Introductory Tech Talk on Dart. Presented at the GDG Aachen Dart Flight School. Based on the slides by Seth Ladd: http://goo.gl/EbY4uS

1. Welcome
#flydart #gdgac

2. #flydart #gdgac

3. Introduction to
Based on the Slides by Seth Ladd
#flydart #gdgac

4. Who am I?
Sebastian Mauer aka
GDG Aachen Co-Lead
CS Student
Software Engineer
I don’t work for Google …yet
#flydart #gdgac

5. #flydart #gdgac

6. is about two things:
✔ Improved productivity
✔ Increased performance
#flydart #gdgac

7. Learn the language in under one hour.
(we have the whole day)
#flydart #gdgac

8. Use the tools
you already know
IntelliJ
Sublime
Eclipse (DartEditor)
#flydart #gdgac

9. Compile to JavaScript
(runs across the modern web)
#flydart #gdgac

10. Run Dart on the server
with the Dart VM
#flydart #gdgac

11. Jasmine
Docs
PhantomJS
Docs
dest templates
Docs
moment.js
Docs
Modernizr
Docs
jQuery
Docs
Backbone Marionette
Docs
Backbone
Docs
require.js
Docs
#flydart #gdgac

12. Packages
Clear and consistent
Intl
Polymer
Unit test
Dart SDK
#flydart #gdgac

13. Apps start small, but grow and scale
#flydart #gdgac

14. Simple syntax, ceremony free
class Hug {
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Familiar

15. Simple syntax, ceremony free
class Hug {
num strength;
Hug(this.strength);
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Terse

16. Simple syntax, ceremony free
class Hug {
num strength;
Hug(this.strength);
!
Hug operator +(Hug other) {
return new Hug(strength +
other.strength);
}
#flydart #gdgac
Operator overriding

17. Simple syntax, ceremony free
class Hug {
num strength;
Hug(this.strength);
!
Hug operator +(Hug other) {
return new Hug(strength + other.strength);
}
!
void patBack({int hands: 1}) {
// ...
}
#flydart #gdgac
Named, optional params
w/ default value

18. Simple syntax, ceremony free
…
Hug operator +(Hug other) {
return new Hug(strength + other.strength);
}
!
void patBack({int hands: 1}) {
// ...
}
!
String toString() => "Embraceometer reads $strength";
One-line Function
#flydart #gdgac

19. Simple syntax, ceremony free
…
Hug operator +(Hug other) {
return new Hug(strength + other.strength);
}
!
void patBack({int hands: 1}) {
// ...
}
!
String toString() => "Embraceometer reads $strength";
String interpolation
#flydart #gdgac

20. #flydart #gdgac

21. #flydart #gdgac

22. Clean semantics and behavior
Examples
•
Only true is truthy
•
There is no undefined, only null
•
No type coercion with ==, +
#flydart #gdgac

23. Clean semantics and behavior
"hello".missing / ??
/
Class 'String' has no instance getter 'missing'
NoSuchMethodError : method not found: ‚missing'
Receiver: "hello"
Arguments: []
LOGICAL!
#flydart #gdgac

24. Clean semantics and behavior
'hello' > 1 / ??
/
Class 'String' has no instance method '>'.
LOGICAL!
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25. Clean semantics and behavior
Variable scope?
var foo = 'top-level';
!
main() {
if (true) { var foo = 'inside'; }
!
}
print(foo); / ?? What will this print?
/
top-level
NO HOISTING!
LOGICAL!
#flydart #gdgac

26. Clean semantics and behavior
Scope of „this“?
class AwesomeButton {
!
AwesomeButton(button) {
button.onClick.listen((Event e) => this.atomicDinosaurRock());
}
!
}
atomicDinosaurRock() {
/* ... */
}
LEXICAL THIS!
LOGICAL!
#flydart #gdgac

27. Scalable Structure
Packages
Libraries
Functions
Mixins
Classes
Interfaces
#flydart #gdgac
library games;
!
import 'dart:math';
import 'players.dart';
!
class Darts {
/ ...
/
}
!
class Bowling {
/ ...
/
}
!
Player findOpponent(int skillLevel) {
/ ...
/
}

28. Too many Buttons
var button = new ButtonElement();
button.id = 'fancy';
button.text = 'Click Point';
button.classes.add('important');
button.onClick.listen((e) => addTopHat());
!
parentElement.children.add(button);
#flydart #gdgac

29. Method cascades
var button = new ButtonElement()
..id = 'fancy'
..text = 'Click Point'
..classes.add('important')
..onClick.listen((e) => addTopHat());
!
parentElement.children.add(button);
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30. Inline initialization
parentElement.children.add(
new ButtonElement()..text = 'Click Point');
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31. One of these things
is not like the other
Object
Persistable
Hug is not a is-a
Persistable
Hug
#flydart #gdgac
Don’t pollute your
inheritance tree!

32. Don’t inherit, mixin!
Object
Hug
#flydart #gdgac
Mixin
Persistable

33. Mixins
abstract class Persistable {
save() { ... }
load() { ... }
toJson();
}
!
class Hug extends Object with Persistable {
Map toJson() => {'strength':10};
}
!
main() {
var embrace = new Hug();
embrace.save();
}
#flydart #gdgac
Extend object & no
constructors? You can
be a mixin!
Apply the Mixin
Use Methods from
the Mixin

34. #flydart #gdgac

35. pub
•
A package manager
•
Integrated right from the start
•
670+ packages
#flydart #gdgac

36. Dart. Right now.
•
dart2js compiles Dart to JavaScript
•
at least until the DartVM is
available within all platforms
#flydart #gdgac

37. Ready to get started?
Write a Dart app!
(after a short break)
#flydart #gdgac

38. Codelab
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39. Codelab
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40. Hackathon
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41. Hackathon
Winners
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42. Please fill out the
evaluation form
#flydart #gdgac