This document discusses the integration between Errai and CDI. It covers use cases like declaring CDI components as services, exposing CDI components as RPC endpoints, and integrating with the CDI event subsystem. The bootstrap process and invocation handling are explained. The status of the Errai-CDI integration project is outlined and the roadmap includes further work on bean scopes, integration with EJB3, and context propagation for transactions and security.

1. Errai-CDI Integration
Heiko Braun <hbraun@redhat.com>
Apr 2010

2. Topics
• Use cases
• CDI Concepts
• Bootstrap process
• Invocation Handling
• Status & Roadmap
2

3. Use cases
• Initially
• Declaring a CDI component as Service
• Exposing a CDI component as RPC endpoint
• Integrating with the CDI event subsystem
3

4. Declaring Services
GWT Client
• Most low level use cases
• Similar to MessageDriven
Bean
• Service implementation CDI Component
fully managed by CDI
container
4

5. Exposing RPC endpoints
GWT Client
• Exposes a typed
interface
• Similar to EJB Session
beans
CDI Component
Remote interface
5

6. Working with CDI events
• Bi-directional event GWT Client
exchange
• Discriminate on:
- Event Type
- Qualifier
Annotations
• Exposes high level
CDI Component
CDI client API
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7. CDI Concepts
• Portable Extensions
• Integration point when container bootstraps
• Create beans, annotation processing, meta data
modifications
• Scope & Lifecycle
• ApplicationScoped, RequestScoped, ConversationScoped
• Bean context & reference
• Lookup and instance (reference) creation
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8. Bootstrap process
• Two phases: CDI -> Errai Bootstrap
• Ordering important
• CDI Service discovery first
• Services instances are maintained by CDI
8

9. Service discovery
• Provide injection points
for Errai Components
• Discover Errai
annotations during CDI
bootstrap
• Provide service proxies
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10. Invocation Handling
• Encapsulated in
invocation proxy
• Lookup bean
reference
(instance)
• Context & Scope
managed by CDI
10

11. Invocation proxies
Bean invocation (RPC)
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12. Event dispatcher
CDI Observer
12

13. Event client boilerplate
GWT Client
13

14. Status
• Project:
http://anonsvn.jboss.org/repos/errai/projects/
weld-integration/trunk
• Basic use cases covered
• Incorporate feedback from the CDI team
• Clarification on Errai RPC API
14

15. Roadmap
• More work on Bean scopes:
• Session-, Request-, ConversationScoped
• Integration with EJB3
• Stateless, Stateful session beans
• Transactions, Security, etc:
• Context propagation
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