This document discusses using Google Web Toolkit (GWT) with Context and Dependency Injection (CDI). It covers use cases like invoking CDI beans from GWT clients, exposing domain models to GWT, and requirements like seamless integration and reduction of boilerplate. Key concepts discussed include beans, qualifiers, scopes, and how CDI fits into the build and runtime. Examples demonstrate conversation scoped beans and how clients can manage conversations. The document also mentions related technologies and that the Errai project uses the Weld implementation of CDI.

1. GWT & CDI
Heiko Braun <hbraun@redhat.com>

2. Topics
• CDI & GWT
• Use Cases & Requirements
• Relevant Concepts
• Likeminded Technologies
• Demo

3. GWT & CDI

4. Google Web Toolkit
• Create Ajax applications from Java sources
• GWT SDK: Compiler, API, Tools
• Creates highly optimized, portable javascript
code

5. Context and
Dependency Injection
• CDI: JSR-299, JSR-330
• Reference implementation: Weld
• Seam 3
• EE6 component model
• Portable extensions
• shrink-size or extend runtime
(framework)

6. Use Cases &
Requirements

7. Use Cases
• Invoke CDI beans from GWT clients
• RPC
• Pub/Sub
• Eventing
• Expose domain models to GWT clients
• Serialization

8. Example: RPC bean

9. Example: RPC Client

10. Requirements
• “Seamless integration”
• Verified concepts
• Concise programming model
• Reduction of boilerplate

11. Example: Event Bean

12. Example: Event Client

13. Relevant Concepts

14. Beans, Qualifiers &
Scopes
• Bean type: Client-visible type (class, interface)
• Qualifier: Distinguish multiple beans of the same
type
• @Named, @Asynchronous
• Scope: Determines instance lifecycle
• @SessionScoped,
@ConversationScoped, @RequestScoped

15. Build & Run-time
• Run-time • Build-time
• Deployment
• Same Origin Policy?
• GWT Compiler constraints
• Transactions, Security • Domain model & API?
• Context propagation?
• Clustering, Failover
• Hosted Mode
• Stateful Ajax Client? • CDI Bootstrap?
• Deferred Binding
• Boiler plate
Java Javascript

16. Example: Conversation
Scoped Bean

17. Example: Client managed
conversation (1)

18. Example: Client managed
conversation (2)

19. Likeminded
Technologies

20. Related Technologies
• JPA
• Serialization
• Detachment (lazy/eager loading)
• Merging
• DataBinding
• Widgets, Validation, Synchronization
• JMS
• Ajax client as Topic Subscriber/Publisher

21. Project and
Roadmap

22. Errai & Weld
• Errai acts as Umbrella (http://jboss.org/errai)
• Weld as Reference implementation
• Driven by both Errai and CDI Team
• Same runtimes Weld supports:
• SE, Servlet, EE6, EC2:
“Start POC, grow big”

23. Questions?
• Project: http://jboss.org/errai
• Weld: http://seamframework.org
• Blog: http://errai-blog.blogspot.com/
• IRC: irc.freenode.net#errai