How does built_value deserialize json array to object array?

Question

In built_value's official example show how to setup an array member of an object:

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._();
}

it just demonstrate how to deserialize a map but not array, the array just a key/member not the data itself.

but in may case, my http response is an array itself, not play as a member of the response.

my model:

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._();
}

my request is:

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');
  }
}

response.body:

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

I looked up every tutorial or network discussion, no one mentions this scenario, or should I can only iterate the response.body and deserialize to object one by one? for example:

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

according to @David Morgan 's reply, built_value is not support deserialize a list yet.

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