base.js.coffee

# app/controllers/base.js.coffee

window.Controllers = {} # namespace for controller loaders
controllers = {} # holds the loaded controllers for re-use when working with Turbolinks
debug = undefined

# helper to bind an event handler and optionally call it immediately
Controllers.bind = (call, $el, selector, evt, handler) ->
  if call
    for dt in $el
      for ct in $(dt).find(selector)
        handler({ currentTarget: ct, delegateTarget: dt })
  $el.on(evt, selector, handler)
  return
  
  r
  

# run the controller-action for the current view
$(document).on 'ready page:load', ->
  $body = $(document.body)
  debug = $body.attr('data-debug')
  run($body.attr('data-view'))
  return
  
run = (view) ->
  console.log('view:', view) if debug
  return if !view
  [controller, action] = view.split('#')
  if (loader = Controllers[controller])
    c = (controllers[controller] ||= new (loader()))
    return if c.before_action && c.before_action(action) == false
    return if c[action]       && c[action](action)       == false
    return if c.after_action  && c.after_action(action)  == false
  return

base_controller.rb

# app/controllers/admin/base_controller.rb

class Admin::BaseController < ApplicationController

  JS_ASSETS = %W( application users ).freeze
  
end

users.js.coffee

#app/controllers/admin/users.js.coffee

Controllers['admin/users'] = -> class AdminUsers
  index: (action) ->
    ...
  new: (action) ->
    ...
  create: (action) ->
    ...
  edit: (action) ->
    ...
  update: (action) ->
    ...