fix(timepicker): garbage collect parent watchers

- Garbage collect parent $$watchers on $destroy

Closes #5277

Author: wesleycho

src/timepicker/test/timepicker.spec.js

@@ -2191,4 +2191,21 @@ describe('timepicker directive', function() {
       expect(getModelState()).toEqual([14, 40, 25]);
     });
   });
+
+  describe('gc', function() {
+    var $scope;
+    beforeEach(inject(function() {
+      $scope = $rootScope.$new();
+      element = $compile('<uib-timepicker ng-model="time"></uib-timepicker>')($scope);
+      $rootScope.$digest();
+    }));
+
+    it('should clean up watchers', function() {
+      expect($scope.$$watchers.length > 1).toBe(true);
+
+      element.isolateScope().$destroy();
+
+      expect($scope.$$watchers.length).toBe(1);
+    });
+  });
 });

src/timepicker/timepicker.js

@@ -16,8 +16,9 @@ angular.module('ui.bootstrap.timepicker', [])
 
 .controller('UibTimepickerController', ['$scope', '$element', '$attrs', '$parse', '$log', '$locale', 'uibTimepickerConfig', function($scope, $element, $attrs, $parse, $log, $locale, timepickerConfig) {
   var selected = new Date(),
-      ngModelCtrl = { $setViewValue: angular.noop }, // nullModelCtrl
-      meridians = angular.isDefined($attrs.meridians) ? $scope.$parent.$eval($attrs.meridians) : timepickerConfig.meridians || $locale.DATETIME_FORMATS.AMPMS;
+    watchers = [],
+    ngModelCtrl = { $setViewValue: angular.noop }, // nullModelCtrl
+    meridians = angular.isDefined($attrs.meridians) ? $scope.$parent.$eval($attrs.meridians) : timepickerConfig.meridians || $locale.DATETIME_FORMATS.AMPMS;
 
   $scope.tabindex = angular.isDefined($attrs.tabindex) ? $attrs.tabindex : 0;
   $element.removeAttr('tabindex');
@@ -51,35 +52,35 @@ angular.module('ui.bootstrap.timepicker', [])
 
   var hourStep = timepickerConfig.hourStep;
   if ($attrs.hourStep) {
-    $scope.$parent.$watch($parse($attrs.hourStep), function(value) {
+    watchers.push($scope.$parent.$watch($parse($attrs.hourStep), function(value) {
       hourStep = +value;
-    });
+    }));
   }
 
   var minuteStep = timepickerConfig.minuteStep;
   if ($attrs.minuteStep) {
-    $scope.$parent.$watch($parse($attrs.minuteStep), function(value) {
+    watchers.push($scope.$parent.$watch($parse($attrs.minuteStep), function(value) {
       minuteStep = +value;
-    });
+    }));
   }
 
   var min;
-  $scope.$parent.$watch($parse($attrs.min), function(value) {
+  watchers.push($scope.$parent.$watch($parse($attrs.min), function(value) {
     var dt = new Date(value);
     min = isNaN(dt) ? undefined : dt;
-  });
+  }));
 
   var max;
-  $scope.$parent.$watch($parse($attrs.max), function(value) {
+  watchers.push($scope.$parent.$watch($parse($attrs.max), function(value) {
     var dt = new Date(value);
     max = isNaN(dt) ? undefined : dt;
-  });
+  }));
 
   var disabled = false;
   if ($attrs.ngDisabled) {
-    $scope.$parent.$watch($parse($attrs.ngDisabled), function(value) {
+    watchers.push($scope.$parent.$watch($parse($attrs.ngDisabled), function(value) {
       disabled = value;
-    });
+    }));
   }
 
   $scope.noIncrementHours = function() {
@@ -128,22 +129,22 @@ angular.module('ui.bootstrap.timepicker', [])
 
   var secondStep = timepickerConfig.secondStep;
   if ($attrs.secondStep) {
-    $scope.$parent.$watch($parse($attrs.secondStep), function(value) {
+    watchers.push($scope.$parent.$watch($parse($attrs.secondStep), function(value) {
       secondStep = +value;
-    });
+    }));
   }
 
   $scope.showSeconds = timepickerConfig.showSeconds;
   if ($attrs.showSeconds) {
-    $scope.$parent.$watch($parse($attrs.showSeconds), function(value) {
+    watchers.push($scope.$parent.$watch($parse($attrs.showSeconds), function(value) {
       $scope.showSeconds = !!value;
-    });
+    }));
   }
 
   // 12H / 24H mode
   $scope.showMeridian = timepickerConfig.showMeridian;
   if ($attrs.showMeridian) {
-    $scope.$parent.$watch($parse($attrs.showMeridian), function(value) {
+    watchers.push($scope.$parent.$watch($parse($attrs.showMeridian), function(value) {
       $scope.showMeridian = !!value;
 
       if (ngModelCtrl.$error.time) {
@@ -156,7 +157,7 @@ angular.module('ui.bootstrap.timepicker', [])
       } else {
         updateTemplate();
       }
-    });
+    }));
   }
 
   // Get $scope.hours in 24H mode if valid
@@ -518,6 +519,12 @@ angular.module('ui.bootstrap.timepicker', [])
   $scope.blur = function() {
     ngModelCtrl.$setTouched();
   };
+
+  $scope.$on('$destroy', function() {
+    while (watchers.length) {
+      watchers.shift()();
+    }
+  });
 }])
 
 .directive('uibTimepicker', ['uibTimepickerConfig', function(uibTimepickerConfig) {