json - built_value 如何将 json 数组反序列化为对象数组？

Question

在built_value的官方example显示如何设置对象的数组成员:

abstract class Collections implements Built<Collections, CollectionsBuilder> {
  static Serializer<Collections> get serializer => _$collectionsSerializer;

  BuiltList<int> get list;
  BuiltMap<String, int> get map;
  BuiltListMultimap<int, bool> get listMultimap;

  factory Collections([updates(CollectionsBuilder b)]) = _$Collections;
  Collections._();
}

它只是演示如何反序列化映射而不是数组，数组只是一个键/成员而不是数据本身。

但在某些情况下，我的 http 响应本身就是一个数组，而不是响应的成员。

我的模型:

abstract class Post implements Built<Post, PostBuilder> {
  static Serializer<Post> get serializer => _$postSerializer;
  int get userId;
  String get title;
  factory Post([updates(PostBuilder b)]) = _$Post;
  Post._();
}

我的要求是:

static Future<List<Post>> getPosts() async {
  final response = await http.get('https://jsonplaceholder.typicode.com/posts');
  if (response.statusCode == 200) {
    return serializers.deserialize(
        json.decode(response.body), 
        specifiedType: FullType(Post)
      );
  } else {
    throw Exception('Failed to load post');
  }
}

响应主体:

[
  {'userId': 1, 'title': 'title1'},
  {'userId': 2, 'title': 'title2'}
]

我查了所有的教程或者网络讨论，都没有提到这个场景，还是只能迭代response.body，一个一个反序列化成对象？例如:

static Future<List<Post>> getPosts() async {
  final response = await http.get('https://jsonplaceholder.typicode.com/posts');
  if (response.statusCode == 200) {
    final List<dynamic> data = json.decode(response.body);
    return data.map((m){
      return serializers.deserializeWith(Post.serializer, m);
    }).toList();
  } else {
    throw Exception('Failed to load post');
  }
}

Answer 1

根据@David Morgan 的 reply , built_value 还不支持反序列化列表。

Currently there’s no equivalent to deserializeWith for a list. You’ll need to deserialize one by one.