$ scope.variable在指令控制器中没有改变

Question

我正在为$ scope.retryId分配一个值，if语句正在触发。但是，$ scope.retryId似乎正在重置其未定义的先前值。这是coffeescript：

retryModule.directive 'retryCall', () ->
  restrict: 'EA'
  scope:
    retryId: '@'
    showUrl: '@'
    clearErrorsOnViewChange: '@'
    clearSuccessOnViewChange: '@'
    showSuccessfulRequests: '@'
    showFailedRequests: '@'
    taglineForError: '@'
    taglineForSuccess: '@'
    defaultErrorMessage: '@'
    defaultSuccessMessage: '@'
  template: """
       .... Template Stuff .....
        """
  # Directive Controller
  # =====
  # Handles the status report of $http requests
  # - Shows failed requests and counts down until next automatic request attempt
  # - Shows successful, non-GET responses
  # - Allows user to manually retry failed requests
  controller: [
    '$scope',
    '$http',
    '$rootScope',
    '$location',
    '$interval',
    'RetryCall',
    ($scope, $http, $rootScope, $location, $interval, RetryCall) ->
      # _path: gives us our current url
      _path = $location.path()
      $scope.work = 'hii'
      # Set defaults for all options
      if !$scope.retryId?
        # This will fire, but it will go back to undefined
        $scope.retryId = true