This slides show the limitations of the existing scopes and how to solve them with the scopes provided by MyFaces CODI.

1. MyFaces CODI Scopes
Use the right scopes for your CDI beans

2. Agenda
• The History
• CODI in a Nutshell
• CODI Setup
• CODI Scopes in Action
• Coding
• CODI Conversation - Insights
• Your Use-Cases

3. THE HISTORY

4. Scopes of the Servlet Spec
Application
Session
Custom Scopes
Request

5. CODI Scope Overview
Application
Session
Window
Conversation
View-Access
Request

6. Why custom Scopes?
• Request scope too short for most UI-Use-Cases
• Session scope
– Too long
– No support for multi-window applications
• Different (conversation) concepts available
– MyFaces Orchestra
– CDI Conversation Scope
– MyFaces CODI Scopes
• Conversation Scope
• View-Access Scope
• Window Scope

7. MyFaces Orchestra
• CODI is NOT Orchestra.NEXT
• Orchestra is for Spring (only)
• CODI is for CDI (only)
• Orchestra introduced great concepts!
 CODI was planned as "type-safe Orchestra" for CDI
Now it’s way more (in most areas) but
without Persistence-Management!

8. What‘s about @ConversationScoped of CDI?
• Completely broken for several use-cases!
• More like inflexible sessions per window
• Some of the disadvantages
– Overhead e.g. with failed conversion/validation
– Lazy termination (after the rendering process)
– Restarting conversations during a request isn’t possible
– End the whole conversation or nothing
– An explicit start is required
– Manual check if conversation has been started
• Test them with your use-cases!
 use them or forget them 

9. MyFaces CODI - Overview
• MyFaces Extensions CDI aka MyFaces CODI is a
portable CDI extension which can be used with
Apache OpenWebBeans, JBoss Weld,… and
in combination with other portable CDI extensions
• CODI-Core is required in any case
• Modules
– JSF Module (for 1.2 and 2.0 and 2.1)
– JPA Module
– BV Module
– I18n-Message Module
– Scripting Module
– Test Support Modules

10. MyFaces CODI in a Nutshell
• JSF 1.2 and 2.x • Type-safe View-Configs
• Type-safety • Type-safe Navigation
• Extensibility • JPA Integration
• Advanced Scopes • Dependency Injection
• Various Events Support for BV
• View-Controller • Advanced I18n
• JSF 2 Scope Mappings • Scripting Integration
• And more!

11. CODI - SETUP

12. Getting CODI up and running
• Add CODI to the project
– With Maven
• Add the modules (or the all-in-one package) to the POM
– Without Maven
• Download the current dist package
• Add the modules (or the all-in-one package) to the Classpath of
the project
• Start using it!
Hint:
mvn archetype:generate -DarchetypeCatalog=http://myfaces.apache.org

13. Getting CODI up and running - Hints
• With JEE 5 and Mojarra use the controlled bootstrapping
add-on
• Attention (hint for all bean archives):
Ensure that the libs aren’t duplicated – otherwise the CDI
implementation will blame ambiguous interceptors, beans,…

14. CODI SCOPES IN ACTION

15. CODI Scopes (with OWB) - Performance

16. Request Scope (as a Comparison) - Details - 2

17. Request Scope (as a Comparison) - Details - 1

18. Window-Scope
• Like an advanced session per Browser-Window/Tab
• Use it e.g. instead of @SessionScoped
• Starts automatically with the first access
• No support for (CODI conversation-)groups
• Example:
@WindowScoped
public class PreferencesBean
implements Serializable {
//...
}

19. View-Access Scope
• The next page does not use a view-scoped bean
 the bean get un-scoped
• Simple alternative to @ConversationScoped (of CODI)
• Starts automatically with the first access
• No support for (CODI conversation-) groups
• Example
@ViewAccessScoped
public class RegistrationWizard
implements Serializable {
//...
}

20. (Grouped) Conversations
• Every bean is isolated in a separated conversation
• The bean class is the implicit group
• Terminating a conversation un-scopes all beans connected
with the conversation (per default 1) immediately
• Termination manually via API or automatically via timeout
• Starts automatically with the first access
• Example
@ConversationScoped
public class OrderWizard
implements Serializable {
//...
}

21. Grouped Conversations - 1
• Grouping beans which belong to a logical conversation
(e.g. a Use-Case) can be grouped together
• One bean can be used for multiple (parallel) use-cases
• @ConversationGroup is a "special" CDI qualifier
• Termination of the group  un-scoping of all bean(s)
• Example 1
@ConversationScoped
@ConversationGroup(OrderUseCase.class)
public class Customer implements Serializable {
//...
}

22. Grouped Conversations - 2
@Produces
@ConversationScoped
@ConversationGroup(UseCase1.class)
public DemoBean createDemoBeanForUseCase1() {
return new DemoBean("createDemoBeanForUseCase1");
}
@Produces
@ConversationScoped
@ConversationGroup(UseCase2.class)
public DemoBean createDemoBeanForUseCase2() {
return new DemoBean("createDemoBeanForUseCase2");
}

23. Closing vs. Restarting Conversations - 1
• Conversation#close
Closes a conversation immediately
• Conversation#restart
Un-scopes all beans of the conversation but internal
data-structures are intact for using it again
(better performance)
• Example
@Inject
private Conversation conversation;
//...
this.conversation.close();

24. @CloseConversationGroup
• @CloseConversationGroup
Interceptor for closing a conversation group e.g.
after a method-invocation or based on a given exception.
• Examples:
@CloseConversationGroup
public void registerUser () {}
@CloseConversationGroup(group = UseCase1.class)
public void registerUser () {}
@CloseConversationGroup(
group = UseCase1.class, on = MyException.class)
public void registerUser () {}

25. CODI CONVERSATION - INSIGHTS

26. Optional Configuration
• CodiConfig
– WindowContextConfig
• getWindowContextTimeoutInMinutes
• isUnknownWindowIdsAllowed
• getMaxWindowContextCount
• isCloseEmptyWindowContextsEnabled
• is*EventEnabled
• …
– ConversationConfig
• getConversationTimeoutInMinutes
• is*EventEnabled
• …
– …

27. WindowScoped vs WindowContext
• The Window-Context represents the whole window including
all scopes which are bound to it
• Window-scoped beans are just a part of the current window
• WindowContext API allows to manage the current window
• Example
@Inject
private WindowContext windowContext;
//...
this.windowContext.getId();
this.windowContext.closeConversations();

28. Window-Context
Window(-Context)
API and SPI
[Scope] [Scope] [Scope] [Scope] [Scope]
Window Conversation Conversation View- View-
Group: Group: Access Access
Bean1 UseCase1
Bean 3
Bean 4
Bean 1
Bean 2
Bean 1
Bean 1
Bean 2
Attributes

29. Powerful SPI
• WindowContextManagerFactory
• WindowContextFactory
• WindowContextQuotaHandler
• WindowHandler
• ConversationFactory
• WindowContextManager
• BeanEntryFactory
• …

30. Optional Events
• WindowContextEvent
– CreateWindowContextEvent
– CloseWindowContextEvent
• ConversationEvent
– StartConversationEvent
– RestartConversationEvent
– CloseConversationEvent
• BeanEvent
– ScopeBeanEvent
– AccessBeanEvent
– UnscopeBeanEvent

31. TELL US YOUR USE-CASES!

32. Links
• http://myfaces.apache.org/extensions/cdi/
• https://cwiki.apache.org/confluence/display/EXTCDI/Index
• https://svn.apache.org/repos/asf/myfaces/extensions/cdi/
• http://twitter.com/MyFacesTeam
• http://myfaces.apache.org/extensions/cdi/mail-lists.html
• Recommended
– http://openwebbeans.apache.org
– http://code.google.com/a/apache-extras.org/p/
myfaces-codi-addons/
– http://os890.spaaze.com/myfaces-codi