Default values

README.md

@@ -67,6 +67,7 @@ part 'book.g.dart';
 abstract class _Book extends Model {
   String get author;
 
+  @DefaultValue('[Untitled]')
   String get title;
 
   String get description;

angel_serialize_generator/build.yaml

@@ -27,6 +27,7 @@ targets:
   _book:
     sources:
       - "test/models/book.dart"
+      - "test/models/goat.dart"
       - "test/models/game_pad_button.dart"
       - "test/models/with_enum.dart"
   _typescript_definition:

angel_serialize_generator/lib/angel_serialize_generator.dart

@@ -2,7 +2,7 @@ library angel_serialize_generator;
 
 import 'dart:async';
 import 'dart:typed_data';
-
+import 'package:analyzer/dart/constant/value.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:angel_model/angel_model.dart';
@@ -48,6 +48,32 @@ TypeReference convertTypeReference(DartType t) {
   });
 }
 
+String dartObjectToString(DartObject v) {
+  if (v.isNull) return 'null';
+  if (v.toBoolValue() != null) return v.toBoolValue().toString();
+  if (v.toIntValue() != null) return v.toIntValue().toString();
+  if (v.toDoubleValue() != null) return v.toDoubleValue().toString();
+  if (v.toSymbolValue() != null) return '#' + v.toSymbolValue();
+  if (v.toTypeValue() != null) return v.toTypeValue().name;
+  if (v.toListValue() != null)
+    return 'const [' + v.toListValue().map(dartObjectToString).join(', ') + ']';
+  if (v.toMapValue() != null) {
+    return 'const {' +
+        v.toMapValue().entries.map((entry) {
+          var k = dartObjectToString(entry.key);
+          var v = dartObjectToString(entry.value);
+          return '$k: $v';
+        }).join(', ') +
+        '}';
+  }
+  if (v.toStringValue() != null) {
+    return literalString(v.toStringValue())
+        .accept(new DartEmitter())
+        .toString();
+  }
+  throw new ArgumentError(v.toString());
+}
+
 /// Determines if a type supports `package:angel_serialize`.
 bool isModelClass(DartType t) {
   if (t == null) return false;

angel_serialize_generator/lib/build_context.dart

@@ -67,6 +67,14 @@ Future<BuildContext> buildContext(
         );
       }
 
+      // Check for @DefaultValue()
+      var defAnn =
+          const TypeChecker.fromRuntime(DefaultValue).firstAnnotationOf(el);
+      if (defAnn != null) {
+        var rev = new ConstantReader(defAnn).revive().positionalArguments[0];
+        ctx.defaults[field.name] = rev;
+      }
+
       // Check for alias
       Alias alias;
       var aliasAnn = aliasTypeChecker.firstAnnotationOf(el);

angel_serialize_generator/lib/context.dart

@@ -1,3 +1,4 @@
+import 'package:analyzer/dart/constant/value.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:angel_serialize/angel_serialize.dart';
 import 'package:code_builder/code_builder.dart';
@@ -15,6 +16,9 @@ class BuildContext {
   /// A map of field names to resolved names from `@Alias()` declarations.
   final Map<String, String> aliases = {};
 
+  /// A map of field names to their default values.
+  final Map<String, DartObject> defaults = {};
+
   /// A map of fields that have been marked as to be excluded from serialization.
   final Map<String, Exclude> excluded = {};
 

angel_serialize_generator/lib/model.dart

@@ -96,6 +96,12 @@ class JsonModelGenerator extends GeneratorForAnnotation<Serializable> {
               ? 'List'
               : 'Map';
           var defaultValue = typeName == 'List' ? '[]' : '{}';
+          var existingDefault = ctx.defaults[field.name];
+
+          if (existingDefault != null) {
+            defaultValue = dartObjectToString(existingDefault);
+          }
+
           constructor.initializers.add(new Code('''
               this.${field.name} =
                 new $typeName.unmodifiable(${field.name} ?? $defaultValue)'''));
@@ -109,6 +115,12 @@ class JsonModelGenerator extends GeneratorForAnnotation<Serializable> {
             ..name = field.name
             ..named = true;
 
+          var existingDefault = ctx.defaults[field.name];
+
+          if (existingDefault != null) {
+            b.defaultTo = new Code(dartObjectToString(existingDefault));
+          }
+
           if (!isListOrMapType(field.type))
             b.toThis = true;
           else {

angel_serialize_generator/lib/serialize.dart

@@ -203,18 +203,27 @@ class SerializerGenerator extends GeneratorForAnnotation<Serializable> {
         String deserializedRepresentation =
             "map['$alias'] as ${typeToString(field.type)}";
 
+        var defaultValue = 'null';
+        var existingDefault = ctx.defaults[field.name];
+
+        if (existingDefault != null) {
+          defaultValue = dartObjectToString(existingDefault);
+          deserializedRepresentation =
+              '$deserializedRepresentation ?? $defaultValue';
+        }
+
         // Deserialize dates
         if (dateTimeTypeChecker.isAssignableFromType(field.type))
           deserializedRepresentation = "map['$alias'] != null ? "
               "(map['$alias'] is DateTime ? (map['$alias'] as DateTime) : DateTime.parse(map['$alias'].toString()))"
-              " : null";
+              " : $defaultValue";
 
         // Serialize model classes via `XSerializer.toMap`
         else if (isModelClass(field.type)) {
           var rc = new ReCase(field.type.name);
           deserializedRepresentation = "map['$alias'] != null"
               " ? ${rc.pascalCase}Serializer.fromMap(map['$alias'] as Map)"
-              " : null";
+              " : $defaultValue";
         } else if (field.type is InterfaceType) {
           var t = field.type as InterfaceType;
 
@@ -224,7 +233,7 @@ class SerializerGenerator extends GeneratorForAnnotation<Serializable> {
                 " ? new List.unmodifiable(((map['$alias'] as Iterable)"
                 ".where((x) => x is Map)  as Iterable<Map>)"
                 ".map(${rc.pascalCase}Serializer.fromMap))"
-                " : null";
+                " : $defaultValue";
           } else if (isMapToModelType(t)) {
             var rc = new ReCase(t.typeArguments[1].name);
             deserializedRepresentation = '''
@@ -233,7 +242,7 @@ class SerializerGenerator extends GeneratorForAnnotation<Serializable> {
                        return out..[key] = ${rc.pascalCase}Serializer
                         .fromMap(((map['$alias'] as Map)[key]) as Map);
                     }))
-                  : null
+                  : $defaultValue
             ''';
           } else if (t.element.isEnum) {
             deserializedRepresentation = '''
@@ -243,7 +252,7 @@ class SerializerGenerator extends GeneratorForAnnotation<Serializable> {
               (
                 map['$alias'] is int
                 ? ${t.name}.values[map['$alias'] as int]
-                : null
+                : $defaultValue
               )
             ''';
           } else if (const TypeChecker.fromRuntime(List)
@@ -254,7 +263,7 @@ class SerializerGenerator extends GeneratorForAnnotation<Serializable> {
             deserializedRepresentation = '''
                 map['$alias'] is Iterable
                   ? (map['$alias'] as Iterable).cast<$arg>().toList()
-                  : null
+                  : $defaultValue
                 ''';
           } else if (const TypeChecker.fromRuntime(Map)
                   .isAssignableFromType(t) &&
@@ -266,7 +275,7 @@ class SerializerGenerator extends GeneratorForAnnotation<Serializable> {
             deserializedRepresentation = '''
                 map['$alias'] is Map
                   ? (map['$alias'] as Map).cast<$key, $value>()
-                  : null
+                  : $defaultValue
                 ''';
           } else if (const TypeChecker.fromRuntime(Uint8List)
               .isAssignableFromType(t)) {
@@ -281,7 +290,7 @@ class SerializerGenerator extends GeneratorForAnnotation<Serializable> {
                   (
                     map['$alias'] is String
                       ? new Uint8List.fromList(base64.decode(map['$alias'] as String))
-                      : null
+                      : $defaultValue
                   )
               )
             ''';

angel_serialize_generator/test/default_value_test.dart

@@ -0,0 +1,24 @@
+import 'package:test/test.dart';
+import 'models/goat.dart';
+
+void main() {
+  group('constructor', () {
+    test('int default', () {
+      expect(Goat().integer, 34);
+    });
+
+    test('list default', () {
+      expect(Goat().list, [34, 35]);
+    });
+  });
+
+  group('from map', () {
+    test('int default', () {
+      expect(GoatSerializer.fromMap({}).integer, 34);
+    });
+
+    test('list default', () {
+      expect(GoatSerializer.fromMap({}).list, [34, 35]);
+    });
+  });
+}

angel_serialize_generator/test/models/game_pad.dart

@@ -3,7 +3,6 @@ import 'package:collection/collection.dart';
 import 'game_pad_button.dart';
 part 'game_pad.g.dart';
 
-
 @Serializable(autoIdAndDateFields: false)
 class _Gamepad {
   List<GamepadButton> buttons;

angel_serialize_generator/test/models/goat.dart

@@ -0,0 +1,12 @@
+import 'package:angel_serialize/angel_serialize.dart';
+import 'package:collection/collection.dart';
+part 'goat.g.dart';
+
+@Serializable(autoIdAndDateFields: false)
+abstract class _Goat {
+  @DefaultValue(34)
+  int get integer;
+
+  @DefaultValue([34, 35])
+  List<int> get list;
+}

angel_serialize_generator/test/models/goat.g.dart

@@ -0,0 +1,67 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'goat.dart';
+
+// **************************************************************************
+// JsonModelGenerator
+// **************************************************************************
+
+@generatedSerializable
+class Goat implements _Goat {
+  const Goat({this.integer: 34, List<int> this.list: const [34, 35]});
+
+  @override
+  final int integer;
+
+  @override
+  final List<int> list;
+
+  Goat copyWith({int integer, List<int> list}) {
+    return new Goat(integer: integer ?? this.integer, list: list ?? this.list);
+  }
+
+  bool operator ==(other) {
+    return other is _Goat &&
+        other.integer == integer &&
+        const ListEquality<int>(const DefaultEquality<int>())
+            .equals(other.list, list);
+  }
+
+  @override
+  int get hashCode {
+    return hashObjects([integer, list]);
+  }
+
+  Map<String, dynamic> toJson() {
+    return GoatSerializer.toMap(this);
+  }
+}
+
+// **************************************************************************
+// SerializerGenerator
+// **************************************************************************
+
+abstract class GoatSerializer {
+  static Goat fromMap(Map map) {
+    return new Goat(
+        integer: map['integer'] as int ?? 34,
+        list: map['list'] is Iterable
+            ? (map['list'] as Iterable).cast<int>().toList()
+            : const [34, 35]);
+  }
+
+  static Map<String, dynamic> toMap(_Goat model) {
+    if (model == null) {
+      return null;
+    }
+    return {'integer': model.integer, 'list': model.list};
+  }
+}
+
+abstract class GoatFields {
+  static const List<String> allFields = const <String>[integer, list];
+
+  static const String integer = 'integer';
+
+  static const String list = 'list';
+}