I have a simple class named Person, having three fields name, country and birthdate.

here I want to make a getter that returns a list of persons whose birthday is coming to this week.

and one more thing that I am getting error:

Person class contains a field named birthday which type is DateTime

How to assign value to DateTime?. I am doing as following which showing an error with birthday field

Person(name: 'Alex',country: 'Zambia',birthdate: '12-09-1990'),

class Person
{
  String name;
  String country;
  DateTime birthdate;
  
  Person({required this.name,required this.country,required this.birthdate});
  
}

and here is the code where I will use this getter for displaying user list

class myscreen extends StatelessWidget {
   myscreen({Key? key}) : super(key: key);



  List<Person> personlist=[
    Person(name: 'Alex',country: 'Zambia',birthdate: '12-09-1990'),
    Person(name: 'Suzi',country: 'Laos',birthdate: '14-08-1980'),
    Person(name: 'Lyli', country: 'Nepal', birthdate: '27-09-2002'),
  ];

  List<Person> get person_birthday_thisweek{
    List<Person> templist=[];

    //what to code to get the list of persons whose birthday is in this week

    return templist;
  }

CodePudding user response：

try this.. and use this package for DateTime format

CodePudding user response：

i update it for month end date in dart you can parse string to datetime DateTime.parse('1900-10-08 00:00:00.000')

List<Person> get person_birthday_thisweek{
List<Person> personlist = [
    Person(name: 'PPP',country: 'Zambia',birthdate: DateTime.parse('1900-10-08 00:00:00.000')),
    Person(name: 'LLL',country: 'Zambia',birthdate: DateTime.parse('1900-09-29 00:00:00.000')),
    Person(name: 'Alex',country: 'Zambia',birthdate: DateTime.parse('1990-10-03 00:00:00.000')),
    Person(name: 'Suzi',country: 'Laos',birthdate: DateTime.parse('1980-08-14 00:00:00.000')),
    Person(name: 'Lyli', country: 'Nepal', birthdate: DateTime.parse('2002-09-27 00:00:00.000')),
  ];
  List<Person> templist=[];
  var now = DateTime.now();
  //now = DateTime.parse("2022-10-01 13:13:40.305728");
  print(now);
  var start = now.day - now.weekday;
  var lst = List.generate(7, (index) => DateTime(now.year, now.month, start   index));
  for (var p in personlist) {
    var fakeDate = DateTime(now.year, p.birthdate.month, p.birthdate.day);
    if (lst.contains(fakeDate)) {
      print(p.name);
      templist.add(p);
    }
  }
  return templist;
}

CodePudding user response：

For you first issue you can convert your string to DateTime by using intl package, like this:

DateTime tempDate = new DateFormat("dd-MM-yyyy")
        .parse('12-09-1990');

but let assume your list is like this:

List<Person> personlist = [
    Person(name: 'Alex', country: 'Zambia', birthdate: DateTime(1990, 09, 12)),
    Person(name: 'Suzi', country: 'Laos', birthdate: DateTime(1980, 08, 14)),
    Person(name: 'Lyli', country: 'Nepal', birthdate: DateTime(2002, 09, 27)),
    Person(name: 'Lysadli', country: 'Nepal', birthdate: DateTime(2022, 10, 03))
  ];

so change your get method to this:

List<Person> get person_birthday_thisweek {
    final date = DateTime.now();
    DateTime startDate =
        getDate(date.subtract(Duration(days: date.weekday - 1)));
    DateTime endDate =
        getDate(date.add(Duration(days: DateTime.daysPerWeek - date.weekday)));

  List<Person> templist = personlist
    .where((element) =>
        (startDate.isBefore(element.birthdate) ||
            startDate == element.birthdate) &&
        endDate.isAfter(element.birthdate))
    .toList();

  return templist;
}

the result would be:

for (var element in person_birthday_thisweek) {
  print("object = ${element.birthdate}");
}
//2022-10-03 00:00:00.000