A basic introduction about the tools of robotlegs and swiftsuspenders to create a basic Robotlegs project.

1. Robotlegs Workshop
29 january 2011
Eric-Paul Lecluse & Erik van Nieuwburg
Monday, January 31, 2011

2. What is Robotlegs?
• MVC framework
• Looks a lot like pureMVC
• Focused on wiring application tiers
• Lightweight / small footprint
• Based on ‘dependency injection’ via
SwiftSuspenders library
Monday, January 31, 2011

3. Dependency Injection?
• It’s the act of supplying objects with their
required data.
• Passing an argument to a constructor is an
example of dependency injection.
• Less boilerplate code
• Flexible adding of alternative
implementations of a given service.
Monday, January 31, 2011

4. Robotlegs + Dependency Injection
• Based on SwiftSuspenders (metadata driven
Inversion Of Control solution for AS3)
• Evolves around 2 meta tags: [Inject] and
[PostConstruct]
• If you don’t use the supplied SWC files ,
add these parameters to MXMLC:
• -keep-as3-metadata+=Inject
• -keep-as3-metadata+=PostConstruct
Monday, January 31, 2011

5. So what does a class look like?
package com.rumblingskies.view
{
import com.rumblingskies.model.ScoreModel;
import org.robotlegs.mvcs.Mediator;
public class BallMediator extends Mediator
{
[Inject]
public var scoreModel:ScoreModel;
override public function onRegister() : void
{
}
}
}
Monday, January 31, 2011

6. But how to inject?
Typically, during startup of your app, you define
injector rules. You can do that in 4 ways:
injector.mapValue(MyClass, myClassInstance);
injector.mapClass(MyClass, MyClass);
injector.mapSingleton(MyClass);
injector.mapSingletonOf(IMyClass, MyClass);
Monday, January 31, 2011

7. injector.mapValue
(MyClass, myClassInstance);
When asked for
a specific class,
use this specific instance of the class
for injection.
Monday, January 31, 2011

8. injector.mapClass
(MyClass, MyClass);
When asked for
a specific class,
create and inject a new instance
of that class.
Monday, January 31, 2011

9. injector.mapSingleton(MyClass);
When asked for
a specific class,
always provide the same instance
of that class.
No more writing Singleton logic :-)
This is a managed single instance, enforced by the
framework, and not a Singleton enforced within the
class itself.
Monday, January 31, 2011

10. injector.mapSingletonOf
(IMyClass, MyClass);
When asked for
a specific class,
always provide the same instance
of the implementation that class.
No more writing Singleton logic :-)
This is a managed single instance, enforced by the
framework, and not a Singleton enforced within the
class itself.
Monday, January 31, 2011

11. Robotlegs Architecture
Built up in 4 tiers:
•Model
•View
•Controller
•Services
Services are models, but for communication with
the outside world. For instance loading an image
from Flickr.
Monday, January 31, 2011

12. Model
Contains / maintains your application’s data /
state
Extends ‘Actor’ class so it can dispatch events
Dumb objects: receive value changes and then
dispatch events. That’s it.
Monday, January 31, 2011

13. public class ScoreModel extends Actor
{
private var _score:Number;
public function ScoreModel()
{
}
public function get score() : Number
{
return _score;
}
public function set score(score : Number) : void
{
_score = score;
dispatch(new ScoreEvent(ScoreEvent.UPDATE));
}
}
Monday, January 31, 2011

14. Model Instantiation
Typically, you inject Model instances.
So during system startup, define injector rules for
injection of Models:
injector.mapSingleton(ScoreModel);
This way your ScoreModel class is behaving as a
Singleton.
Monday, January 31, 2011

15. View
The visual elements of your app
To interact with the framework they have a
seperate Mediator class
Mediators listen to
• events travelling through the framework
• events sent by their view component
Monday, January 31, 2011

16. View instantiation
Again, during system startup you typically tell the
framework which views and mediators work
together.
mediatorMap.mapView( viewClass, mediatorClass, injectViewAs,
autoCreate, autoRemove );
By default, mediators are auto-created when a
view is ADDED_TO_STAGE!
It’s fully automated! Yeah.....i know.....it rocks :-)
Monday, January 31, 2011

17. public class Ball extends Sprite
{
public function Ball()
{
redraw();
}
public function redraw() : void
{
graphics.clear();
graphics.beginFill(0xffffff *
Math.random());
graphics.drawCircle(0, 0, 25);
}
}
Monday, January 31, 2011

18. public class BallMediator extends Mediator
{
[Inject]
public var ballView : Ball;
[Inject]
public var stats:StatsModel;
override public function onRegister() : void
{
addViewListener(MouseEvent.CLICK, handleViewClick);
addContextListener(HelloRobotLegsEvent.BALL_CLICKED,
handleBallClicked);
}
private function handleViewClick(e : MouseEvent) : void
{
stats.recordBallClick();
dispatch(new HelloRobotLegsEvent
(HelloRobotLegsEvent.BALL_CLICKED));
}
private function handleBallClicked(e : HelloRobotLegsEvent) : void
{
ballView.redraw();
}
}
Monday, January 31, 2011

19. Commands
Are similar to pureMVC commands.
Run an execute() method
At system startup, map your Commands to
framework Events like this:
commandMap.mapEvent(MyAppDataEvent.DATA_WAS_RECEIVED,
MyCoolCommand, MyAppDataEvent);
Robotlegs natively does not have a
MacroCommand like pureMVC.
Monday, January 31, 2011

20. public class CreateBallCommand extends Command
{
[Inject]
public var event:HelloRobotLegsEvent;
override public function execute() : void
{
var ball : Ball = new Ball(event.ballName);
ball.x = Math.random() * 500;
ball.y = Math.random() * 400;
contextView.addChildAt(ball, 0);
}
}
Monday, January 31, 2011

21. Quickstart Help
Download ZIP file here:
www.rumblingskies.com/files/robotlegs-workshop/pong.zip
1) Subclass Context class and overwrite the startup() method
2) Configure the injector
3) fill mediatorMap
4) fill commandMap
5) add children to contextView
6) start writing logic in Model, Mediator,View and Command
classes.
Monday, January 31, 2011