Flutter: Parsing JSON data and showing in App - flutter

Question

I am very new to Flutter and Dart.
I have a signup page and I would like to show error in the App. My backend page is returning the errors and status in JSON format. Like below.
{"errors":{"Password1":"Password could not be empty",
"Email1":"Invalid Email Format",
"Name":"Your name must be between 3 to 30 characters!"},
"success":false}
I created a file for JSON parsing like below.
import 'dart:convert';
Signup signupFromJson(String str) => Signup.fromJson(json.decode(str));
String signupToJson(Signup data) => json.encode(data.toJson());
class Signup {
Errors errors;
bool success;
Signup({
this.errors,
this.success,
});
factory Signup.fromJson(Map<String, dynamic> json) => Signup(
errors: Errors.fromJson(json["errors"]),
success: json["success"],
);
Map<String, dynamic> toJson() => {
"errors": errors.toJson(),
"success": success,
};
}
class Errors {
String password1;
String email1;
String name;
Errors({
this.password1,
this.email1,
this.name,
});
factory Errors.fromJson(Map<String, dynamic> json) => Errors(
password1: json["Password1"],
email1: json["Email1"],
name: json["Name"],
);
Map<String, dynamic> toJson() => {
"Password1": password1,
"Email1": email1,
"Name": name,
};
}
Now I need to show this data to App after Async call.
Future userRegistration() async{
try{
// Showing CircularProgressIndicator.
setState(() {
visible = true ;
});
// Getting value from Controller
String name = nameController.text;
String email = emailController.text;
String password = passwordController.text;
// SERVER API URL
var url = 'http://192.168.100.10:8080/app/registerexec.php';
// Store all data with Param Name.
var data = {'name': name, 'email': email, 'password' : password};
// Starting Web API Call.
var response = await http.post(url, body: json.encode(data));
// Getting Server response into a variable.
final message = signupFromJson(response.body);
if(response.statusCode == 200){
setState(() {
visible = false;
});
}
// Showing Alert with Response JSON Message.
}catch(e){
return userRegistration();
}
}
How can I show the JSON data to SnackBar?
Edit
I managed to get the data in Print after manually defining it. Like below. But I want to automate it. So, if there are any errors it can show and if its successful then a different message.
print(message.errors.email1);
print(message.errors.name);
print(message.errors.password1);
print(message.success);

Answer 1

you could use FutureBuilder at your snackBar. I've edited from the code available here:
class SnackBarPage extends StatelessWidget {
#override
Widget build(BuildContext context) {
return FutureBuilder(
future: userRegistration,
initialData: '',
builder: (BuildContext context, AsyncSnapshot snapshot) {
if (snapshot.hasData) {
// snapshot.data = yourData from your userRegistration
// print(snapshot.data) to show your data here
return snackBar = SnackBar(
content: Text('Yay! A SnackBar!'),
action: SnackBarAction(
label: 'Undo',
onPressed: () {
},
)
};
)
},
),
}
}