Add JsonObject class and serializer.

Author: davidmorgan

CHANGELOG.md

@@ -3,6 +3,9 @@
 ## 0.5.6
 
 - Add serializer for "DateTime" fields.
+- Add JsonObject class and serializer.
+- Add convenience methods Seralizers.serializeWith and deserializeWith. 
+- Add example for using StandardJsonPlugin.
 
 ## 0.5.5
 

built_value/lib/json_object.dart

@@ -0,0 +1,202 @@
+// Copyright (c) 2017, 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:collection/collection.dart';
+
+/// A JSON value.
+///
+/// This class is suitable for use in built_value fields. When serialized it
+/// maps directly onto JSON values.
+///
+/// Deep operator== and hashCode are provided, meaning the contents of a
+/// List or Map is used for equality and hashing.
+///
+/// List and Map classes are wrapped in [UnmodifiableListView] and
+/// [UnmodifiableMapView] so they won't be modifiable via this object. You
+/// must ensure that no updates are made via the original reference, as a
+/// copy is not made.
+abstract class JsonObject {
+  /// The value, which may be a bool, a List, a Map, a num or a String.
+  Object get value;
+
+  /// Whether the value is a [bool].
+  bool get isBool => false;
+
+  /// The value as a [bool], or throw if not.
+  bool get asBool => throw new StateError('Not a bool.');
+
+  /// Whether the value is a [List].
+  bool get isList => false;
+
+  /// The value as a [List], or throw if not.
+  List get asList => throw new StateError('Not a List.');
+
+  /// Whether the value is a [Map].
+  bool get isMap => false;
+
+  /// The value as a [Map], or throw if not.
+  Map get asMap => throw new StateError('Not a Map.');
+
+  /// Whether the value is a [num].
+  bool get isNum => false;
+
+  /// The value as a [num], or throw if not.
+  num get asNum => throw new StateError('Not a num.');
+
+  /// Whether the value is a [String].
+  bool get isString => false;
+
+  /// The value as a [String], or throw if not.
+  String get asString => throw new StateError('Not a String.');
+
+  /// Instantiates with [value], which must be a bool, a List, a Map, a num
+  /// or a String. Otherwise, an [ArgumentError] is thrown.
+  factory JsonObject(Object value) {
+    if (value is num) {
+      return new NumJsonObject(value);
+    } else if (value is String) {
+      return new StringJsonObject(value);
+    } else if (value is bool) {
+      return new BoolJsonObject(value);
+    } else if (value is List<Object>) {
+      return new ListJsonObject(value);
+    } else if (value is Map<String, Object>) {
+      return new MapJsonObject(value);
+    } else {
+      throw new ArgumentError.value(value, 'value',
+          'Must be bool, List<Object>, Map<String, Object>, num or String.');
+    }
+  }
+
+  JsonObject._();
+
+  @override
+  String toString() {
+    return value.toString();
+  }
+}
+
+/// A [JsonObject] holding a bool.
+class BoolJsonObject extends JsonObject {
+  @override
+  final bool value;
+
+  BoolJsonObject(this.value) : super._();
+
+  @override
+  bool get isBool => true;
+
+  @override
+  bool get asBool => value;
+
+  @override
+  bool operator ==(dynamic other) {
+    if (identical(other, this)) return true;
+    if (other is! BoolJsonObject) return false;
+    return value == other.value;
+  }
+
+  @override
+  int get hashCode => value.hashCode;
+}
+
+/// A [JsonObject] holding a List.
+class ListJsonObject extends JsonObject {
+  @override
+  final List<Object> value;
+
+  ListJsonObject(List<Object> value)
+      : this.value = new UnmodifiableListView<Object>(value),
+        super._();
+
+  @override
+  bool get isList => true;
+
+  @override
+  List<Object> get asList => value;
+
+  @override
+  bool operator ==(dynamic other) {
+    if (identical(other, this)) return true;
+    if (other is! ListJsonObject) return false;
+    return const DeepCollectionEquality().equals(value, other.value);
+  }
+
+  @override
+  int get hashCode => const DeepCollectionEquality().hash(value);
+}
+
+/// A [JsonObject] holding a Map.
+class MapJsonObject extends JsonObject {
+  @override
+  final Map<String, Object> value;
+
+  MapJsonObject(Map<String, Object> value)
+      : this.value = new UnmodifiableMapView(value),
+        super._();
+
+  @override
+  bool get isMap => true;
+
+  @override
+  Map<String, Object> get asMap => value;
+
+  @override
+  bool operator ==(dynamic other) {
+    if (identical(other, this)) return true;
+    if (other is! MapJsonObject) return false;
+    return const DeepCollectionEquality().equals(value, other.value);
+  }
+
+  @override
+  int get hashCode => const DeepCollectionEquality().hash(value);
+}
+
+/// A [JsonObject] holding a num.
+class NumJsonObject extends JsonObject {
+  @override
+  final num value;
+
+  NumJsonObject(this.value) : super._();
+
+  @override
+  bool get isNum => true;
+
+  @override
+  num get asNum => value;
+
+  @override
+  bool operator ==(dynamic other) {
+    if (identical(other, this)) return true;
+    if (other is! NumJsonObject) return false;
+    return value == other.value;
+  }
+
+  @override
+  int get hashCode => value.hashCode;
+}
+
+/// A [JsonObject] holding a String.
+class StringJsonObject extends JsonObject {
+  @override
+  final String value;
+
+  StringJsonObject(this.value) : super._();
+
+  @override
+  bool get isString => true;
+
+  @override
+  String get asString => value;
+
+  @override
+  bool operator ==(dynamic other) {
+    if (identical(other, this)) return true;
+    if (other is! StringJsonObject) return false;
+    return value == other.value;
+  }
+
+  @override
+  int get hashCode => value.hashCode;
+}

built_value/lib/serializer.dart

@@ -4,6 +4,7 @@
 
 import 'package:built_collection/built_collection.dart';
 import 'package:built_value/src/date_time_serializer.dart';
+import 'package:built_value/src/json_object_serializer.dart';
 import 'package:built_value/src/num_serializer.dart';
 import 'package:quiver/core.dart';
 
@@ -36,6 +37,7 @@ abstract class Serializers {
           ..add(new DateTimeSerializer())
           ..add(new DoubleSerializer())
           ..add(new IntSerializer())
+          ..add(new JsonObjectSerializer())
           ..add(new NumSerializer())
           ..add(new StringSerializer())
           ..addBuilderFactory(
@@ -72,6 +74,11 @@ abstract class Serializers {
   Object serialize(Object object,
       {FullType specifiedType: FullType.unspecified});
 
+  /// Convenience method for when you know the type you're serializing.
+  /// Specify the type by specifying its [Serializer] class. Equivalent to
+  /// calling [serialize] with a `specifiedType`.
+  Object serializeWith<T>(Serializer<T> serializer, T object);
+
   /// Deserializes [serialized].
   ///
   /// A [Serializer] must have been provided for every type the object uses.
@@ -81,6 +88,11 @@ abstract class Serializers {
   Object deserialize(Object serialized,
       {FullType specifiedType: FullType.unspecified});
 
+  /// Convenience method for when you know the type you're deserializing.
+  /// Specify the type by specifying its [Serializer] class. Equivalent to
+  /// calling [deserialize] with a `specifiedType`.
+  T deserializeWith<T>(Serializer<T> serializer, Object serialized);
+
   /// Creates a new builder for the type represented by [fullType].
   ///
   /// For example, if [fullType] is `BuiltList<int, String>`, returns a

built_value/lib/src/built_json_serializers.dart

@@ -5,6 +5,7 @@
 
 import 'package:built_collection/built_collection.dart';
 import 'package:built_value/serializer.dart';
+import 'package:built_value/serializer.dart';
 
 /// Default implementation of [Serializers].
 class BuiltJsonSerializers implements Serializers {
@@ -27,6 +28,18 @@ class BuiltJsonSerializers implements Serializers {
   BuiltJsonSerializers._(this._typeToSerializer, this._wireNameToSerializer,
       this._typeNameToSerializer, this._builderFactories, this._plugins);
 
+  @override
+  T deserializeWith<T>(Serializer<T> serializer, Object serialized) {
+    return deserialize(serialized,
+        specifiedType: new FullType(serializer.types.first)) as T;
+  }
+
+  @override
+  Object serializeWith<T>(Serializer<T> serializer, T object) {
+    return serialize(object,
+        specifiedType: new FullType(serializer.types.first));
+  }
+
   @override
   Object serialize(Object object,
       {FullType specifiedType: FullType.unspecified}) {

built_value/lib/src/json_object_serializer.dart

@@ -0,0 +1,34 @@
+// Copyright (c) 2017, 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/json_object.dart';
+import 'package:built_value/serializer.dart';
+
+class JsonObjectSerializer implements PrimitiveSerializer<JsonObject> {
+  final bool structured = false;
+  @override
+  final Iterable<Type> types = new BuiltList<Type>([
+    JsonObject,
+    BoolJsonObject,
+    ListJsonObject,
+    MapJsonObject,
+    NumJsonObject,
+    StringJsonObject,
+  ]);
+  @override
+  final String wireName = 'JsonObject';
+
+  @override
+  Object serialize(Serializers serializers, JsonObject jsonObject,
+      {FullType specifiedType: FullType.unspecified}) {
+    return jsonObject.value;
+  }
+
+  @override
+  JsonObject deserialize(Serializers serializers, Object serialized,
+      {FullType specifiedType: FullType.unspecified}) {
+    return new JsonObject(serialized);
+  }
+}

built_value/lib/standard_json_plugin.dart

@@ -1,4 +1,5 @@
 import 'package:built_collection/built_collection.dart';
+import 'package:built_value/json_object.dart';
 import 'package:built_value/serializer.dart';
 import 'dart:convert' show JSON;
 
@@ -25,14 +26,16 @@ class StandardJsonPlugin implements SerializerPlugin {
 
   @override
   Object afterSerialize(Object object, FullType specifiedType) {
-    return object is List && specifiedType.root != BuiltList
+    return object is List &&
+            specifiedType.root != BuiltList &&
+            specifiedType.root != JsonObject
         ? _toMap(object, _alreadyHasStringKeys(specifiedType))
         : object;
   }
 
   @override
   Object beforeDeserialize(Object object, FullType specifiedType) {
-    return object is Map
+    return object is Map && specifiedType.root != JsonObject
         ? _toList(object, _alreadyHasStringKeys(specifiedType))
         : object;
   }