// Copyright 2005 The Apache Software Foundation
//
// 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.apache.tapestry.enhance;
import java.lang.reflect.Modifier;
import org.apache.hivemind.ErrorLog;
import org.apache.hivemind.Location;
import org.apache.hivemind.Messages;
import org.apache.hivemind.service.BodyBuilder;
import org.apache.hivemind.service.MethodSignature;
import org.apache.hivemind.util.Defense;
import org.apache.tapestry.services.ComponentMessagesSource;
import org.apache.tapestry.spec.IComponentSpecification;
/**
* Injects the read-only {@link org.apache.tapestry.IComponent#getMessages() messages}property into
* all components.
*
* @author Howard M. Lewis Ship
* @since 4.0
*/
public class InjectMessagesWorker implements EnhancementWorker
{
final String _messagesProperty = "messages";
final MethodSignature _methodSignature = new MethodSignature(Messages.class, "getMessages",
null, null);
private ErrorLog _errorLog;
private ComponentMessagesSource _componentMessagesSource;
public void performEnhancement(EnhancementOperation op, IComponentSpecification spec)
{
Location location = spec.getLocation();
try
{
injectMessages(op, location);
}
catch (Exception ex)
{
_errorLog.error(EnhanceMessages.errorAddingProperty(_messagesProperty, op
.getBaseClass(), ex), location, ex);
}
}
public void injectMessages(EnhancementOperation op, Location location)
{
Defense.notNull(op, "op");
op.claimReadonlyProperty(_messagesProperty);
String sourceField = op.addInjectedField(
"_$componentMessagesSource",
ComponentMessagesSource.class,
_componentMessagesSource);
op.addField("_$messages", Messages.class);
BodyBuilder builder = new BodyBuilder();
builder.begin();
builder.addln("if (_$messages == null)");
builder.addln(" _$messages = {0}.getMessages(this);", sourceField);
builder.addln("return _$messages;");
builder.end();
op.addMethod(Modifier.PUBLIC, _methodSignature, builder.toString(), location);
}
public void setComponentMessagesSource(ComponentMessagesSource componentMessagesSource)
{
_componentMessagesSource = componentMessagesSource;
}
public void setErrorLog(ErrorLog errorLog)
{
_errorLog = errorLog;
}
}