refactor(filters/ngModel): extract common methods

Closes #11005

Author: shahata

src/.jshintrc

@@ -71,6 +71,8 @@
     "toJsonReplacer": false,
     "toJson": false,
     "fromJson": false,
+    "convertTimezoneToLocal": false,
+    "timezoneToOffset": false,
     "startingTag": false,
     "tryDecodeURIComponent": false,
     "parseKeyValue": false,

src/Angular.js

@@ -66,6 +66,8 @@
   toJsonReplacer: true,
   toJson: true,
   fromJson: true,
+  convertTimezoneToLocal: true,
+  timezoneToOffset: true,
   startingTag: true,
   tryDecodeURIComponent: true,
   parseKeyValue: true,
@@ -1109,6 +1111,26 @@ function fromJson(json) {
 }
 
 
+function timezoneToOffset(timezone, fallback) {
+  var requestedTimezoneOffset = Date.parse('Jan 01, 1970 00:00:00 ' + timezone) / 60000;
+  return isNaN(requestedTimezoneOffset) ? fallback : requestedTimezoneOffset;
+}
+
+
+function addDateMinutes(date, minutes) {
+  date = new Date(date.getTime());
+  date.setMinutes(date.getMinutes() + minutes);
+  return date;
+}
+
+
+function convertTimezoneToLocal(date, timezone, reverse) {
+  reverse = reverse ? -1 : 1;
+  var timezoneOffset = timezoneToOffset(timezone, date.getTimezoneOffset());
+  return addDateMinutes(date, reverse * (timezoneOffset - date.getTimezoneOffset()));
+}
+
+
 /**
  * @returns {string} Returns the string representation of the element.
  */

src/ng/directive/input.js

@@ -1157,11 +1157,7 @@ function createDateInputType(type, regexp, parseDate, format) {
         // contains some different data format!
         var parsedDate = parseDate(value, previousDate);
         if (timezone) {
-          var requestedTimezoneOffset = Date.parse('Jan 01, 1970 00:00:00 ' + timezone) / 60000;
-          if (!isNaN(requestedTimezoneOffset)) {
-            parsedDate = new Date(parsedDate.getTime());
-            parsedDate.setMinutes(parsedDate.getMinutes() - parsedDate.getTimezoneOffset() + requestedTimezoneOffset);
-          }
+          parsedDate = convertTimezoneToLocal(parsedDate, timezone);
         }
         return parsedDate;
       }
@@ -1175,11 +1171,7 @@ function createDateInputType(type, regexp, parseDate, format) {
       if (isValidDate(value)) {
         previousDate = value;
         if (previousDate && timezone) {
-          var requestedTimezoneOffset = Date.parse('Jan 01, 1970 00:00:00 ' + timezone) / 60000;
-          if (!isNaN(requestedTimezoneOffset)) {
-            previousDate = new Date(previousDate.getTime());
-            previousDate.setMinutes(previousDate.getMinutes() + previousDate.getTimezoneOffset() - requestedTimezoneOffset);
-          }
+          previousDate = convertTimezoneToLocal(previousDate, timezone, true);
         }
         return $filter('date')(value, format, timezone);
       } else {

src/ng/filter/filters.js

@@ -488,12 +488,8 @@ function dateFilter($locale) {
 
     var dateTimezoneOffset = date.getTimezoneOffset();
     if (timezone) {
-      var requestedTimezoneOffset = Date.parse('Jan 01, 1970 00:00:00 ' + timezone) / 60000;
-      if (!isNaN(requestedTimezoneOffset)) {
-        date = new Date(date.getTime());
-        date.setMinutes(date.getMinutes() + dateTimezoneOffset - requestedTimezoneOffset);
-        dateTimezoneOffset = requestedTimezoneOffset;
-      }
+      dateTimezoneOffset = timezoneToOffset(timezone, date.getTimezoneOffset());
+      date = convertTimezoneToLocal(date, timezone, true);
     }
     forEach(parts, function(value) {
       fn = DATE_FORMATS[value];

test/ng/filter/filtersSpec.js

@@ -464,8 +464,8 @@ describe('filters', function() {
     });
 
     it('should fallback to default timezone in case an unknown timezone was passed', function() {
-      var value = new angular.mock.TzDate(-2, '2003-09-10T01:02:04.000Z');
-      expect(date(value, 'yyyy-MM-dd HH-mm-ssZ', 'WTF')).toEqual('2003-09-10 03-02-04+0200');
+      var value = new Date(2003, 8, 10, 3, 2, 4);
+      expect(date(value, 'yyyy-MM-dd HH-mm-ssZ', 'WTF')).toEqual(date(value, 'yyyy-MM-dd HH-mm-ssZ'));
     });
   });
 });