[weld-dev] Portable extension for injecting Seam beans

[Gavin King]

Folks, would someone please try out the following portable extension
for me. It should be enough to let you typesafe-inject a Seam2
component using Weld, e.g.

   @Inject @Qualifier MySeamComponent msc;

It's not enough to allow the use of typesafe injection in the seam
component itself, however.

Please test this for me, thanks!

++++
package org.seamframework;

import java.util.Collections;
import java.util.Set;

import javax.enterprise.context.RequestScoped;
import javax.enterprise.context.spi.CreationalContext;
import javax.enterprise.event.Observes;
import javax.enterprise.inject.spi.AnnotatedType;
import javax.enterprise.inject.spi.BeforeBeanDiscovery;
import javax.enterprise.inject.spi.Extension;
import javax.enterprise.inject.spi.InjectionPoint;
import javax.enterprise.inject.spi.InjectionTarget;
import javax.enterprise.inject.spi.ProcessInjectionTarget;
import javax.enterprise.util.AnnotationLiteral;

import org.jboss.seam.Component;
import org.jboss.seam.annotations.Name;

public class SeamComponentExtension implements Extension {
	
	void beforeBeanDiscovery(@Observes BeforeBeanDiscovery bbd) {
		bbd.addStereotype(Name.class, new AnnotationLiteral<RequestScoped>()
{}); //TODO: put it in a @StatelessScope!
	}
	
	<X> void processInjectionTarget(@Observes final
ProcessInjectionTarget<X> pit) {
		final AnnotatedType<X> at = pit.getAnnotatedType();
		if ( at.isAnnotationPresent(Name.class) ) {
			if ( !pit.getInjectionTarget().getInjectionPoints().isEmpty() ) {
				throw new RuntimeException("CDI injection points not supported for
Seam2 components");
			}
			InjectionTarget<X> it = new InjectionTarget<X>() {
				@Override
				public void inject(X instance, CreationalContext<X> ctx) {
					//TODO figure out a way to inject into the Seam component
				}
				@Override
				public void postConstruct(X instance) {}
				@Override
				public void preDestroy(X instance) {}
				@Override
				public void dispose(X instance) {}
				@Override
				public Set<InjectionPoint> getInjectionPoints() {
					return Collections.EMPTY_SET;
				}
				@Override
				public X produce(CreationalContext<X> ctx) {
					//TODO: it would be better to override
Component.instantiateJavaBean() to call
					//      it.produce(), in order to get injection, etc, but then we
would have
					//      to figure out a way to replace the Seam Component object
					return (X) Component.getInstance( at.getJavaClass(), true );
				}
			};
			pit.setInjectionTarget(it);
		}
	}
	
}


-- 
Gavin King
gavin.king at gmail.com
http://in.relation.to/Bloggers/Gavin
http://hibernate.org
http://seamframework.org