// Copyright 2004, 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.binding;
import org.apache.bsf.BSFException;
import org.apache.bsf.BSFManager;
import org.apache.hivemind.ApplicationRuntimeException;
import org.apache.hivemind.Location;
import org.apache.hivemind.util.Defense;
import org.apache.tapestry.IActionListener;
import org.apache.tapestry.IComponent;
import org.apache.tapestry.IPage;
import org.apache.tapestry.IRequestCycle;
import org.apache.tapestry.Tapestry;
import org.apache.tapestry.coerce.ValueConverter;
import org.apache.tapestry.services.BSFManagerFactory;
/**
* A very specialized binding that can be used as an {@link org.apache.tapestry.IActionListener},
* executing a script in a scripting language, via <a href="http://jakarta.apache.org/bsf">Bean
* Scripting Framework </a>.
*
* @author Howard Lewis Ship
* @since 3.0
*/
public class ListenerBinding extends AbstractBinding implements IActionListener
{
private final String _language;
private final String _script;
private final IComponent _component;
/** @since 4.0 */
private BSFManagerFactory _managerFactory;
public ListenerBinding(String description, ValueConverter valueConverter, Location location,
IComponent component, String language, String script,
BSFManagerFactory managerFactory)
{
super(description, valueConverter, location);
Defense.notNull(component, "component");
Defense.notNull(language, "language");
Defense.notNull(script, "script");
_component = component;
_language = language;
_script = script;
_managerFactory = managerFactory;
}
/**
* Returns this.
*/
public Object getObject()
{
return this;
}
/**
* A ListenerBinding is also a {@link org.apache.tapestry.IActionListener}. It registers a
* number of beans with the BSF manager and invokes the script.
* <p>
* Registers the following bean:
* <ul>
* <li>component - the relevant {@link IComponent}, typically the same as the page
* <li>page - the {@link IPage}trigged by the request (obtained by
* {@link IRequestCycle#getPage()}
* <li>cycle - the {@link IRequestCycle}, from which can be found the {@link IEngine}, etc.
* </ul>
*/
public void actionTriggered(IComponent component, IRequestCycle cycle)
{
BSFManager bsf = _managerFactory.createBSFManager();
Location location = getLocation();
try
{
IPage page = cycle.getPage();
bsf.declareBean("component", _component, _component.getClass());
bsf.declareBean("page", page, page.getClass());
bsf.declareBean("cycle", cycle, cycle.getClass());
bsf.exec(
_language,
location.getResource().toString(),
location.getLineNumber(),
location.getLineNumber(),
_script);
}
catch (BSFException ex)
{
String message = Tapestry.format("ListenerBinding.bsf-exception", location, ex
.getMessage());
throw new ApplicationRuntimeException(message, _component, getLocation(), ex);
}
}
/** @since 4.0 */
public Object getComponent()
{
return _component;
}
}