org.apache.myfaces.custom.updateactionlistener.UpdateActionListenerTagHandler Maven / Gradle / Ivy

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JSF components and utilities that can be used with any JSF implementation. This library is based on the JSF1.1 version of Tomahawk, but with minor source code and build changes to take advantage of JSF2.1 features. A JSF2.1 implementation is required to use this version of the Tomahawk library.

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/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.myfaces.custom.updateactionlistener;

import java.io.IOException;

import javax.el.ELException;
import javax.faces.FacesException;
import javax.faces.application.Application;
import javax.faces.component.ActionSource;
import javax.faces.component.UIComponent;
import javax.faces.convert.Converter;
import javax.faces.event.ActionListener;
import javax.faces.view.facelets.ComponentConfig;
import javax.faces.view.facelets.FaceletContext;
import javax.faces.view.facelets.FaceletException;
import javax.faces.view.facelets.TagAttribute;
import javax.faces.view.facelets.TagConfig;
import javax.faces.view.facelets.TagHandler;
import javax.faces.webapp.UIComponentTag;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * Tag handler for the Tomahawk UpdateActionListener tag
 * 
 * @since 1.1.7
 * @author arobinson74
 */
public class UpdateActionListenerTagHandler extends TagHandler
{
    private static Log logger = LogFactory
            .getLog(UpdateActionListenerTagHandler.class);

    private TagAttribute converterAttr;
    private TagAttribute propertyAttr;
    private TagAttribute valueAttr;

    /**
     * @param config
     */
    public UpdateActionListenerTagHandler(ComponentConfig config)
    {
        this((TagConfig) config);
    }

    /**
     * @param config
     */
    public UpdateActionListenerTagHandler(TagConfig config)
    {
        super(config);
        valueAttr = getRequiredAttribute("value");
        propertyAttr = getRequiredAttribute("property");
        converterAttr = getAttribute("converter");
    }

    /**
     * @see com.sun.facelets.FaceletHandler#apply(com.sun.facelets.FaceletContext, javax.faces.component.UIComponent)
     */
    public void apply(FaceletContext ctx, UIComponent parent)
            throws IOException, FacesException, FaceletException, ELException
    {
        logger.debug("Apply called. Component: " + parent);
        ActionSource actionSource = (ActionSource) parent;

        if (sourceHasProperty(actionSource))
            return;

        UpdateActionListener al = new UpdateActionListener();

        Application app = ctx.getFacesContext().getApplication();
        if (converterAttr != null)
        {
            Converter converter = app.createConverter(converterAttr
                    .getValue(ctx));
            al.setConverter(converter);
        }

        String value = valueAttr.getValue();
        if (UIComponentTag.isValueReference(value))
            al.setValueBinding(app.createValueBinding(valueAttr.getValue()));
        else
            al.setValue(value);

        al.setPropertyBinding(app.createValueBinding(propertyAttr.getValue()));

        actionSource.addActionListener(al);
    }

    private boolean sourceHasProperty(ActionSource source)
    {
        ActionListener[] listeners = source.getActionListeners();
        for (int i = 0; i < listeners.length; i++)
        {
            ActionListener listener = listeners[i];
            if (listener instanceof UpdateActionListener == false)
                continue;
            UpdateActionListener al = (UpdateActionListener) listener;
            if (al.getPropertyBinding().getExpressionString().equals(
                    this.propertyAttr.getValue()))
            {
                logger.debug("Action listener already has a listener for "
                        + this.propertyAttr.getValue());
                return true;
            }
        }
        logger.debug("Action listener for property is not present. Property: "
                + this.propertyAttr.getValue());
        return false;
    }
}