| // Copyright 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.tapestry.binding; |
| |
| import org.apache.bsf.BSFException; |
| import org.apache.bsf.BSFManager; |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| import org.apache.tapestry.ApplicationRuntimeException; |
| import org.apache.tapestry.BindingException; |
| import org.apache.tapestry.IActionListener; |
| import org.apache.tapestry.IComponent; |
| import org.apache.tapestry.IEngine; |
| import org.apache.tapestry.ILocation; |
| import org.apache.tapestry.IPage; |
| import org.apache.tapestry.IRequestCycle; |
| import org.apache.tapestry.Tapestry; |
| import org.apache.tapestry.util.pool.Pool; |
| |
| /** |
| * 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 |
| * @version $Id$ |
| * @since 3.0 |
| * |
| **/ |
| |
| public class ListenerBinding extends AbstractBinding implements IActionListener |
| { |
| private static final Log LOG = LogFactory.getLog(ListenerBinding.class); |
| |
| private static final String BSF_POOL_KEY = "org.apache.tapestry.BSFManager"; |
| |
| private String _language; |
| private String _script; |
| private IComponent _component; |
| |
| public ListenerBinding(IComponent component, String language, String script, ILocation location) |
| { |
| super(location); |
| |
| _component = component; |
| _language = language; |
| _script = script; |
| } |
| |
| /** |
| * Always returns true. |
| * |
| **/ |
| |
| public boolean getBoolean() |
| { |
| return true; |
| } |
| |
| public int getInt() |
| { |
| throw new BindingException( |
| Tapestry.format("ListenerBinding.invalid-access", "getInt()"), |
| this); |
| } |
| |
| public double getDouble() |
| { |
| throw new BindingException( |
| Tapestry.format("ListenerBinding.invalid-access", "getDouble()"), |
| this); |
| |
| } |
| |
| /** |
| * Returns the underlying script. |
| * |
| **/ |
| |
| public String getString() |
| { |
| return _script; |
| } |
| |
| /** |
| * 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) |
| { |
| boolean debug = LOG.isDebugEnabled(); |
| |
| long startTime = debug ? System.currentTimeMillis() : 0; |
| |
| BSFManager bsf = obtainBSFManager(cycle); |
| |
| ILocation 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.getResourceLocation().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); |
| } |
| finally |
| { |
| if (LOG.isDebugEnabled()) |
| LOG.debug("Cleaning up " + bsf); |
| |
| undeclare(bsf, "component"); |
| undeclare(bsf, "page"); |
| undeclare(bsf, "cycle"); |
| |
| cycle.getEngine().getPool().store(BSF_POOL_KEY, bsf); |
| |
| if (debug) |
| { |
| long endTime = System.currentTimeMillis(); |
| |
| LOG.debug( |
| "Execution of \"" + location + "\" took " + (endTime - startTime) + " millis"); |
| } |
| } |
| } |
| |
| private void undeclare(BSFManager bsf, String name) |
| { |
| try |
| { |
| bsf.undeclareBean(name); |
| } |
| catch (BSFException ex) |
| { |
| LOG.warn(Tapestry.format("ListenerBinding.unable-to-undeclare-bean", ex)); |
| } |
| } |
| |
| private BSFManager obtainBSFManager(IRequestCycle cycle) |
| { |
| IEngine engine = cycle.getEngine(); |
| Pool pool = engine.getPool(); |
| |
| BSFManager result = (BSFManager) pool.retrieve(BSF_POOL_KEY); |
| |
| if (result == null) |
| { |
| LOG.debug("Creating new BSFManager instance."); |
| |
| result = new BSFManager(); |
| |
| result.setClassLoader(engine.getResourceResolver().getClassLoader()); |
| } |
| |
| return result; |
| } |
| } |