Merge pull request #20 from davidmorgan/review-comments

Add PrimitiveSerializer and StructuredSerializer interfaces.

Author: davidmorgan

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## 0.0.5
+
+- Add PrimitiveSerializer and StructuredSerializer interfaces.
+
 ## 0.0.4
 
 - Update built_value dependency to 0.0.6.

built_json/lib/built_json.dart

@@ -17,7 +17,7 @@ export 'package:built_collection/built_collection.dart' show BuiltList;
 
 /// Serializes all known classes.
 ///
-/// See <https://github.com/google/built_json.dart/tree/master/example>
+/// See: https://github.com/google/built_json.dart/tree/master/example
 abstract class Serializers {
   /// Default [Serializers] that can serialize primitives and collections.
   ///
@@ -35,7 +35,7 @@ abstract class Serializers {
 
   /// Serializes [object].
   ///
-  /// A [Serializer] must have been provided for every the object uses.
+  /// A [Serializer] must have been provided for every type the object uses.
   ///
   /// Types that are known statically can be provided via [specifiedType]. This
   /// will reduce the amount of data needed on the wire. The exact same
@@ -49,7 +49,7 @@ abstract class Serializers {
 
   /// Deserializes [serialized].
   ///
-  /// A [Serializer] must have been provided for every the object uses.
+  /// A [Serializer] must have been provided for every type the object uses.
   ///
   /// If [serialized] was produced by calling [serialize] with [specifiedType],
   /// the exact same [specifiedType] must be provided to deserialize.
@@ -115,10 +115,10 @@ class FullType {
 /// are provided for collections and primitives in `built_json`. Classes using
 /// `built_value` and enums using `EnumClass` can have implementations
 /// generated using `built_json_generator`.
+///
+/// Implementations must extend either [PrimitiveSerializer] or
+/// [StructuredSerializer].
 abstract class Serializer<T> {
-  /// Whether the serialized format for this type is structured or primitive.
-  bool get structured;
-
   /// The [Type]s that can be serialized.
   ///
   /// They must all be equal to T or a subclass of T. Subclasses are used when
@@ -130,20 +130,54 @@ abstract class Serializer<T> {
   /// For primitives and collections a lower-case name is defined as part of
   /// the `built_json` wire format.
   String get wireName;
+}
 
+/// A [Serializer] that serializes to and from primitive JSON values.
+abstract class PrimitiveSerializer<T> implements Serializer<T> {
   /// Serializes [object].
   ///
   /// Use [serializers] as needed for nested serialization. Information about
   /// the type being serialized is provided in [specifiedType].
   ///
+  /// Returns a value that can be represented as a JSON primitive: a boolean,
+  /// an integer, a double, or a String.
+  ///
   /// TODO(davidmorgan): document the wire format.
   Object serialize(Serializers serializers, T object,
       {FullType specifiedType: FullType.unspecified});
 
   /// Deserializes [serialized].
   ///
+  /// [serialized] is a boolean, an integer, a double or a String.
+  ///
   /// Use [serializers] as needed for nested deserialization. Information about
   /// the type being deserialized is provided in [specifiedType].
   T deserialize(Serializers serializers, Object serialized,
       {FullType specifiedType: FullType.unspecified});
 }
+
+/// A [Serializer] that serializes to and from an [Iterable] of primitive JSON
+/// values.
+abstract class StructuredSerializer<T> implements Serializer<T> {
+  /// Serializes [object].
+  ///
+  /// Use [serializers] as needed for nested serialization. Information about
+  /// the type being serialized is provided in [specifiedType].
+  ///
+  /// Returns an [Iterable] of values that can be represented as structured
+  /// JSON: booleans, integers, doubles, Strings and [Iterable]s.
+  ///
+  /// TODO(davidmorgan): document the wire format.
+  Iterable serialize(Serializers serializers, T object,
+      {FullType specifiedType: FullType.unspecified});
+
+  /// Deserializes [serialized].
+  ///
+  /// [serialized] is an [Iterable] that may contain booleans, integers,
+  /// doubles, Strings and/or [Iterable]s.
+  ///
+  /// Use [serializers] as needed for nested deserialization. Information about
+  /// the type being deserialized is provided in [specifiedType].
+  T deserialize(Serializers serializers, Iterable serialized,
+      {FullType specifiedType: FullType.unspecified});
+}

built_json/lib/src/bool_serializer.dart

@@ -5,7 +5,7 @@
 import 'package:built_collection/built_collection.dart';
 import 'package:built_json/built_json.dart';
 
-class BoolSerializer implements Serializer<bool> {
+class BoolSerializer implements PrimitiveSerializer<bool> {
   final bool structured = false;
   final Iterable<Type> types = new BuiltList<Type>([bool]);
   final String wireName = 'bool';

built_json/lib/src/built_json_serializers.dart

@@ -1,4 +1,5 @@
 // Copyright (c) 2015, 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.
 
@@ -8,8 +9,17 @@ import 'package:built_json/built_json.dart';
 /// Default implementation of [Serializers].
 class BuiltJsonSerializers implements Serializers {
   final BuiltMap<Type, Serializer> _typeToSerializer;
+
+  // Implementation note: wire name is what gets sent in the JSON, type name is
+  // the runtime type name. Type name is complicated for two reasons:
+  //
+  // 1. Built Value classes have two types, the abstract class and the
+  // generated implementation.
+  //
+  // 2. When compiled to javascript the runtime type names are obfuscated.
   final BuiltMap<String, Serializer> _wireNameToSerializer;
   final BuiltMap<String, Serializer> _typeNameToSerializer;
+
   final BuiltMap<FullType, Function> _builderFactories;
 
   BuiltJsonSerializers._(this._typeToSerializer, this._wireNameToSerializer,
@@ -20,23 +30,36 @@ class BuiltJsonSerializers implements Serializers {
       {FullType specifiedType: FullType.unspecified}) {
     if (specifiedType.isUnspecified) {
       final serializer = _getSerializerByType(object.runtimeType);
-      if (serializer == null) throw new StateError(
-          "No serializer for '${object.runtimeType}'.");
-      final serialized = serializer.serialize(this, object);
-
-      if (serializer.structured) {
+      if (serializer == null) {
+        throw new StateError("No serializer for '${object.runtimeType}'.");
+      }
+      if (serializer is StructuredSerializer) {
         final result = <Object>[serializer.wireName];
-        return result..addAll(serialized as Iterable);
+        return result..addAll(serializer.serialize(this, object));
+      } else if (serializer is PrimitiveSerializer) {
+        return <Object>[
+          serializer.wireName,
+          serializer.serialize(this, object)
+        ];
       } else {
-        return <Object>[serializer.wireName, serialized];
+        throw new StateError(
+            'serializer must be StructuredSerializer or PrimitiveSerializer');
       }
     } else {
       final serializer = _getSerializerByType(specifiedType.root);
-      if (serializer == null) throw new StateError(
-          "No serializer for '${specifiedType.root}'.");
-      final result =
-          serializer.serialize(this, object, specifiedType: specifiedType);
-      return serializer.structured ? (result as Iterable).toList() : result;
+      if (serializer == null) {
+        throw new StateError("No serializer for '${specifiedType.root}'.");
+      }
+      if (serializer is StructuredSerializer) {
+        return serializer
+            .serialize(this, object, specifiedType: specifiedType)
+            .toList();
+      } else if (serializer is PrimitiveSerializer) {
+        return serializer.serialize(this, object, specifiedType: specifiedType);
+      } else {
+        throw new StateError(
+            'serializer must be StructuredSerializer or PrimitiveSerializer');
+      }
     }
   }
 
@@ -50,15 +73,29 @@ class BuiltJsonSerializers implements Serializers {
       if (serializer == null) {
         throw new StateError("No serializer for '${wireName}'.");
       }
-      final json = serializer.structured
-          ? (object as List).sublist(1)
-          : (object as List)[1];
-      return serializer.deserialize(this, json);
+
+      if (serializer is StructuredSerializer) {
+        return serializer.deserialize(this, (object as List).sublist(1));
+      } else if (serializer is PrimitiveSerializer) {
+        return serializer.deserialize(this, (object as List)[1]);
+      } else {
+        throw new StateError(
+            'serializer must be StructuredSerializer or PrimitiveSerializer');
+      }
     } else {
       final serializer = _getSerializerByType(specifiedType.root);
-      if (serializer == null) throw new StateError(
-          "No serializer for '${specifiedType.root}'.");
-      return serializer.deserialize(this, object, specifiedType: specifiedType);
+      if (serializer == null) {
+        throw new StateError("No serializer for '${specifiedType.root}'.");
+      }
+
+      if (serializer is StructuredSerializer) {
+        return serializer.deserialize(this, object as Iterable, specifiedType: specifiedType);
+      } else if (serializer is PrimitiveSerializer) {
+        return serializer.deserialize(this, object, specifiedType: specifiedType);
+      } else {
+        throw new StateError(
+            'serializer must be StructuredSerializer or PrimitiveSerializer');
+      }
     }
   }
 
@@ -90,24 +127,29 @@ class BuiltJsonSerializers implements Serializers {
 /// Default implementation of [SerializersBuilder].
 class BuiltJsonSerializersBuilder implements SerializersBuilder {
   MapBuilder<Type, Serializer> _typeToSerializer =
-      new MapBuilder<Type, Serializer>();
+  new MapBuilder<Type, Serializer>();
   MapBuilder<String, Serializer> _wireNameToSerializer =
-      new MapBuilder<String, Serializer>();
+  new MapBuilder<String, Serializer>();
   MapBuilder<String, Serializer> _typeNameToSerializer =
-      new MapBuilder<String, Serializer>();
+  new MapBuilder<String, Serializer>();
 
   MapBuilder<FullType, Function> _builderFactories =
-      new MapBuilder<FullType, Function>();
+  new MapBuilder<FullType, Function>();
 
   BuiltJsonSerializersBuilder();
 
-  BuiltJsonSerializersBuilder._(
-      this._typeToSerializer,
+  BuiltJsonSerializersBuilder._(this._typeToSerializer,
       this._wireNameToSerializer,
       this._typeNameToSerializer,
       this._builderFactories);
 
   void add(Serializer serializer) {
+    if (serializer is! StructuredSerializer &&
+        serializer is! PrimitiveSerializer) {
+      throw new ArgumentError(
+          'serializer must be StructuredSerializer or PrimitiveSerializer');
+    }
+
     _wireNameToSerializer[serializer.wireName] = serializer;
     for (final type in serializer.types) {
       _typeToSerializer[type] = serializer;

built_json/lib/src/built_list_serializer.dart

@@ -5,13 +5,13 @@
 import 'package:built_collection/built_collection.dart';
 import 'package:built_json/built_json.dart';
 
-class BuiltListSerializer implements Serializer<BuiltList> {
+class BuiltListSerializer implements StructuredSerializer<BuiltList> {
   final bool structured = true;
   final Iterable<Type> types = new BuiltList<Type>([BuiltList]);
   final String wireName = 'list';
 
   @override
-  Object serialize(Serializers serializers, BuiltList builtList,
+  Iterable serialize(Serializers serializers, BuiltList builtList,
       {FullType specifiedType: FullType.unspecified}) {
     final isUnderspecified =
         specifiedType.isUnspecified || specifiedType.parameters.isEmpty;
@@ -30,7 +30,7 @@ class BuiltListSerializer implements Serializer<BuiltList> {
   }
 
   @override
-  BuiltList deserialize(Serializers serializers, Object serialized,
+  BuiltList deserialize(Serializers serializers, Iterable serialized,
       {FullType specifiedType: FullType.unspecified}) {
     final isUnderspecified =
         specifiedType.isUnspecified || specifiedType.parameters.isEmpty;
@@ -39,14 +39,14 @@ class BuiltListSerializer implements Serializer<BuiltList> {
         ? FullType.unspecified
         : specifiedType.parameters[0];
 
-    final result = isUnderspecified
+    ListBuilder result = isUnderspecified
         ? new ListBuilder<Object>()
         : serializers.newBuilder(specifiedType) as ListBuilder;
     if (result == null) {
       throw new StateError(
           'No builder for $specifiedType, cannot deserialize.');
     }
-    result.addAll((serialized as Iterable).map((item) =>
+    result.addAll(serialized.map((item) =>
         serializers.deserialize(item, specifiedType: elementType)));
     return result.build();
   }

built_json/lib/src/built_map_serializer.dart

@@ -5,13 +5,13 @@
 import 'package:built_collection/built_collection.dart';
 import 'package:built_json/built_json.dart';
 
-class BuiltMapSerializer implements Serializer<BuiltMap> {
+class BuiltMapSerializer implements StructuredSerializer<BuiltMap> {
   final bool structured = true;
   final Iterable<Type> types = new BuiltList<Type>([BuiltMap]);
   final String wireName = 'map';
 
   @override
-  Object serialize(Serializers serializers, BuiltMap builtMap,
+  Iterable serialize(Serializers serializers, BuiltMap builtMap,
       {FullType specifiedType: FullType.unspecified}) {
     final isUnderspecified =
         specifiedType.isUnspecified || specifiedType.parameters.isEmpty;
@@ -37,7 +37,7 @@ class BuiltMapSerializer implements Serializer<BuiltMap> {
   }
 
   @override
-  BuiltMap deserialize(Serializers serializers, Object serialized,
+  BuiltMap deserialize(Serializers serializers, Iterable serialized,
       {FullType specifiedType: FullType.unspecified}) {
     final isUnderspecified =
         specifiedType.isUnspecified || specifiedType.parameters.isEmpty;
@@ -49,23 +49,23 @@ class BuiltMapSerializer implements Serializer<BuiltMap> {
         ? FullType.unspecified
         : specifiedType.parameters[1];
 
-    final result = isUnderspecified
+    MapBuilder result = isUnderspecified
         ? new MapBuilder<Object, Object>()
         : serializers.newBuilder(specifiedType) as MapBuilder;
     if (result == null) {
       throw new StateError(
           'No builder for $specifiedType, cannot deserialize.');
     }
-    final list = serialized as List<Object>;
 
-    if (list.length & 1 == 1) {
+    if (serialized.length % 2 == 1) {
       throw new ArgumentError('odd length');
     }
 
-    for (int i = 0; i != list.length; i += 2) {
-      final key = serializers.deserialize(list[i], specifiedType: keyType);
-      final value =
-          serializers.deserialize(list[i + 1], specifiedType: valueType);
+    for (int i = 0; i != serialized.length; i += 2) {
+      final key = serializers.deserialize(serialized.elementAt(i),
+          specifiedType: keyType);
+      final value = serializers.deserialize(serialized.elementAt(i + 1),
+          specifiedType: valueType);
       result[key] = value;
     }