/*
* Copyright 2009 JBoss, a divison Red Hat, Inc
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.jboss.errai.enterprise.rebind;
import java.lang.annotation.Annotation;
import java.util.Set;
import javax.enterprise.event.Observes;
import javax.enterprise.util.TypeLiteral;
import org.jboss.errai.bus.client.api.Message;
import org.jboss.errai.bus.client.api.annotations.Local;
import org.jboss.errai.bus.client.framework.MessageBus;
import org.jboss.errai.enterprise.client.cdi.AbstractCDIEventCallback;
import org.jboss.errai.enterprise.client.cdi.CDIProtocol;
import org.jboss.errai.enterprise.client.cdi.api.CDI;
import org.jboss.errai.ioc.client.api.CodeDecorator;
import org.jboss.errai.ioc.rebind.ioc.IOCDecoratorExtension;
import org.jboss.errai.ioc.rebind.ioc.InjectUtil;
import org.jboss.errai.ioc.rebind.ioc.InjectableInstance;
import org.jboss.errai.ioc.rebind.ioc.codegen.Context;
import org.jboss.errai.ioc.rebind.ioc.codegen.Parameter;
import org.jboss.errai.ioc.rebind.ioc.codegen.Statement;
import org.jboss.errai.ioc.rebind.ioc.codegen.builder.BlockBuilder;
import org.jboss.errai.ioc.rebind.ioc.codegen.builder.impl.AnonymousClassStructureBuilderImpl;
import org.jboss.errai.ioc.rebind.ioc.codegen.meta.MetaMethod;
import org.jboss.errai.ioc.rebind.ioc.codegen.meta.MetaParameter;
import org.jboss.errai.ioc.rebind.ioc.codegen.util.Bool;
import org.jboss.errai.ioc.rebind.ioc.codegen.util.Refs;
import org.jboss.errai.ioc.rebind.ioc.codegen.util.Stmt;
/**
* Generates the boiler plate for @Observes annotations use in GWT clients.<br/>
* Basically creates a subscription for a CDI event type that invokes on the annotated method.
*
* @author Heiko Braun <hbraun@redhat.com>
* @author Mike Brock <cbrock@redhat.com>
* @author Christian Sadilek <csadilek@redhat.com>
*/
@CodeDecorator
public class ObservesExtension extends IOCDecoratorExtension<Observes> {
public ObservesExtension(Class<Observes> decoratesWith) {
super(decoratesWith);
}
@Override
public Statement generateDecorator(InjectableInstance<Observes> instance) {
final Context ctx = instance.getInjectionContext().getProcessingContext().getContext();
final MetaMethod method = instance.getMethod();
final MetaParameter parm = instance.getParm();
final String parmClassName = parm.getType().getFullyQualifiedName();
final Statement bus = instance.getInjectionContext().getInjector(MessageBus.class).getType(instance);
final String subscribeMethodName = method.isAnnotationPresent(Local.class) ? "subscribeLocal" : "subscribe";
final String subject = CDI.getSubjectNameByType(parmClassName);
final Annotation[] qualifiers = InjectUtil.extractQualifiers(instance).toArray(new Annotation[0]);
final Set<String> qualifierNames = CDI.getQualifiersPart(qualifiers);
AnonymousClassStructureBuilderImpl callBack = Stmt.newObject(AbstractCDIEventCallback.class).extend();
BlockBuilder<AnonymousClassStructureBuilderImpl> callBackBlock;
if (qualifierNames != null) {
callBackBlock = callBack.initialize();
for (String qualifierName : qualifierNames) {
callBackBlock.append(Stmt.loadClassMember("qualifiers").invoke("add", qualifierName));
}
callBack = callBackBlock.finish();
}
callBackBlock = callBack.publicOverridesMethod("callback", Parameter.of(Message.class, "message"))
.append(Stmt.declareVariable("msgQualifiers", new TypeLiteral<Set<String>>() {},
Stmt.loadVariable("message").invoke("get", Set.class, CDIProtocol.QUALIFIERS)))
.append(Stmt
.if_(Bool.or(
Stmt.loadClassMember("qualifiers").invoke("equals", Refs.get("msgQualifiers")),
Bool.and(Bool.equals(Refs.get("msgQualifiers"), null),
Stmt.loadClassMember("qualifiers").invoke("isEmpty"))))
.append(Stmt.loadVariable(instance.getInjector().getVarName()).invoke(method.getName(),
Stmt.loadVariable("message").invoke("get", parm.getType().asClass(), CDIProtocol.OBJECT_REF)))
.finish());
return Stmt.create(ctx).nestedCall(bus).invoke(subscribeMethodName, subject, callBackBlock.finish().finish());
}
}