Merge pull request #891 from wger-project/fix/timezone-problems

Better handling of time zones

Author: rolandgeider

lib/helpers/date.dart

@@ -0,0 +1,40 @@
+/*
+ * This file is part of wger Workout Manager <https://github.com/wger-project>.
+ * Copyright (C) wger Team
+ *
+ * wger Workout Manager is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * wger Workout Manager is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/// Returns a timezone aware DateTime object from a date and time string.
+DateTime getDateTimeFromDateAndTime(String date, String time) {
+  return DateTime.parse('$date $time');
+}
+
+/// Returns a list of [DateTime] objects from [first] to [last], inclusive.
+List<DateTime> daysInRange(DateTime first, DateTime last) {
+  final dayCount = last.difference(first).inDays + 1;
+  return List.generate(
+    dayCount,
+    (index) => DateTime.utc(first.year, first.month, first.day + index),
+  );
+}
+
+extension DateTimeExtension on DateTime {
+  bool isSameDayAs(DateTime other) {
+    final thisDay = DateTime(year, month, day);
+    final otherDay = DateTime(other.year, other.month, other.day);
+
+    return thisDay.isAtSameMomentAs(otherDay);
+  }
+}

lib/helpers/json.dart

@@ -53,6 +53,15 @@ String? dateToYYYYMMDD(DateTime? dateTime) {
   return DateFormat('yyyy-MM-dd').format(dateTime);
 }
 
+/// Convert a date to UTC and then to an ISO8601 string.
+///
+/// This makes sure that the serialized data has correct timezone information.
+/// Otherwise the django backend will possibly treat the date as local time,
+/// which will not be correct in most cases.
+String dateToUtcIso8601(DateTime dateTime) {
+  return dateTime.toUtc().toIso8601String();
+}
+
 /*
  * Converts a time to a date object.
  * Needed e.g. when the wger api only sends a time but no date information.

lib/helpers/misc.dart

@@ -63,38 +63,6 @@ String repText(
   return out.join(' ');
 }
 
-/// Returns a list of [DateTime] objects from [first] to [last], inclusive.
-List<DateTime> daysInRange(DateTime first, DateTime last) {
-  final dayCount = last.difference(first).inDays + 1;
-  return List.generate(
-    dayCount,
-    (index) => DateTime.utc(first.year, first.month, first.day + index),
-  );
-}
-
-extension TimeOfDayExtension on TimeOfDay {
-  bool isAfter(TimeOfDay other) {
-    return toMinutes() > other.toMinutes();
-  }
-
-  bool isBefore(TimeOfDay other) {
-    return toMinutes() < other.toMinutes();
-  }
-
-  int toMinutes() {
-    return (hour * 60) + minute;
-  }
-}
-
-extension DateTimeExtension on DateTime {
-  bool isSameDayAs(DateTime other) {
-    final thisDay = DateTime(year, month, day);
-    final otherDay = DateTime(other.year, other.month, other.day);
-
-    return thisDay.isAtSameMomentAs(otherDay);
-  }
-}
-
 void launchURL(String url, BuildContext context) async {
   final scaffoldMessenger = ScaffoldMessenger.of(context);
   final launched = await launchUrl(Uri.parse(url));

lib/models/nutrition/log.dart

@@ -36,7 +36,7 @@ class Log {
   @JsonKey(required: true, name: 'plan')
   int planId;
 
-  @JsonKey(required: true)
+  @JsonKey(required: true, toJson: dateToUtcIso8601)
   late DateTime datetime;
 
   String? comment;

lib/models/nutrition/log.g.dart

@@ -19,8 +19,8 @@
 import 'package:flutter/material.dart';
 import 'package:json_annotation/json_annotation.dart';
 import 'package:wger/helpers/consts.dart';
+import 'package:wger/helpers/date.dart';
 import 'package:wger/helpers/json.dart';
-import 'package:wger/helpers/misc.dart';
 import 'package:wger/models/nutrition/log.dart';
 import 'package:wger/models/nutrition/meal_item.dart';
 import 'package:wger/models/nutrition/nutritional_values.dart';

lib/models/nutrition/meal.dart

@@ -38,7 +38,7 @@ class NutritionalPlan {
   @JsonKey(required: true)
   late String description;
 
-  @JsonKey(required: true, name: 'creation_date', toJson: dateToYYYYMMDD)
+  @JsonKey(required: true, name: 'creation_date', toJson: dateToUtcIso8601)
   late DateTime creationDate;
 
   @JsonKey(required: true, name: 'only_logging')

lib/models/nutrition/nutritional_plan.dart

@@ -80,7 +80,7 @@ class Log {
   @JsonKey(includeFromJson: false, includeToJson: false)
   late WeightUnit? weightUnitObj;
 
-  @JsonKey(required: true, toJson: dateToYYYYMMDD)
+  @JsonKey(required: true, toJson: dateToUtcIso8601)
   late DateTime date;
 
   Log({