AngularJS Form Helper

form_helper.js.coffee

angular.module('myApp').factory 'FormHelper', [->
  class FormHelper
    constructor: (scope, object, formName) ->
      @scope = scope
      @formName = formName
      @object = -> @scope[object]
      scope.$watch "#{formName}.$pristine", (pristine) =>
        @unsaved = !pristine
        @saved = false unless pristine
      scope.$watch "#{formName}.$valid", (valid) =>
        @setValid(valid)

    ngForm: => @scope[@formName]

    setValid: (valid) =>
      @valid = valid
      @invalid = !valid

    setUnsaved: =>
      @saved = false
      @unsaved = true
      @ngForm.$setDirty()

    onRemoteSuccess: =>
      @clearNetworkState()
      @saved = true
      @unsaved = false
      @ngForm().$setPristine()

    onRemoteError: =>
      @clearNetworkState()
      @unsaved = true
      # can assign errors from server here
      delete @object().errors
      @setValid(false)

    onNetworkError: (error) =>
      @submitting = false
      @submitError = "#{error.status} error"

    clearNetworkState: =>
      @submitting = false
      @submitError = false

  FormHelper
]

This looks like an interesting/useful pattern. Do you have an example handy showing how you might integrate it with a controller?