My vim-rails config to define EmberJS commands, example command: :Rjmodel. More info in: http://robots.thoughtbot.com/post/50107717967/extending-rails-vim-with-custom-commands

projections.json

{
  "app/assets/javascripts/models/*.js": {
    "command": "jmodel",
    "alternate": "spec/javascripts/models/%s_spec.js",
    "template": "App.%S = DS.Model.extend"
  },  
  
  "app/assets/javascripts/controllers/*_controller.js": {
    "command": "jcontroller",
    "alternate": "spec/javascripts/controllers/%s_spec.js",
    "template": "App.%SController = Ember.ObjectController.extend"
  },
 
  "app/assets/javascripts/views/*_view.js": {
    "command": "jview",
    "alternate": "spec/javascripts/views/%s_spec.js",
    "related": "app/assets/javascripts/templates/%s.hbs",
    "template": "%SView = Ember.View.extend"
  },
 
  "app/assets/javascripts/router.js": {
    "command": "jrouter"
  },
 
  "app/assets/javascripts/routes/*_route.js": {
    "command": "jroute",
    "alternate": "spec/javascripts/routes/%s_spec.js",
    "template": "App.%SRoute = Ember.Route.extend"
  },
 
  "spec/javascripts/*_spec.js": {
    "command": "jspec",
    "alternate": "app/assets/javascripts/%s.js"
  },
 
  "app/assets/javascripts/templates/*.hbs": {
    "command": "template",
    "alternate": "app/assets/javascripts/views/%s.js"
  }
}