Fetch user details from another model - django

Question

I have a model(Poll) which contains another model(User) with user details.
I want to get the Username of who posted a poll
but the below is error occurred
I/flutter (21892): type 'int' is not a subtype of type 'String'
this is my model class(flutter)
import 'dart:convert';
class Poll {
Poll({
required this.id,
required this.choices,
required this.question,
required this.pubDate,
required this.createdBy,
});
late final int id;
late final List<Choices> choices;
late final String question;
late final String pubDate;
late final User createdBy;
Poll.fromJson(Map<String, dynamic> json) {
id = json['id'];
choices =
List.from(json['choices']).map((e) => Choices.fromJson(e)).toList();
question = json['question'];
pubDate = json['pub_date'];
createdBy = User.fromJson(jsonDecode(json['created_by']));
}
Map<String, dynamic> toJson() {
final _data = <String, dynamic>{};
_data['id'] = id;
_data['choices'] = choices.map((e) => e.toJson()).toList();
_data['question'] = question;
_data['pub_date'] = pubDate;
_data['created_by'] = createdBy.toJson();
return _data;
}
}
class Choices {
Choices({
required this.id,
required this.choiceText,
required this.poll,
});
late final int id;
late final String choiceText;
late final int poll;
Choices.fromJson(Map<String, dynamic> json) {
id = json['id'];
choiceText = json['choice_text'];
poll = json['poll'];
}
Map<String, dynamic> toJson() {
final _data = <String, dynamic>{};
_data['id'] = id;
_data['choice_text'] = choiceText;
_data['poll'] = poll;
return _data;
}
}
class User {
User({
required this.id,
required this.password,
required this.lastLogin,
required this.isSuperuser,
required this.username,
required this.firstName,
required this.lastName,
required this.email,
required this.isStaff,
required this.isActive,
required this.dateJoined,
required this.groups,
required this.userPermissions,
});
late final int id;
late final String password;
late final String lastLogin;
late final bool isSuperuser;
late final String username;
late final String firstName;
late final String lastName;
late final String email;
late final bool isStaff;
late final bool isActive;
late final String dateJoined;
late final List<dynamic> groups;
late final List<dynamic> userPermissions;
User.fromJson(Map<String, dynamic> json) {
id = json['id'];
password = json['password'];
lastLogin = json['last_login'];
isSuperuser = json['is_superuser'];
username = json['username'];
firstName = json['first_name'];
lastName = json['last_name'];
email = json['email'];
isStaff = json['is_staff'];
isActive = json['is_active'];
dateJoined = json['date_joined'];
groups = List.castFrom<dynamic, dynamic>(json['groups']);
userPermissions = List.castFrom<dynamic, dynamic>(json['user_permissions']);
}
Map<String, dynamic> toJson() {
final _data = <String, dynamic>{};
_data['id'] = id;
_data['password'] = password;
_data['last_login'] = lastLogin;
_data['is_superuser'] = isSuperuser;
_data['username'] = username;
_data['first_name'] = firstName;
_data['last_name'] = lastName;
_data['email'] = email;
_data['is_staff'] = isStaff;
_data['is_active'] = isActive;
_data['date_joined'] = dateJoined;
_data['groups'] = groups;
_data['user_permissions'] = userPermissions;
return _data;
}
}
here is how I am parsing the json
List<Poll> _polls = [];
Future<bool> getOffers() async {
var url = Uri.parse(polls_uri);
try {
http.Response response = await http.get(url);
var data = json.decode(response.body);
List<Poll> temp = [];
for (var element in data) {
Poll poll = Poll.fromJson(element);
temp.add(poll);
}
_polls = temp;
return true;
} catch (e) {
print(e);
return false;
}
}
List<Poll> get polls {
return [..._polls];
}
this is where i want to display I want to display the details
ListView.builder(
itemCount: polls.length,
itemBuilder: (BuildContext context, int index) {
return Card(
child: Padding(
padding: EdgeInsets.all(16.0),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Text(polls[index].question),
Text(polls[index].createdBy.username),
]),
),
);
},
),
my model class(django)
class Poll(models.Model):
question = models.CharField(max_length=100)
created_by = models.ForeignKey(User, on_delete=models.CASCADE)
pub_date = models.DateTimeField(auto_now=True)
def __str__(self):
return self.question
serializer
class PollSerializer(serializers.ModelSerializer):
choices = ChoiceSerializer(many=True, read_only=True, required = False)
class Meta:
model = Poll
fields = '__all__'
class UserSerializer(serializers.ModelSerializer):
class Meta:
model = User
fields = '__all__'
views
class PollList(generics.ListCreateAPIView):
queryset = Poll.objects.all() [:20]
serializer_class = PollSerializer
Poll Json data: the key "created_by" is a model of class user... It is from the class I want to get the username
{
"id": 3,
"choices": [
{
"id": 9,
"choice_text": "Day",
"poll": 3
},
{
"id": 10,
"choice_text": "Boarding",
"poll": 3
},
{
"id": 11,
"choice_text": "Mixed",
"poll": 3
}
],
"created_by": 1,
"question": "Type of School: Day or Boarding",
"pub_date": "2022-07-21T13:29:23.445097Z"
},