/*
* Copyright 2011 JBoss, by 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 static org.jboss.errai.codegen.meta.MetaClassFactory.parameterizedAs;
import static org.jboss.errai.codegen.meta.MetaClassFactory.typeParametersOf;
import org.jboss.errai.bus.client.ErraiBus;
import org.jboss.errai.bus.client.framework.Subscription;
import org.jboss.errai.codegen.Context;
import org.jboss.errai.codegen.Parameter;
import org.jboss.errai.codegen.Statement;
import org.jboss.errai.codegen.builder.AnonymousClassStructureBuilder;
import org.jboss.errai.codegen.builder.BlockBuilder;
import org.jboss.errai.codegen.builder.impl.ObjectBuilder;
import org.jboss.errai.codegen.meta.MetaClass;
import org.jboss.errai.codegen.meta.MetaMethod;
import org.jboss.errai.codegen.meta.MetaParameter;
import org.jboss.errai.codegen.util.PrivateAccessType;
import org.jboss.errai.codegen.util.Refs;
import org.jboss.errai.codegen.util.Stmt;
import org.jboss.errai.config.rebind.EnvUtil;
import org.jboss.errai.enterprise.client.cdi.AbstractCDIEventCallback;
import org.jboss.errai.enterprise.client.cdi.api.CDI;
import org.jboss.errai.ioc.client.api.CodeDecorator;
import org.jboss.errai.ioc.client.container.DestructionCallback;
import org.jboss.errai.ioc.rebind.ioc.extension.IOCDecoratorExtension;
import org.jboss.errai.ioc.rebind.ioc.injector.InjectUtil;
import org.jboss.errai.ioc.rebind.ioc.injector.api.InjectableInstance;
import javax.enterprise.event.Observes;
import javax.enterprise.inject.Any;
import java.lang.annotation.Annotation;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
/**
* 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(final Class<Observes> decoratesWith) {
super(decoratesWith);
}
@Override
public List<? extends Statement> generateDecorator(final InjectableInstance<Observes> instance) {
final Context ctx = instance.getInjectionContext().getProcessingContext().getContext();
final MetaMethod method = instance.getMethod();
final MetaParameter parm = instance.getParm();
if (!method.isPublic()) {
instance.ensureMemberExposed(PrivateAccessType.Write);
}
final String parmClassName = parm.getType().getFullyQualifiedName();
final List<Annotation> annotations = InjectUtil.extractQualifiers(instance);
final Annotation[] qualifiers = annotations.toArray(new Annotation[annotations.size()]);
final Set<String> qualifierNames = new HashSet<String>(CDI.getQualifiersPart(qualifiers));
if (qualifierNames.contains(Any.class.getName())) {
qualifierNames.remove(Any.class.getName());
}
MetaClass callBackType = parameterizedAs(AbstractCDIEventCallback.class, typeParametersOf(parm.getType()));
AnonymousClassStructureBuilder callBack = Stmt.newObject(callBackType).extend();
BlockBuilder<AnonymousClassStructureBuilder> callBackBlock;
if (!qualifierNames.isEmpty()) {
callBackBlock = callBack.initialize();
for (String qualifierName : qualifierNames) {
callBackBlock.append(Stmt.loadClassMember("qualifierSet").invoke("add", qualifierName));
}
callBack = callBackBlock.finish();
}
callBackBlock = callBack.publicOverridesMethod("fireEvent", Parameter.finalOf(parm, "event"))
._(instance.callOrBind(Refs.get("event")))
.finish()
.publicOverridesMethod("toString")
._(Stmt.load("Observer: " + parmClassName + " " + Arrays.toString(qualifiers)).returnValue());
final List<Statement> statements = new ArrayList<Statement>();
// create the destruction callback to deregister the service when the bean is destroyed.
final String subscrVar = InjectUtil.getUniqueVarName();
final Statement subscribeStatement =
Stmt.declareVariable(Subscription.class).asFinal().named(subscrVar)
.initializeWith(Stmt.create(ctx).invokeStatic(CDI.class, "subscribe", parmClassName,
callBackBlock.finish().finish()));
statements.add(subscribeStatement);
// create the destruction callback to deregister the service when the bean is destroyed.
final MetaClass destructionCallbackType =
parameterizedAs(DestructionCallback.class, typeParametersOf(instance.getEnclosingType()));
final BlockBuilder<AnonymousClassStructureBuilder> destroyMeth
= ObjectBuilder.newInstanceOf(destructionCallbackType).extend()
.publicOverridesMethod("destroy", Parameter.finalOf(instance.getEnclosingType(), "obj"))
.append(Stmt.loadVariable(subscrVar).invoke("remove"));
for (Class<?> cls : EnvUtil.getAllPortableConcreteSubtypes(parm.getType().asClass())) {
final String subscrHandle = InjectUtil.getUniqueVarName();
statements.add(Stmt.declareVariable(Subscription.class).asFinal().named(subscrHandle)
.initializeWith(Stmt.invokeStatic(ErraiBus.class, "get").invoke("subscribe",
CDI.getSubjectNameByType(cls.getName()),
Stmt.loadStatic(CDI.class, "ROUTING_CALLBACK"))));
destroyMeth.append(Stmt.loadVariable(subscrHandle).invoke("remove"));
}
final Statement destructionCallback = Stmt.create().loadVariable("context").invoke("addDestructionCallback",
Refs.get(instance.getInjector().getInstanceVarName()), destroyMeth.finish().finish());
statements.add(destructionCallback);
return statements;
}
}