How to convert a String to Object in Flutter? - flutter

Question

I have two model classes Employee and AdditionalDetails
class Employee{
AdditionalDetails(this.uuid, this.additional_details);
String uuid;
String additional_details;
}
class AdditionalDetails{
AdditionalDetails(this.start, this.end, this.month);
String start;
String end;
String month;
}
And I have a handler in which I am creating objects of AdditionalDetails and pushing into a list.
List<Employee> list = new List<Employee>;
String add1 = AdditionalDetails("start1", "end1", "dec").toString();
String add2 = AdditionalDetails("start2", "end2", "jan").toString();
list.add(1, add1);
list.add(2, add2);
I am displaying these items in a list and on click of each item , I have to display other details in a dialog box.
I am able to get the uuid by iterating over the list but when doing json.decode(additional_details), it is giving this:
SyntaxError: Unexpected token I in JSON at position 0
How can I get the start, end and month properties from the additionalDetails?

Answer 1

I think this is what you want.
class Employee {
Employee(this.uuid, this.additionalDetails);
String uuid;
String additionalDetails;
}
class AdditionalDetails {
AdditionalDetails(
this.start,
this.end,
this.month,
);
final String start;
final String end;
final String month;
#override
String toString() => '$start $end $month';
}
final list = <Employee>[];
final add1 = AdditionalDetails("start1", "end1", "dec").toString();
final add2 = AdditionalDetails("start2", "end2", "jan").toString();
list.add(Employee('1', add1));
list.add(Employee('2', add2));
More cool way:
class Employee {
Employee({
#required this.uuid,
#required this.additionalDetails,
});
final String uuid;
final AdditionalDetails additionalDetails;
factory Employee.fromJson(Map<String, dynamic> json) => Employee(
uuid: json["uuid"],
additionalDetails: json["additionalDetails"],
);
Map<String, dynamic> toJson() => {
"uuid": uuid,
"additionalDetails": additionalDetails.toJson(),
};
}
class AdditionalDetails {
AdditionalDetails({
#required this.start,
#required this.end,
#required this.month,
});
final String start;
final String end;
final String month;
factory AdditionalDetails.fromJson(Map<String, dynamic> json) =>
AdditionalDetails(
start: json["start"],
end: json["end"],
month: json["month"],
);
Map<String, dynamic> toJson() => {
"start": start,
"end": end,
"month": month,
};
}
final list = <Employee>[];
final add1 = AdditionalDetails(start: "start1", end: "end1", month: "dec");
list.add(Employee(uuid: '1', additionalDetails: add1));
final json = add1.toJson(); // Map<String, dynamic>
final startFromJson = json['start'];
final object = AdditionalDetails.fromJson(json); // AdditionalDetails
final startFromObject = object.start;

Answer 2

if you want to create an object out of string instead of jsondecode you should use toJson and fromJson function:
class AdditionalDetails{
AdditionalDetails(this.start, this.end, this.month);
String start;
String end;
String month;
AdditionalDetails.fromJson(Map<String, dynamic> json){
this.start = json['start'];
this.end = json['end'];
this.month = json['month'];
}
Map<String, dynamic> toJson(){
Map<String, dynamic> data = {};
data['start'] = this.start;
data['end'] = this.end;
data['month'] = this.month;
return data;
}
}
List<Employee> list = new List<Employee>;
String add1 = AdditionalDetails("start1", "end1", "dec").toJson();
String add2 = AdditionalDetails("start2", "end2", "jan").toJson();
list.add(1, add1);
list.add(2, add2);
final object = AdditionalDetails.fromJson(add1);