Error: Expected a value of type '(String, dynamic) => void', but got one of type '(dynamic) => Null'

Question

My first project and newbie to flutter, unable to solve this after 2 weeks of trying.

I am trying to get request via API using GetX package and i got the error mentioned above.

Trying to parse JsonMap into a List and it's giving me the error mentioned.

I have tested and the StatusCode is 200, I am assuming its just not parsing correctly.

Thanks in advance!

Peace JY

Error message: -

Error: Expected a value of type '(String, dynamic) => void', but got one of type '(dynamic) => Null'  

Controller:-

class BlogController extends GetxController {
  final BlogRepo blogRepo;

  BlogController({required this.blogRepo});

  List<dynamic> _blogList = [];
  List<dynamic> get blogList => _blogList;

  Future<void> getBlogList() async {
    Response response = await blogRepo.getBlogList();

    if (response.statusCode == 200) {
      print("Got Data");        //this gets printed  
      _blogList = [];
      _blogList.addAll(Blog.fromJson(response.body).data);
      print(_blogList);       // not printing _blogList
      update();
     
    } else {}
  }
}

Model:-

class Blog {
  late List<Data> _data;
  List<Data> get data => _data;

  Blog({required data}) {
    this._data = data;
  }
  Blog.fromJson(Map<String, dynamic> json) {
    if (json['data'] != null) {
      _data = <Data>[];
      json['data'].forEach(
        (v) {
          _data.add(Data.fromJson(v));
        },
      );
    }
  }
}



class Data {
  int? id;
  Attributes? attributes;

  Data({this.id, this.attributes});

  Data.fromJson(Map<String, dynamic> json) {
    id = json['id'];
    attributes = json['attributes'] != null
        ? Attributes.fromJson(json['attributes'])
        : null;
  }
}


class Attributes {
  String? title;
  String? createdAt;
  String? updatedAt;
  String? publishedAt;
  String? text;
  String? link;
  Image? image;

  Attributes(
      {this.title,
      this.createdAt,
      this.updatedAt,
      this.publishedAt,
      this.text,
      this.link,
      this.image});

  Attributes.fromJson(Map<String, dynamic> json) {
    title = json['title'];
    createdAt = json['createdAt'];
    updatedAt = json['updatedAt'];
    publishedAt = json['publishedAt'];
    text = json['text'];
    link = json['link'];
    image = json['image'] != null ? Image.fromJson(json['image']) : null;
  }
}


class Image {
  Data? data;

  Image({this.data});

  Image.fromJson(Map<String, dynamic> json) {
    data = json['data'] != null ? Data.fromJson(json['data']) : null;
  }
}


class NestedAttributes {
  String? name;
  String? alternativeText;
  String? caption;
  int? width;
  int? height;
  Formats? formats;
  String? hash;
  String? ext;
  String? mime;
  double? size;
  String? url;
  Null? previewUrl;
  String? provider;
  Null? providerMetadata;
  String? createdAt;
  String? updatedAt;

  NestedAttributes(
      {this.name,
      this.alternativeText,
      this.caption,
      this.width,
      this.height,
      this.formats,
      this.hash,
      this.ext,
      this.mime,
      this.size,
      this.url,
      this.previewUrl,
      this.provider,
      this.providerMetadata,
      this.createdAt,
      this.updatedAt});

  NestedAttributes.fromJson(Map<String, dynamic> json) {
    name = json['name'];
    alternativeText = json['alternativeText'];
    caption = json['caption'];
    width = json['width'];
    height = json['height'];
    formats =
        json['formats'] != null ? Formats.fromJson(json['formats']) : null;
    hash = json['hash'];
    ext = json['ext'];
    mime = json['mime'];
    size = json['size'];
    url = json['url'];
    previewUrl = json['previewUrl'];
    provider = json['provider'];
    providerMetadata = json['provider_metadata'];
    createdAt = json['createdAt'];
    updatedAt = json['updatedAt'];
  }
}


class Formats {
  Thumbnail? thumbnail;
  Thumbnail? large;
  Thumbnail? medium;
  Thumbnail? small;

  Formats({this.thumbnail, this.large, this.medium, this.small});

  Formats.fromJson(Map<String, dynamic> json) {
    thumbnail = json['thumbnail'] != null
        ? Thumbnail.fromJson(json['thumbnail'])
        : null;
    large = json['large'] != null ? Thumbnail.fromJson(json['large']) : null;
    medium = json['medium'] != null ? Thumbnail.fromJson(json['medium']) : null;
    small = json['small'] != null ? Thumbnail.fromJson(json['small']) : null;
  }
}


class Thumbnail {
  String? name;
  String? hash;
  String? ext;
  String? mime;
  int? width;
  int? height;
  double? size;
  Null? path;
  String? url;

  Thumbnail(
      {this.name,
      this.hash,
      this.ext,
      this.mime,
      this.width,
      this.height,
      this.size,
      this.path,
      this.url});

  Thumbnail.fromJson(Map<String, dynamic> json) {
    name = json['name'];
    hash = json['hash'];
    ext = json['ext'];
    mime = json['mime'];
    width = json['width'];
    height = json['height'];
    size = json['size'];
    path = json['path'];
    url = json['url'];
  }
}

Answer 1

Try using response.data instead of response.body when you got the response.