Talk about Dart (www.dartlang.org) and how it compares to JavaScript. Happened at the Java Usergroup in Stuttgart on 22.11.2012.

1. Dart != JavaScript
Christian Grobmeier
http://www.grobmeier.de
@grobmeier

2. Was ist falsch
an JavaScript?

3. JavaScript „false“:
false, 0, „“,
undefined, null
#1

4. Batterien selbst besorgen.
jQuery et al ist
Pflicht.
#2

5. Segen oder Fluch?
Keine Typen
#3

6. 1000 und 1 Möglichkeit
Vererbung
#4

7. Patterns helfen:
Namespace
#5

8. Jeder Browser
ist ein Individuum.
#6

9. Nicht nett.
var a1 = new Array(1,2,3,4,5);
var a2 = new Array(5);
#7

10. Einer für alle.
if( a === null || a === undefined)
#8

11. Fallstricke.
'' == '0' // false
0 == '' // true
0 == '0' // true
false == 'false' // false
false == '0' // true
#9
false == undefined // false
false == null // false
null == undefined // true
' trn ' == 0 // true

12. Darwin wusste es.
#10

13. Verkaufs-
argumente

14. Native VM
Dart Source
JavaScript
dart2js
Engine
Überall.

16. Pub

17. Nix neues.

18. Viele Libs.

19. Isolates.

20. Serverseitig.

21. JS -> Dart
Roadcrew.js
(https://github.com/grobmeier/Roadcrew.js

22. Use Case
<div class="page" id="tablePage">
<h1>Table Page</h1>
<a href="#otherPage">Other</a>
</div>
<div class="page" id="otherPage">
<h1>Other Page</h1>
<a href="#tablePage">Table</a>
</div>

23. function Roadcrew() { JavaScript
// Constructor
}
Roadcrew.prototype = {
// Prototyp
};
Roadcrew.prototype.act = function () {
// Function
Prototype
};
Roadcrew.another = function () {
// Static Function
};

24. class RoadcrewController {
var pages;
Dart
RoadcrewController() {
// Constructor
}
void act(e) {
// Method
Class
}
void static another() {
// Static method
}
}

25. JavaScript
Properties kopieren
Framework extend
Vererbung

26. Dart
class RoadcrewController
extends C {
...
}
class C {
Vererbung
}
...

27. Dart
class A implements B {
...
}
abstract class B {
Interfaces
...
}

28. JavaScript
function Roadcrew() {
test = „blub“;
var xyz = „bla“;
}
var act = function () {
Namespace
console.log(test);
};

29. Dart
library Roadcrew;
import 'dart:html';
part ,RoadcrewController.dart';
part 'RoadcrewInterceptor.dart';
Namespace
part 'RoadcrewException.dart';

30. JavaScript
var myobj = (function() {
var name = „CG“;
return {
getName = function() {
return name;
}
Privacy
}
}());

31. Dart
class Roadcrew {
var _name = „CG“;
_getTest() => name;
}
Privacy

32. JavaScript
var test = „Christian“;
test = true;
test = 10.32;
Types

33. Dart
class Roadcrew {
String _name = „CG“;
String _getTest() => name;
List<DivElement> pages;
}
Types

34. JavaScript
function RcErr(m,c,r){}
RcErr.prototype = new Error();
RcErr.prototype.constructor = RcErr;
try {
interceptor(d, data);
Exception
} catch (error) {
...
}

35. Dart
class RcEx {
String msg = "An error...";
int c;
RcEx(this.msg, [this.c = 1] );
}
try {
Exception
interceptors[pageId].act(d);
} on RcEx catch(e) { }

36. JavaScript
pages = $('.page');
page = $('#myPage');
DOM

37. Dart
pages = queryAll('.page');
page = query('#myPage');
DOM

38. JavaScript
$("a").live(
'click',
$.proxy(this, 'goto'));
DOM

39. Dart
queryAll('a').forEach((el) {
el.on.click.add((e) {
goto(e);
});
DOM
});

40. Batterien
beigelegt

41. import 'dart:isolate'; Dart
echo() {
port.receive((msg, reply) {
reply.send('I received: $msg');
});
}
main() {
var sendPort = spawnFunction(echo);
Isolates
sendPort.call('Hello').then((reply) {
print(reply);
});
}

42. Mehr?
Dart
I/O
JSON
Mirrors
Logging
...

43. Wo steht Dart?
Diskussion

44. Danke!
Christian Grobmeier
http://www.grobmeier.de
@grobmeier

45. Image Credits
Omikuji: Flickr (jessleecuizon)
Dollars: Flickr (401(K) 2012)
Pub: Flickr (ell brown)
Dog: Flickr (joshme17)
Package: Flickr (lemonhalf)
Threads: Flickr (The Big Quack)
Server: Flickr (getButterfly)
School Bus: Flickr (loop_oh)
Batteries: Flickr (scalespeeder)
Discussing Monks: Flickr (wonderlane)