An introduction to the features coming in Robotlegs 2.0 and a discussion of covariance

2. robotlegs

3. robotlegs 2.0

5. the goals

6. configurable
because every project is unique

7. versatile
rigidity sucks

8. concise
use only what you need

9. fluent
make(tea).with(milk).butNot(sugar)

11. govt health warning
these examples are subject to change

13. the features

15. .context builder

16. Contexts in robotlegs circa v1

17. Contexts in robotlegs circa v1
public class Context
{
protected var _injector:IInjector;
protected var _reflector:IReflector;
protected var _contextView:DisplayObjectContainer;
protected var _commandMap:ICommandMap;
protected var _mediatorMap:IMediatorMap;
protected var _viewMap:IViewMap;
}

19. public class Container
{
private var youCantSeeMe:SoLetsHopeIKnowWhatImDoing;
protected var sureYouCanOverrideMe:ButYouAintGettingRidOfMe;
}

20. public class Container
{
private var youCantSeeMe:SoLetsHopeIKnowWhatImDoing;
protected var sureYouCanOverrideMe:ButYouAintGettingRidOfMe;
}
in version one,
features were bound to the context.

21. RL2 contexts are created with what you need
not extended with what you don’t

22. Introducing the context builder

23. Introducing the context builder
public interface IContextBuilder
{
build():IContext;
withBundle(bundle:IContextBuilderBundle):IContextBuilder;
withConfig(config:IContextConfig):IContextBuilder;
withContextView(value:DisplayObjectContainer):IContextBuilder;
withDispatcher(value:IEventDispatcher):IContextBuilder;
withExtension(extension:IContextExtension):IContextBuilder;
withInjector(value:Injector):IContextBuilder;
withParent(value:IContext):IContextBuilder;
withProcessor(processor:IContextProcessor):IContextBuilder;
}

24. .withConfig

25. .withConfig
public interface IContextConfig
{
function configure(context:IContext):void;
}
setup your configuration to execute once at build.

26. .withExtension

27. .withExtension
public interface IContextExtension
{
function initialize(context:IContext):void;
function install(context:IContext):void;
function uninstall(context:IContext):void;
}
extensions add functionality at any time.

28. .withProcessor

29. .withProcessor
public interface IContextProcessor
{
function process(context:IContext, callback:Function):void;
}
processors asynchronously affect the build state.

31. .pre-configured bundles

32. four tasty flavours of robotlegs
each representing a context builder bundle

34. Original
»
when plain old vanilla is just right.

36. light
» when size and performance are paramount.

38. rapid
»
when time is of the essence.

40. »
smart
views
when you simply can’t live without view injection.

42. .type matching

43. Definion

44. Definion
public class TypeMatcher
{
function anyOf(... params):TypeMatcher;
function noneOf(... params):TypeMatcher;
function allOf(... params):TypeMatcher;
}
Usage
new TypeMatcher()
.allOf(ISpaceShip, IEnemy)
.noneOf(DeathStar)
flexible and fluent type matching syntax

46. .view management

48. viewManager.addContainer(contextView);
viewManager.addHandler(mediatorMap);
viewManager.addWatcher(stageWatcher);
viewManager.addContainer(myPopUp);
wire view handlers to view watchers

49. viewManager.addContainer(contextView);
viewManager.addHandler(mediatorMap);
viewManager.addWatcher(stageWatcher);
viewManager.addContainer(myPopUp);
wire view handlers to view watchers
viewManager.addContainer(myPopUp);
viewManager.addContainer(myAIRWindow);
native support for flex popups and air windows.

51. .mediate anything

53. mediatorMap.map(UserDetailsMediator).toView(IUserDetailsAware);
map mediators to interfaces rather than
concrete classes.

54. mediatorMap.map(UserDetailsMediator).toView(IUserDetailsAware);
map mediators to interfaces rather than
concrete classes.
mediatorMap
.map(SomeMenuMediator)
.toMatcher()
.anyOf(TopLevelMenu, AdminMenu, FootMenu);
use type-matching to refine your mapping

56. .guards and hooks

57. possible use-cases for a guard:

58. possible use-cases for a guard:
• prevent mediation when ...

59. possible use-cases for a guard:
• prevent mediation when ...
• prevent command execution when ...

60. possible use-cases for a guard:
• prevent mediation when ...
• prevent command execution when ...
mediatorMap
.map(UserDetailsMediator)
.toView(IUserDetailsAware)
.withGuard(UserIsAdminGuard);
a guard represents conditional logic for an
action to occur.

61. scenarios for using a hook:

62. scenarios for using a hook:
• customised logging

63. scenarios for using a hook:
• customised logging
• view skinning

64. scenarios for using a hook:
• customised logging
• view skinning
• view localisation

65. scenarios for using a hook:
• customised logging
• view skinning
• view localisation
• instance configuration prior to command execution

66. scenarios for using a hook:
• customised logging
• view skinning
• view localisation
• instance configuration prior to command execution
commandMap
.map(UserLoginCommand)
.toEvent(UserLoginEvent.LOGIN, UserLoginEvent)
.withHook(ConfigureUserDetails)

67. scenarios for using a hook:
• customised logging
• view skinning
• view localisation
• instance configuration prior to command execution
commandMap
.map(UserLoginCommand)
.toEvent(UserLoginEvent.LOGIN, UserLoginEvent)
.withHook(ConfigureUserDetails)
a hook enables pre-processing on an action.

69. .rule sets and command flow

70. possible uses of a rule:

71. possible uses of a rule:
• adding or removing mediators

72. possible uses of a rule:
• adding or removing mediators
• loading or unloading commands

73. possible uses of a rule:
• adding or removing mediators
• loading or unloading commands
a rule can prevent or ensure an action’s occurrence.

74. command flows:

75. command flows:
create a workflow of commands to represent a
complex sequence

76. command flows:
create a workflow of commands to represent a
complex sequence
flows are pathways between commands

78. .swift-suspenders integration

80. //creates a new instance per injection
injector.map(SomeType); //or injector.map(SomeType, ‘named’);
//create new instance per injection and map to
injector.map(IService).toType(SomeService); //or value .toValue(someInstance)
//map as singleton instance
injector.map(SomeService).asSingleton(); //or .toSingleton(SomeService);
//allows to easily specify custom providers to use for a mapping
injector.map(IService).toProvider(new CustomProvider());
//prevents sharing the mapping with child injectors;
injector.map(SomeService).local(); // .shared() reverts it
//allow child injector to map if none exists
injector.map(SomeService).soft(); // .strong() maps regardless
//prevents changes to the mapping; returns a unique key object
injector.map(SomeService).seal(); //can revert with key and .unseal()
full integration with swift suspenders 2
leverages the entire toolkit.

82. .module integration

83. integrated module automation:

84. integrated module automation:
• context wired up by parent once added to stage

85. integrated module automation:
• context wired up by parent once added to stage
• view events are collated in the one view manager

86. integrated module automation:
• context wired up by parent once added to stage
• view events are collated in the one view manager
• child injectors created and wired to the parent

87. integrated module automation:
• context wired up by parent once added to stage
• view events are collated in the one view manager
• child injectors created and wired to the parent
• default injections to ensure modules work both
standalone and when integrated.

88. integrated module automation:
• context wired up by parent once added to stage
• view events are collated in the one view manager
• child injectors created and wired to the parent
• default injections to ensure modules work both
standalone and when integrated.
in robotlegs 2, modules just work.

90. .robotlegs inspector

91. new inspector
gadget tool to
help you with
your
robotlegging.
info here.

93. an example in covariance
mediate behaviours not views

94. for comparison

95. for comparison
let’s look at a simple robotlegs v1 application

96. invariant mediation (via classes)

97. invariant mediation (via classes)
View

98. invariant mediation (via classes)
View
Mediator

99. invariant mediation (via classes)
View
Mediator

100. invariant mediation (via classes)
events
View
Mediator

101. invariant mediation (via classes)
events
View
Mediator
one mediator per view.

102. what’s wrong with this approach?

103. what’s wrong with this approach?
• the mediator is tightly coupled to the view

104. what’s wrong with this approach?
• the mediator is tightly coupled to the view
• view is restricted to one mediator

105. what’s wrong with this approach?
• the mediator is tightly coupled to the view
• view is restricted to one mediator
• no reuse of mediation

106. how to fix this in v1?

107. how to fix this in v1?
using the variance utility

108. covariant mediation (via interfaces)

109. covariant mediation (via interfaces)
View

110. covariant mediation (via interfaces)
View
IBehaviour A
IBehaviour B
IBehaviour C

111. covariant mediation (via interfaces)
View
Mediator A
IBehaviour A
IBehaviour B
IBehaviour C Mediator B
Mediator C

112. covariant mediation (via interfaces)
View
Mediator A
IBehaviour A
IBehaviour B
IBehaviour C Mediator B
Mediator C

113. covariant mediation (via interfaces)
e v e n t s
View
Mediator A
e v e n t s
IBehaviour A
IBehaviour B
e v e n t s
IBehaviour C Mediator B
Mediator C

114. covariant mediation (via interfaces)
e v e n t s
View
Mediator A
e v e n t s
IBehaviour A
IBehaviour B
e v e n t s
IBehaviour C Mediator B
Mediator C
n mediators per view.

115. what is wrong with this contract?

116. what is wrong with this contract?
import flash.events.IEventDispatcher;
[Event(name="doAsync", type="...ControlEvent")]
public interface IServiceStarter extends IEventDispatcher
{
function serviceReturned():void;
}
we have to extend IEventDispatcher and there’s no
enforcement of contract.

118. .enter signals, stage right

119. with signals, we define the contract

120. with signals, we define the contract
import org.osflash.signals.ISignal;
public interface IServiceStarter
{
function serviceReturned():void;
function get start():ISignal;
}
and force the view to comply
import org.osflash.signals.ISignal;
private var startSignal:ISignal = new Signal();
public function serviceReturned():void
{
Alert.show("The service returned.","Guess what?");
}
public function get start():ISignal { return startSignal; }
...
<s:Button label=”Start” click=”start.dispatch” />

121. with covariance and signals

122. with covariance and signals
View
IBehaviour A
IBehaviour B
IBehaviour C

123. with covariance and signals
View
Mediator A
IBehaviour A
IBehaviour B
IBehaviour C Mediator B
Mediator C

124. with covariance and signals
View
Mediator A
IBehaviour A
IBehaviour B
IBehaviour C Mediator B
Mediator C

125. with covariance and signals
View
Mediator A
IBehaviour A
IBehaviour B
IBehaviour C Mediator B
Mediator C
each view is mediated bidirectionally.

126. to view this sample online
go to j.mp/covariance
Libraries used:
• robotlegs 1.5.2
• robotlegs variance utility 1.1
• as3-signals 0.9-beta

128. so when is robotlegs 2
coming?

130. ...now.

132. as of this afternoon
robotlegs 2 is in open beta.

133. Stay updated.

134. Stay updated.
Add you name to the RL2 beta list by commenting on:
j.mp/robotlegs2
Join the robotlegs google group
Follow @robotlegs_as3 on Twitter.

136. fin.
about.me/justinj
@justinjmoses