Pirate Name Badge Dart

piratebadge.dart

// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

import 'dart:html';
import 'dart:math' show Random;
import 'dart:convert' show JSON;

ButtonElement genButton;
final String TREASURE_KEY = 'pirateName';

void main() {
  querySelector('#inputName').onInput.listen(updateBadge);
  genButton = querySelector('#generateButton');
  genButton.onClick.listen(generateBadge);
  setBadgeName(getBadgeNameFromStorage());
}

void updateBadge(Event e) {
  String inputName = (e.target as InputElement).value;
  setBadgeName(new PirateName(firstName: inputName));
  if (inputName.trim().isEmpty) {
    genButton..disabled = false
             ..text = 'Aye! Gimme a name!';
  } else {
    genButton..disabled = true
             ..text = 'Arrr! Write yer name!';
  }
}

void setBadgeName(PirateName newName) {
  if (newName == null) {
    return;
  }
  querySelector('#badgeName').text = newName.pirateName;
  window.localStorage[TREASURE_KEY] = newName.jsonString;
}

PirateName getBadgeNameFromStorage() {
  String storedName = window.localStorage[TREASURE_KEY];
  if (storedName != null) {
    return new PirateName.fromJSON(storedName);
  } else {
    return null;
  }
}

void generateBadge(Event e) {
  setBadgeName(new PirateName());
}

class PirateName {
  static final Random indexGen = new Random();
  String _firstName;
  String _appellation;
  
  static final List names = [
    'Anne', 'Mary', 'Jack', 'Morgan', 'Roger',
    'Bill', 'Ragnar', 'Ed', 'John', 'Jane'];
  static final List appellations = [
    'Jackal', 'King', 'Red', 'Stalwart', 'Axe',
    'Young', 'Brave', 'Eager', 'Wily', 'Zesty'];
  
  PirateName({String firstName, String appellation}) {
    if (firstName == null) {
      _firstName = names[indexGen.nextInt(names.length)];
    } else {
      _firstName = firstName;
    }
    if (appellation == null) {
      _appellation = appellations[indexGen.nextInt(appellations.length)];
    } else {
      _appellation = appellation;
    }
  }
  
  String get pirateName =>
          _firstName.isEmpty ? '' : '$_firstName the $_appellation';
  String toString() => pirateName;
  
  PirateName.fromJSON(String jsonString) {
    Map storedName = JSON.decode(jsonString);
    _firstName = storedName['f'];
    _appellation = storedName['a'];
  }
  
  String get jsonString => JSON.encode({"f": _firstName, "a": _appellation});
}