001/*
002 * (C) Copyright 2006-2010 Nuxeo SA (http://nuxeo.com/) and others.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 *
016 * Contributors:
017 *     <a href="mailto:at@nuxeo.com">Anahide Tchertchian</a>
018 *
019 * $Id$
020 */
021
022package org.nuxeo.ecm.platform.ui.web.tag.handler;
023
024import java.io.IOException;
025
026import javax.el.ELException;
027import javax.faces.FacesException;
028import javax.faces.component.ActionSource;
029import javax.faces.component.UIComponent;
030import javax.faces.event.ActionEvent;
031import javax.faces.event.ActionListener;
032import javax.faces.event.MethodExpressionActionListener;
033import javax.faces.view.facelets.FaceletContext;
034import javax.faces.view.facelets.FaceletException;
035import javax.faces.view.facelets.TagAttribute;
036import javax.faces.view.facelets.TagConfig;
037import javax.faces.view.facelets.TagException;
038import javax.faces.view.facelets.TagHandler;
039
040import org.nuxeo.ecm.platform.ui.web.binding.MetaMethodExpression;
041
042/**
043 * Action listener method handler: makes it possible to add an action listener method to any action source component
044 * parent.
045 * <p>
046 * This is useful when declaring several action listeners on the same parent component, and when the order of calls
047 * needs to be respected: the action listener method declared on a component is the first one called. So this method
048 * makes it possible to add other action listeners before it, without having to declare a class (when using the
049 * f:actionListener tag).
050 *
051 * @author Anahide Tchertchian
052 */
053public class ActionListenerMethodTagHandler extends TagHandler {
054
055    protected final TagAttribute value;
056
057    @SuppressWarnings("rawtypes")
058    public static final Class[] ACTION_LISTENER_SIG = { ActionEvent.class };
059
060    public ActionListenerMethodTagHandler(TagConfig config) {
061        super(config);
062        value = getRequiredAttribute("value");
063    }
064
065    @Override
066    public void apply(FaceletContext ctx, UIComponent parent)
067            throws IOException, FacesException, FaceletException, ELException {
068        if (parent instanceof ActionSource) {
069            // only process if parent was just created
070            if (parent.getParent() == null) {
071                ActionSource src = (ActionSource) parent;
072                ActionListener listener = new MethodExpressionActionListener(
073                        new MetaMethodExpression(value.getMethodExpression(ctx, null, ACTION_LISTENER_SIG),
074                                ctx.getFunctionMapper(), ctx.getVariableMapper()));
075                src.addActionListener(listener);
076            }
077        } else {
078            throw new TagException(tag, "Parent is not of type ActionSource, type is: " + parent);
079        }
080    }
081
082}