Introduction to Dart

Introductory Tech Talk on Dart. Presented at the GDG Aachen Dart Flight School.

Based on the slides by Seth Ladd:
http://goo.gl/EbY4uS

Transcript

1. #flydart #gdgac Welcome
2. #flydart #gdgac
3. #flydart #gdgac Introduction to Based on the Slides by Seth Ladd
4. #flydart #gdgac Who am I? Sebastian Mauer GDG Aachen Co-Lead CS Student Software Engineer I don’t work for Google …yet aka
5. #flydart #gdgac
6. #flydart #gdgac ✔ Improved productivity ✔ Increased performance is about two things:
7. #flydart #gdgac Learn the language in under one hour. (we have the whole day)
8. #flydart #gdgac Use the tools you already know IntelliJ Sublime Eclipse (DartEditor)
9. #flydart #gdgac Compile to JavaScript (runs across the modern web)
10. #flydart #gdgac Run Dart on the server with the Dart VM
11. #flydart #gdgac require.js Backbone Backbone Marionette jQuery Modernizr moment.js dest templates PhantomJS Jasmine Docs Docs Docs Docs Docs Docs Docs Docs Docs
12. #flydart #gdgac Clear and consistent Unit test Dart SDK Polymer Intl Packages
13. #flydart #gdgac Apps start small, but grow and scale
14. #flydart #gdgac Simple syntax, ceremony free class Hug { Familiar
15. #flydart #gdgac Simple syntax, ceremony free class Hug { num strength; Hug(this.strength); Terse
16. #flydart #gdgac Simple syntax, ceremony free class Hug { num strength; Hug(this.strength); ! Hug operator +(Hug other) { return new Hug(strength + other.strength); } Operator overriding
17. #flydart #gdgac 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}) { // ... } Named, optional params w/ default value
18. #flydart #gdgac 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
19. #flydart #gdgac 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
20. #flydart #gdgac
21. #flydart #gdgac
22. #flydart #gdgac Clean semantics and behavior • Only true is truthy • There is no undefined, only null • No type coercion with ==, + Examples
23. #flydart #gdgac Clean semantics and behavior "hello".missing / / ?? Class 'String' has no instance getter 'missing'
 NoSuchMethodError : method not found: ‚missing'
 Receiver: "hello"
 Arguments: [] LOGICAL!
24. #flydart #gdgac Clean semantics and behavior 'hello' > 1 / / ?? Class 'String' has no instance method '>'. LOGICAL!
25. #flydart #gdgac Clean semantics and behavior var foo = 'top-level'; ! main() { if (true) { var foo = 'inside'; } ! print(foo); / / ?? What will this print? } LOGICAL! Variable scope? NO HOISTING! top-level
26. #flydart #gdgac Clean semantics and behavior class AwesomeButton { ! AwesomeButton(button) { button.onClick.listen((Event e) => this.atomicDinosaurRock()); } ! atomicDinosaurRock() { /* ... */ } } LOGICAL! Scope of „this“? LEXICAL THIS!
27. #flydart #gdgac Scalable Structure Functions Classes Libraries Packages Mixins Interfaces library games; ! import 'dart:math'; import 'players.dart'; ! class Darts { / / ... } ! class Bowling { / / ... } ! Player findOpponent(int skillLevel) { / / ... }
28. #flydart #gdgac 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);
29. #flydart #gdgac Method cascades var button = new ButtonElement() ..id = 'fancy' ..text = 'Click Point' ..classes.add('important') ..onClick.listen((e) => addTopHat()); ! parentElement.children.add(button);
30. #flydart #gdgac Inline initialization parentElement.children.add( new ButtonElement()..text = 'Click Point');
31. #flydart #gdgac One of these things is not like the other Object Persistable Hug Hug is not a is-a Persistable Don’t pollute your inheritance tree!
32. #flydart #gdgac Don’t inherit, mixin! Object Hug Mixin Persistable
33. #flydart #gdgac Mixins abstract class Persistable { save() { ... } load() { ... } toJson(); } ! class Hug extends Object with Persistable { Map toJson() => {'strength':10}; } ! main() { var embrace = new Hug(); embrace.save(); } Extend object & no constructors? You can be a mixin! Apply the Mixin Use Methods from the Mixin
34. #flydart #gdgac
35. #flydart #gdgac pub • A package manager • Integrated right from the start • 670+ packages
36. #flydart #gdgac Dart. Right now. • dart2js compiles Dart to JavaScript • at least until the DartVM is
 available within all platforms
37. #flydart #gdgac Ready to get started? Write a Dart app! (after a short break)
38. #flydart #gdgac Codelab
39. #flydart #gdgac Codelab
40. #flydart #gdgac Hackathon
41. #flydart #gdgac Hackathon Winners
42. #flydart #gdgac Please fill out the evaluation form