Page specific javascript on Rails

page.js

//Based on https://www.driftingruby.com/episodes/page-specific-javascript-in-ruby-on-rails#comments
// Usage:
// if(!page.isControllerAndAction('users', 'index')) return;

var Page, bind = function(fn, me){ return function(){ return fn.apply(me, arguments); }; };

Page = (function() {
  function Page() {
    this.action = bind(this.action, this);
    this.controller = bind(this.controller, this);
  }

  Page.prototype.controller = function() {
    return $('meta[name=psj]').attr('controller');
  };

  Page.prototype.action = function() {
    return $('meta[name=psj]').attr('action');
  };

  Page.prototype.isController = function(controller) {
    return controller === this.controller()
  };

  Page.prototype.isAction = function(action) {
    return action === this.action()
  };

  Page.prototype.isControllerAndAction = function(controller, action) {
    return this.isController(controller) && this.isAction(action)
  };

  return Page;
})();

this.page = new Page;