Ember.js Dynamic Computed Property Builder (based on http://www.thesoftwaresimpleton.com/blog/2013/08/11/dyanamic-cp/ by Paul Cowan)

computed_property_builder.js.coffee

Em.computedPropertyBuilder = (that, name, key, fn) ->
  Em.defineProperty that, name, Em.computed(->
    fn
  ).property "#{key}"

en.yml

messages:
  details:
    company:
      placeholder: 'Please provide company name'
      helpMessage: 'Remember that working just for money is gonna make you frustrated om nom nom!'

i18n_helpers.js.coffee

Em.getMessageFromScope = (scope, key, defaultMessage='') ->
  if Em.typeOf(Em.t scope) is 'string' and key is 'label'
    Em.t scope
  else
    if Em.t(scope)?[key] then Em.t(key, scope: scope) else defaultMessage

some_view.js.coffee

App.SomeView = Em.View.extend
  messages: 'placeholder helpMessage'.w()
  # passed as a param in view init
  scope:    'messages.details.company'

  init: ->
    @buildMessages()
    @_super()

  buildMessages: ->
    @get('messages').forEach (string) =>
      Em.computedPropertyBuilder @, string, 'scope', Em.getMessageFromScope(@get('scope'), string)