CODEWITHSUNDEEP
jsonflutterlistviewflutter-listview
Kevnlan
Kevnlan

Reputation: 567

Getting error of type 'List<dynamic>' is not a subtype of type 'Map<String, dynamic>'

I am creating a flutter app to display users in a list. I can fetch and print the data however I cannot display the data since I get this error Exception has occurred. _TypeError (type 'List<dynamic>' is not a subtype of type 'Map<String, dynamic>')

I used dio package to fetch the data. Here is the code used to make the api call

class DioClient {
  final Dio _dio = Dio();

  final _farmerUrl = 'https://retoolapi.dev/Rzl99e/farmers';

  Future<Users?> getUser() async {
    Users? users;
    try {
      Response userData = await _dio.get(_farmerUrl);
      print('User Info: ${userData.data}');
      users = Users.fromJson(userData.data);
    } on DioError catch (e) {
      if (e.response != null) {
        print('Dio error!');
      } else {
        print('Error sending request! '+ e.message);
      }
    }
    return users;
  }  
}

This is the model class I use to parse the json response

List<Users> usersFromJson(String str) => List<Users>.from(json.decode(str).map((x) => Users.fromJson(x)));

String usersToJson(List<Users> data) => json.encode(List<dynamic>.from(data.map((x) => x.toJson())));

class Users {
    Users({
        this.id,
        this.bio,
        this.email,
        this.lastName,
        this.firstName,
        this.phoneNumber,
        this.memberNumber,
    });

    int? id;
    String? bio;
    String? email;
    String? lastName;
    String? firstName;
    String? phoneNumber;
    String? memberNumber;

    factory Users.fromJson(Map<String, dynamic> json) => Users(
        id: json["id"],
        bio: json["bio"],
        email: json["email"],
        lastName: json["last_name"],
        firstName: json["first_name"],
        phoneNumber: json["phone_number"],
        memberNumber: json["member_number"],
    );

    Map<String, dynamic> toJson() => {
        "id": id,
        "bio": bio,
        "email": email,
        "last_name": lastName,
        "first_name": firstName,
        "phone_number": phoneNumber,
        "member_number": memberNumber,
    };
}

This is the code I am using to display the list of users

      body: SingleChildScrollView(
        child: Center(
          child: FutureBuilder<Users?>(
            future: _client.getUser(),
            builder: (context, snapshot) {
              if (snapshot.hasData) {
                Users? userInfo = snapshot.data;
                if (userInfo != null) {
                  return ListTile(
                    title: Text(userInfo.firstName! + ' ' + userInfo.lastName!),
                    subtitle: Text(userInfo.phoneNumber!),
                  );
                }
              }
              return CircularProgressIndicator();
            },
          ),
        ),
      ),

What can I change so as to fully display the user list.

Upvotes: 0

Views: 276

Answers (1)

Jahidul Islam
Jahidul Islam

Reputation: 12565

Decode your data and store it in list format because your API return list data

return UserRes.fromJsonMap(jsonDecode(userData.data));

Create response class for user list

class UserRes{
  List<Users> content;

  UserRes.fromJsonMap(dynamic data)
      : content = List<Users>.from(
      data.map((sat) => Users.fromJson(sat)));
}

And call API like and your future will return list response:

 final _farmerUrl = 'https://retoolapi.dev/Rzl99e/farmers';

  Future<UserRes> getUser() async {
    try {
      Response userData = await _dio.get(_farmerUrl);
      print('User Info: ${userData.data}');
      return UserRes.fromJsonMap(jsonDecode(userData.data));
    } on DioError catch (e) {
      if (e.response != null) {
        print('Dio error!');
      } else {
        print('Error sending request! '+ e.message);
      }
    }
  }

you can call from UI

body: SingleChildScrollView(
        child: Center(
          child: FutureBuilder<Users?>(
            future: _client.getUser(),
            builder: (context, snapshot) {
              if (snapshot.hasData) {
                List<Users>? userInfo = snapshot.data;
                if (userInfo != null) {
                  return ListTile( // your data is list format you can bind with listBuilder 
                    title: Text(userInfo.first.firstName! + ' ' + userInfo.first.lastName!),
                    subtitle: Text(userInfo.first.phoneNumber!),
                  );
                }
              }
              return CircularProgressIndicator();
            },
          ),
        ),
      ),

Upvotes: 2

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