Merge pull request #429 from davidmorgan/iso-datetime

Add Iso8601DateTimeSerializer.

CHANGELOG.md

@@ -4,8 +4,11 @@
 
 - Support serializing `BuiltSet` with `StandardJsonPlugin`. It's serialized to
   a JSON list.
+- Add `Iso8601DateTimeSerializer` for use when you want ISO8601 serialization
+  instead of microseconds since epoch.
 - Fix code generation when inherited generic fields are made non-generic. 
 
+
 # 5.4.5
 
 - Improve error message on failure to deserialize.

built_value/lib/iso_8601_date_time_serializer.dart

@@ -0,0 +1,38 @@
+// Copyright (c) 2018, Google Inc. Please see the AUTHORS file for details.
+// All rights reserved. Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+import 'package:built_collection/built_collection.dart';
+import 'package:built_value/serializer.dart';
+
+/// Alternative serializer for [DateTime].
+///
+/// Install this to use ISO8601 format instead of the default (microseconds
+/// since epoch). Use [SerializersBuilder.add] to install it.
+///
+/// An exception will be thrown on attempt to serialize local DateTime
+/// instances; you must use UTC.
+class Iso8601DateTimeSerializer implements PrimitiveSerializer<DateTime> {
+  final bool structured = false;
+  @override
+  final Iterable<Type> types = new BuiltList<Type>([DateTime]);
+  @override
+  final String wireName = 'DateTime';
+
+  @override
+  Object serialize(Serializers serializers, DateTime dateTime,
+      {FullType specifiedType: FullType.unspecified}) {
+    if (!dateTime.isUtc) {
+      throw new ArgumentError.value(
+          dateTime, 'dateTime', 'Must be in utc for serialization.');
+    }
+
+    return dateTime.toIso8601String();
+  }
+
+  @override
+  DateTime deserialize(Serializers serializers, Object serialized,
+      {FullType specifiedType: FullType.unspecified}) {
+    return DateTime.parse(serialized as String).toUtc();
+  }
+}

built_value/lib/standard_json_plugin.dart

@@ -9,6 +9,10 @@ import 'dart:convert' show json;
 /// and support for more collection types. But, you may need to interact with
 /// other systems that use simple map-based JSON. If so, use
 /// [SerializersBuilder.addPlugin] to install this plugin.
+///
+/// When using this plugin you may wish to also install
+/// `Iso8601DateTimeSerializer` which switches serialization of `DateTime`
+/// from microseconds since epoch to ISO 8601 format.
 class StandardJsonPlugin implements SerializerPlugin {
   static final BuiltSet<Type> _unsupportedTypes =
       new BuiltSet<Type>([BuiltListMultimap, BuiltSetMultimap]);

built_value/test/iso_8601_date_time_serializer_test.dart

@@ -0,0 +1,50 @@
+// Copyright (c) 2018, Google Inc. Please see the AUTHORS file for details.
+// All rights reserved. Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+import 'package:built_value/iso_8601_date_time_serializer.dart';
+import 'package:built_value/serializer.dart';
+import 'package:test/test.dart';
+
+void main() {
+  final serializers = (new Serializers().toBuilder()
+        ..add(new Iso8601DateTimeSerializer()))
+      .build();
+
+  group('DateTime with known specifiedType', () {
+    final data = new DateTime.utc(1980, 1, 2, 3, 4, 5, 6, 7);
+    final serialized = '1980-01-02T03:04:05.006007Z';
+    final specifiedType = const FullType(DateTime);
+
+    test('can be serialized', () {
+      expect(serializers.serialize(data, specifiedType: specifiedType),
+          serialized);
+    });
+
+    test('can be deserialized', () {
+      expect(serializers.deserialize(serialized, specifiedType: specifiedType),
+          data);
+    });
+
+    test('serialize throws if not UTC', () {
+      expect(() => serializers.serialize(new DateTime.now()),
+          throwsA(new isInstanceOf<ArgumentError>()));
+    });
+  });
+
+  group('DateTime with unknown specifiedType', () {
+    final data = new DateTime.utc(1980, 1, 2, 3, 4, 5, 6, 7);
+    final serialized = ['DateTime', '1980-01-02T03:04:05.006007Z'];
+    final specifiedType = FullType.unspecified;
+
+    test('can be serialized', () {
+      expect(serializers.serialize(data, specifiedType: specifiedType),
+          serialized);
+    });
+
+    test('can be deserialized', () {
+      expect(serializers.deserialize(serialized, specifiedType: specifiedType),
+          data);
+    });
+  });
+}