angularJS中的表单重置失败？

Question

On Angular 1.3.15我有以下控制器功能：

smartIdApp.controller('SavePersonalCtrl', ['$scope', '$location', 'IPVService', 'PersonalModel', 'RoutingService','IdentityService',
    function SavePersonalCtrl($scope, $location, IPVService, PersonalModel, RoutingService, IdentityService) {
        $scope.submit = function() {
            console.log('SavePersonalCtrl.submit()');

      // Duplicate and cache Identity data
      var identity = IdentityService.identity;
      identity.push(angular.copy($scope.personalData));

        if ($scope.personalForm.birthname.$viewValue === "Yes") {
          $location.path(PATH_DOB);
        } else {
          var today = new Date().getTime();
          var viewYear = $scope.personalData.birthNameYear;
          var viewMonth = $scope.personalData.birthnameMonth;
          if (daysBetween(today, viewYear, viewMonth, 1) > NAME_VALIDITY_DAYS) {
            $location.path(PATH_DOB);
          } else {
            $scope.personalData = {};
            $scope.personalForm.$setPristine();
            console.log($scope.personalForm.birthNameYear.$viewValue + " " + $scope.personalData);
            $location.path(PATH_NAMES);

          }
        }
        };
    }
]);

应该清除personalData并将personalForm设置为pristine的语句似乎没有效果。记录说：

InitPersonalCtrl()
controllers-personal.js:22 SavePersonalCtrl.submit()
controllers-personal.js:40 2015 [object Object]

为什么这不起作用？