Flutter failed to post data to create user with API - flutter

Question

I try to create user using api but it throws an exception when executed.
So, here is my json response as below.
{
"success": 1,
"user": {
"user_id": "612f02fc4ae19",
"name": "Test User3",
"mobile": "8347406873",
"email": "dhaval#gmail.com",
"standard_id": "5d1594e283e1a",
"medium_id": "5d15938aa1344",
"location": "Vyara",
"created_at": "2021-09-01"
},
"msg": "Your account has been created successfully."
}
As response i created model class as below in signup_model.dart file.
import 'dart:convert';
SignupModel signupModelFromJson(String str) =>
SignupModel.fromJson(json.decode(str));
String signupModelToJson(SignupModel data) => json.encode(data.toJson());
class SignupModel {
SignupModel({
this.success,
this.user,
this.msg,
});
int? success;
UserRegistration? user;
String? msg;
factory SignupModel.fromJson(Map<String, dynamic> json) => SignupModel(
success: json["success"],
user: UserRegistration.fromJson(json["user"]),
msg: json["msg"],
);
Map<String, dynamic> toJson() => {
"success": success,
"user": user?.toJson(),
"msg": msg,
};
}
class UserRegistration {
UserRegistration({
this.userId,
this.name,
this.mobile,
this.email,
this.standardId,
this.mediumId,
this.location,
this.createdAt,
});
String? userId;
String? name;
String? mobile;
String? email;
String? standardId;
String? mediumId;
String? location;
DateTime? createdAt;
factory UserRegistration.fromJson(Map<String, dynamic> json) =>
UserRegistration(
userId: json["user_id"],
name: json["name"],
mobile: json["mobile"],
email: json["email"],
standardId: json["standard_id"],
mediumId: json["medium_id"],
location: json["location"],
createdAt: DateTime.parse(json["created_at"]),
);
Map<String, dynamic> toJson() => {
"user_id": userId,
"name": name,
"mobile": mobile,
"email": email,
"standard_id": standardId,
"medium_id": mediumId,
"location": location,
"created_at":
"${createdAt?.year.toString().padLeft(4, '0')}-${createdAt?.month.toString().padLeft(2, '0')}-${createdAt?.day.toString().padLeft(2, '0')}",
};
}
Function which i created as below in api_manager.dart file.
Future<UserRegistration> createUser(
String name,
String email,
String mobile,
String standardId,
String mediumId,
) async {
final registrationUrl = "$baseUrl/user/register";
final response = await http.post(
Uri.parse(registrationUrl),
headers: <String, String>{
'Content-Type': 'application/json; charset=UTF-8',
},
body: jsonEncode(<String, String>{
'name': name,
'email': email,
'mobile': mobile,
'standard_id': standardId,
'medium_id': mediumId,
}),
);
if (response.statusCode == 200) {
print(response.body);
return UserRegistration.fromJson(jsonDecode(response.body));
} else {
throw Exception('Failed to create User.');
}
}
And My signup screen Code as below in signup_screen.dart file.
class _SignUp1State extends State<SignUp1> {
final baseUrl = SankalpApi().baseUrl;
bool value = false;
var _standards = <Standard>[];
var _mediums = <Medium>[];
Standard? selectedStandard;
Medium? selectedMedium;
var standardId;
var mediumId;
final TextEditingController _nameController = TextEditingController();
final TextEditingController _emailController = TextEditingController();
final TextEditingController _mobileController = TextEditingController();
Future<UserRegistration>? userRegistration;
GlobalKey<FormState> _globalFormKey = GlobalKey<FormState>();
bool isApiCallProcess = false;
#override
void initState() {
super.initState();
ApiManager().getStandards().then((standards) {
setState(() {
_standards = standards;
});
});
}
void onMediumChange(standard) {
setState(() {
selectedStandard = standard;
_mediums = [];
});
String mediumUrl =
"$baseUrl/medium/get_by_course_id?standard_id=${selectedStandard?.standardId}";
ApiManager().getMediums(mediumUrl).then((List<Medium> value) => {
setState(() {
_mediums = value;
})
});
}
#override
Widget build(BuildContext context) {
final Shader linearGradient = LinearGradient(
colors: <Color>[
Color(0xff8921aa),
Color(0xffDA44bb),
],
).createShader(new Rect.fromLTWH(0.0, 0.0, 200.0, 70.0));
return SingleChildScrollView(
child: Form(
key: _globalFormKey,
child: Container(
padding: EdgeInsets.all(12),
child: Column(
children: [
SizedBox(height: 30),
Text(
'Learn from wide range of videos and tutorials',
textAlign: TextAlign.center,
style: GoogleFonts.openSans(
fontSize: 15,
color: Colors.grey[600],
),
),
TextFormField(
decoration: InputDecoration(labelText: "Full Name"),
controller: _nameController,
validator: (value) {
if (value!.isEmpty) {
return "Name is required.";
}
return null;
},
onSaved: (value) {
//this.userRegistration.name = value.toString().trim();
},
),
SizedBox(height: 10),
TextFormField(
decoration: InputDecoration(labelText: "Email"),
controller: _emailController,
validator: (value) {
if (value!.isEmpty) {
return 'Email is required.';
}
if (!RegExp("^[a-zA-Z0-9+_.-]+#[a-zA-Z0-9.-]+.[a-z]")
.hasMatch(value)) {
return 'Enter valid Email';
}
return null;
},
onSaved: (value) {
//this.userRegistration.email = value.toString().trim();
},
),
SizedBox(height: 10),
TextFormField(
decoration: InputDecoration(labelText: "Mobile Number"),
controller: _mobileController,
validator: (value) {
String pattern = r'(^[0-9]*$)';
RegExp regExp = new RegExp(pattern);
if (value!.length == 0) {
return "Mobile is required";
} else if (value.length != 10) {
return "Mobile number must 10 digits";
} else if (!regExp.hasMatch(value)) {
return "Mobile Number must be digits";
}
return null;
},
onSaved: (value) {
//this.userRegistration.mobile = value.toString().trim();
},
),
SizedBox(height: 20),
DropdownButtonFormField<Standard>(
validator: (value) {
if (value == null) {
return "Select Standard";
}
},
isExpanded: true,
hint: Text('Select Standard'),
value: selectedStandard,
items: _standards.map((Standard standard) {
return DropdownMenuItem<Standard>(
value: standard,
child: Text(standard.standardName),
);
}).toList(),
onSaved: (value) {
selectedStandard = value;
//this.userRegistration.standardId = value!.standardId;
},
onChanged: (val) {
setState(() {
selectedStandard = val;
standardId = val?.standardId;
// print("StandardId : ${val?.standardId}");
// print("StandardId : ${val?.standardName}");
onMediumChange(val);
});
},
),
SizedBox(height: 20),
DropdownButtonFormField<Medium>(
validator: (value) {
if (value == null) {
return "Select Medium";
}
},
isExpanded: true,
hint: Text('Select Medium'),
value: selectedMedium,
items: _mediums.map((Medium medium) {
return DropdownMenuItem<Medium>(
value: medium,
child: Text(medium.mediumName),
);
}).toList(),
onSaved: (value) {
selectedMedium = value;
//this.userRegistration.mediumId = value!.mediumId;
},
onChanged: (val) {
setState(() {
selectedMedium = val;
mediumId = val?.mediumId;
// print("Medium id : ${val?.mediumId}");
// print("Medium id : ${val?.mediumName}");
});
}),
SizedBox(
height: 30,
),
Row(
mainAxisAlignment: MainAxisAlignment.end,
children: [
ElevatedButton(
onPressed: () {
if (validateAndSave()) {
setState(() {
this.isApiCallProcess = true;
print(_nameController.text);
print(_emailController.text);
print(_mobileController.text);
print(standardId);
print(mediumId);
userRegistration = ApiManager().createUser(
_nameController.text,
_emailController.text,
_mobileController.text,
standardId,
mediumId,
);
});
}
},
style: ElevatedButton.styleFrom(
padding: EdgeInsets.zero,
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.circular(25))),
child: Ink(
decoration: BoxDecoration(
gradient: LinearGradient(
colors: [
const Color(0xff8921aa),
const Color(0xffDA44bb),
],
),
borderRadius: BorderRadius.circular(25)),
child: Container(
width: 100,
height: 50,
alignment: Alignment.center,
child: Text(
'SIGNUP',
style: TextStyle(
fontSize: 15,
),
),
),
),
),
],
),
SizedBox(
height: 60,
),
Text('Already have an account?'),
TextButton(
onPressed: () {
Navigator.push(context,
MaterialPageRoute(builder: (context) => Login2()));
},
child: Text(
'Login',
style: TextStyle(
fontSize: 18,
fontWeight: FontWeight.bold,
foreground: new Paint()..shader = linearGradient,
),
),
)
],
),
),
),
);
}
bool validateAndSave() {
final form = _globalFormKey.currentState;
if (form!.validate()) {
form.save();
return true;
}
return false;
}
}
So, when i try to sign up it thorows an Exception as below.
So what is the problem in given code.?