Script to set the value of an input field populated using a browser's autocomplete feature

read-auto-complete.coffee

angular.module 'myModule', []
.factory 'inputsWatcher', ( $interval ) ->
  INTERVAL_MS = 500
  handlers = []

  execHandlers = ->
    for handler in handlers
      handler()

  registerInput: (handler) ->
    if handlers.push handler
      $interval execHandlers, INTERVAL_MS

  unregisterInput: (handler) ->
    handlers.splice handlers.indexOf(handler), 1
    if handlers.length is 0 then $interval.cancel promise
    
.config ($provide) ->
  inputDecoration =  ($delegate, inputsWatcher) ->
    directive = $delegate[0]
    link = directive.link
    handler = null

    linkDecoration = (scope, element, attrs, ngModel) ->
      # By default model.$viewValue is equals to undefined
      if attrs.type is "checkbox"
        handler = ->
          value = element[0].checked
          # By default element is not checked
          if value and ngModel.$viewValue isnt value then ngModel.$setViewValue value

      else if attrs.type is "radio"
        handler = ->
          value = attrs.value
          # By default element is not checked
          if element[0].checked and ngModel.$viewValue isnt value then ngModel.$setViewValue value

      else
        handler = ->
          value = element.val()
          # By default value is an empty string
          if (ngModel.$viewValue isnt undefined or value isnt "") and ngModel.$viewValue isnt value then ngModel.$setViewValue value

      inputsWatcher.registerInput handler

      scope.$on "$destroy", ->
        inputsWatcher.unregisterInput handler

      # Exec original `link()`
      link.$apply this, [].slice.call(arguments, 0)

    # Decorate `link()` don't work for `inputDirective` (why?)
    # directive.link = linkDecoration;
    # So use `compile()` instead
    directive.compile = (element, attrs, transclude) ->
      linkDecoration

    delete directive.link
    $delegate

  $provide.decorator "inputDirective", inputDecoration
  $provide.decorator "textareaDirective", inputDecoration