/*
* Copyright 1999-2004 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.cocoon.components;
import java.util.Map;
import org.apache.avalon.framework.component.Component;
import org.apache.avalon.framework.component.ComponentException;
import org.apache.avalon.framework.component.ComponentManager;
import org.apache.avalon.framework.component.ComponentSelector;
import org.apache.avalon.framework.context.Context;
import org.apache.avalon.framework.context.ContextException;
import org.apache.avalon.framework.context.DefaultContext;
import org.apache.avalon.framework.service.ServiceException;
import org.apache.avalon.framework.service.ServiceManager;
import org.apache.avalon.framework.service.ServiceSelector;
import org.apache.cocoon.environment.Environment;
/**
* This is the {@link Context} implementation for Cocoon components.
* It extends the {@link DefaultContext} by a special handling for
* getting objects from the object model and other application information.
*
* @see org.apache.cocoon.components.ContextHelper
* @author <a href="mailto:cziegeler@apache.org">Carsten Ziegeler</a>
* @version CVS $Id: ComponentContext.java,v 1.6 2004/05/16 15:20:48 cziegeler Exp $
*/
public class ComponentContext
extends DefaultContext {
protected static final String OBJECT_MODEL_KEY_PREFIX = ContextHelper.CONTEXT_OBJECT_MODEL + '.';
/**
* Create a Context with specified data and parent.
*
* @param contextData the context data
* @param parent the parent Context (may be null)
*/
public ComponentContext(final Map contextData, final Context parent) {
super( contextData, parent );
}
/**
* Create a Context with specified data.
*
* @param contextData the context data
*/
public ComponentContext(final Map contextData) {
super( contextData );
}
/**
* Create a Context with specified parent.
*
* @param parent the parent Context (may be null)
*/
public ComponentContext(final Context parent) {
super( parent );
}
/**
* Create a Context with no parent.
*
*/
public ComponentContext() {
super();
}
/**
* Retrieve an item from the Context.
*
* @param key the key of item
* @return the item stored in context
* @throws ContextException if item not present
*/
public Object get( final Object key )
throws ContextException {
if ( ContextHelper.CONTEXT_OBJECT_MODEL.equals(key)) {
final Environment env = CocoonComponentManager.getCurrentEnvironment();
if ( env == null ) {
throw new ContextException("Unable to locate " + key + " (No environment available)");
}
return env.getObjectModel();
} else if ( ContextHelper.CONTEXT_SITEMAP_SERVICE_MANAGER.equals(key)) {
final ComponentManager manager = CocoonComponentManager.getSitemapComponentManager();
if ( manager == null ) {
throw new ContextException("Unable to locate " + key + " (No environment available)");
}
return new ComponentManagerWrapper(manager);
}
if ( key instanceof String ) {
String stringKey = (String)key;
if ( stringKey.startsWith(OBJECT_MODEL_KEY_PREFIX) ) {
final Environment env = CocoonComponentManager.getCurrentEnvironment();
if ( env == null ) {
throw new ContextException("Unable to locate " + key + " (No environment available)");
}
final Map objectModel = env.getObjectModel();
String objectKey = stringKey.substring(OBJECT_MODEL_KEY_PREFIX.length());
Object o = objectModel.get( objectKey );
if ( o == null ) {
final String message = "Unable to locate " + key;
throw new ContextException( message );
}
return o;
}
}
return super.get( key );
}
public static final class ComponentManagerWrapper implements ServiceManager {
protected final ComponentManager manager;
public ComponentManagerWrapper(ComponentManager m) {
this.manager = m;
}
/* (non-Javadoc)
* @see org.apache.avalon.framework.service.ServiceManager#hasService(java.lang.String)
*/
public boolean hasService(String role) {
return this.manager.hasComponent(role);
}
/* (non-Javadoc)
* @see org.apache.avalon.framework.service.ServiceManager#lookup(java.lang.String)
*/
public Object lookup(String role) throws ServiceException {
try {
Object o = this.manager.lookup(role);
if ( o instanceof ComponentSelector ) {
o = new ComponentSelectorWrapper((ComponentSelector)o);
}
return o;
} catch (ComponentException ce) {
throw new ServiceException("ComponentManagerWrapper", "Unable to lookup component: " + role, ce);
}
}
/* (non-Javadoc)
* @see org.apache.avalon.framework.service.ServiceManager#release(java.lang.Object)
*/
public void release(Object c) {
if ( c instanceof ComponentSelectorWrapper ) {
c = ((ComponentSelectorWrapper)c).getComponent();
}
this.manager.release((Component)c);
}
}
public static final class ComponentSelectorWrapper implements ServiceSelector {
protected final ComponentSelector selector;
public ComponentSelectorWrapper(ComponentSelector s) {
this.selector = s;
}
/* (non-Javadoc)
* @see org.apache.avalon.framework.service.ServiceSelector#isSelectable(java.lang.Object)
*/
public boolean isSelectable(Object role) {
return this.selector.hasComponent(role);
}
/* (non-Javadoc)
* @see org.apache.avalon.framework.service.ServiceSelector#release(java.lang.Object)
*/
public void release(Object role) {
this.selector.release((Component)role);
}
/* (non-Javadoc)
* @see org.apache.avalon.framework.service.ServiceSelector#select(java.lang.Object)
*/
public Object select(Object role) throws ServiceException {
try {
Object o = this.selector.select(role);
if ( o instanceof ComponentSelector ) {
o = new ComponentSelectorWrapper((ComponentSelector)o);
}
return o;
} catch (ComponentException ce) {
throw new ServiceException("ComponentServiceWrapper", "Unable to lookup component: " + role, ce);
}
}
public ComponentSelector getComponent() {
return this.selector;
}
}
}