Dart: The Dawn of Web Apps

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Dart: The Dawn of Web Apps ladicek.github.com

500 000 lines of JS

500 000 lines of JS Say hello to Dart!

main() { print("Hello, Dart!"); }

class Person { var name, age; Person(this.name, this.age); toString() =>
"$name ($age years)"; } main() { var me = new Person("Ladislav Thon", 30); print(me); }

Optional typing void main() { Person me = new Person("Ladislav
Thon", 30); List<Person> people = [me, ...]; people.forEach((Person person) => print(person)); people.forEach((person) { // iterable print(person); }); people.forEach(print); // closurization }

Innocent until proven guilty

Client-side code import 'dart:html'; main() { query('#button').onClick.listen((event) { // stream
... }); }

Server-side code import 'dart:io'; main() { HttpServer.bind('127.0.0.1', 1337).then((server) { //
future server.listen((request) { // stream … }); }); }

Isolates import 'dart:isolate'; main() { var box = new MessageBox();
streamSpawnFunction(worker).add( { 'replyTo': box.sink, 'value': ... } ); // sink box.stream.listen((response) { ... }); // stream } worker() { stream.listen((message) { ... }); }

Mirrors import 'dart:mirrors'; main() { var person = new Person(...);
var personMirror = reflect(person); personMirror.getField('name').then((resultMirror) { print(resultMirror.reflectee); }); // async today, probably sync in the future }

And a lot more

Implicit interfaces & properties abstract class Person { get name;
get age; set age(value); } class Monster implements Person { final name = 'Cthulhu'; var age = '?!?!?!'; }

Inheritance & mixins class Entity { int id; } //
or whatever abstract class Named { get name; toString() => '$name'; } class Person extends Entity with Named { get name => 'Cthulhu'; }

Optional parameters class Person { var name, age; Person({this.name: '<unknown>',
this.age: 0}); growOlder([years = 1]) { age += years; } } main() { var me = new Person(name: 'Ladislav Thon'); me.growOlder(30); }

Constructors class Person { final name, age; Person(this.name, this.age); Person.me()
: name = 'Ladislav Thon', age = 30; static Person cache; factory Person.cachedMe() { if (cache == null) { cache = new Person.me(); } return cache; } }

Cascades class Person { var name, age; } main() {
var me = new Person() ..name = 'Ladislav Thon' ..age = 30; }

Privacy class Person { var _isEnemy; var name, age; }
main() { // in another library var me = ...; print(me._isEnemy); // NO! }

class Proxy { var target; Proxy(this.target); noSuchMethod(invocation) { print('Calling ${invocation.memberName}');
return invocation.invokeOn(target); } }

Web UI

Web UI Web Components

Web UI MDV Templates

Web UI Polyfill for current browsers

HTML part <element name="x-counter" constructor="Counter" extends="div"> <template> <span>{{value}}</span> <button on-click="increment()">+1</button>
</template> <script type="application/dart">...</script> </element>

Dart part import 'package:web_ui/web_ui.dart'; class Counter extends WebComponent { int
value = 0; increment() { value++; } }

Usage <html> <head> <link rel="components" href="counter.html"> </head> <body> <x-counter></x-counter> <script
type="application/dart">main() {}</script> </body> </html>

Conditions & iteration <table template if="rows != null && !rows.isEmpty">
<tr template iterate="headerItem in header"> <th>{{headerItem}}</th> </tr> <tbody template iterate="row in rows"> <tr template iterate="item in row"> <td>{{item}}</td> </tr> </tbody> </table>

Passing values <html> <head> <link rel="components" href="grid.html"> </head> <body> <x-grid
header="{{header}}" rows="{{rows}}"> </x-grid> <script type="application/dart">...</script> </body> </html>

Performance Fast startup

Performance Fast runtime (beats V8 already)

Tooling Eclipse, IntelliJ IDEA vim, Sublime Text

So what is it all about?

So what is it all about? Structure!

www.dartlang.org

ladicek.github.com ?

Dart: The Dawn of Web Apps

Dart: The Dawn of Web Apps

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