comparators 1.0.0

comparators: ^1.0.0 copied to clipboard

example/comparators_example.dart

import 'package:comparators/comparators.dart';
import 'package:comparators/extensions.dart';

final List<User> users = [
  const User(
    id: 0,
    username: 'JohnDoe',
    email: '[email protected]',
    isActive: false,
  ),
  const User(
    id: 1,
    username: 'Kathelie',
    email: '[email protected]',
    isActive: true,
  ),
  const User(
    id: 2,
    username: 'miX',
    email: '[email protected]',
    isActive: false,
  ),
  const User(
    id: 3,
    username: 'mr_cat',
    email: '[email protected]',
    isActive: false,
  ),
  const User(
    id: 4,
    username: 'Evan',
    email: '[email protected]',
    isActive: false,
  ),
  const User(
    id: 5,
    username: 'mitryp',
    email: '[email protected]',
    isActive: true,
  ),
];

void main() {
  _printUsers();

  // this will sort the list by the username field of the User object
  users.sort(compare((u) => u.username));

  _printUsers();

  // this will sort the users by their username
  // before comparing the usernames will be transformed with the provided transform
  // in this case, it will lowercase the names to do a case insensitive comparison
  users.sort(
    compareTransformed<User, String>(
        (u) => u.username, (name) => name.toLowerCase()),
  );

  _printUsers();

  // this will sort the users by their activity first, then by their email,
  // and then by their username
  users.sort(
    // the users which active is set to true will come first in the list
    compareBool<User>((u) => u.isActive).reversed.then(
          // then users will be sorted by their email field
          compare<User>((u) => u.email).then(
            // and then by their username
            compare<User>((u) => u.username),
          ),
        ),
  );

  _printUsers(trailing: '');
}

void _printUsers({String trailing = '\n'}) =>
    print('${users.join('\n')}$trailing');

/// A class representing a user with an id, username, email and activity status.
class User {
  final int id;
  final String username;
  final String email;
  final bool isActive;

  const User({
    required this.id,
    required this.username,
    required this.email,
    required this.isActive,
  });

  @override
  String toString() => 'User($id, $username, $email, active: $isActive)';
}