src/java/org/apache/lenya/cms/cocoon/components/modules/input/CustomMetaDataModule.java

/*
 * Copyright  1999-2005 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.
 *
 */

/* $Id: DublinCoreModule.java 169299 2005-05-09 12:00:43Z jwkaltz $  */

package org.apache.lenya.cms.cocoon.components.modules.input;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.Map;

import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.configuration.ConfigurationException;
import org.apache.avalon.framework.service.ServiceException;
import org.apache.avalon.framework.service.ServiceManager;
import org.apache.avalon.framework.service.Serviceable;
import org.apache.cocoon.components.modules.input.AbstractInputModule;
import org.apache.cocoon.environment.ObjectModelHelper;
import org.apache.cocoon.environment.Request;
import org.apache.lenya.cms.repo.Document;
import org.apache.lenya.cms.repo.RepositoryException;
import org.apache.lenya.cms.repo.impl.RepositoryUtil;
import org.apache.lenya.cms.repo.metadata.MetaData;

/**
 * Input module to access custom meta data values.
 */
public class CustomMetaDataModule extends AbstractInputModule implements Serviceable {

    final static String NS_PREFIX = "lenya:";

    /**
     * @see org.apache.cocoon.components.modules.input.InputModule#getAttribute(java.lang.String,
     *      org.apache.avalon.framework.configuration.Configuration, java.util.Map)
     */
    public Object getAttribute(String name, Configuration modeConf, Map objectModel)
            throws ConfigurationException {
        Object value;

        try {
            MetaData metaData = getCustomMetaData(objectModel);
            if (!metaData.getElementSet().contains(NS_PREFIX + name)) {
                throw new ConfigurationException("The attribute [" + name + "] is not supported!");
            }
            value = metaData.getValue(NS_PREFIX + name);
        } catch (RepositoryException e) {
            throw new ConfigurationException("Obtaining custom meta data value for [" + name
                    + "] failed: ", e);
        }

        return value;
    }

    /**
     * @see org.apache.cocoon.components.modules.input.InputModule#getAttributeNames(org.apache.avalon.framework.configuration.Configuration,
     *      java.util.Map)
     */
    public Iterator getAttributeNames(Configuration modeConf, Map objectModel)
            throws ConfigurationException {

        // No pre-defined attributes. Return empty iterator.
        return new ArrayList().iterator();
    }

    /**
     * @see org.apache.cocoon.components.modules.input.InputModule#getAttributeValues(java.lang.String,
     *      org.apache.avalon.framework.configuration.Configuration, java.util.Map)
     */
    public Object[] getAttributeValues(String name, Configuration modeConf, Map objectModel)
            throws ConfigurationException {
        Object[] values;

        try {
            MetaData metaData = getCustomMetaData(objectModel);
            if (!metaData.getElementSet().contains(NS_PREFIX + name)) {
                throw new ConfigurationException("The attribute [" + name + "] is not supported!");
            }

            values = metaData.getValues(NS_PREFIX + name);
        } catch (RepositoryException e) {
            throw new ConfigurationException("Obtaining custom meta data value for [" + name
                    + "] failed: ", e);
        }

        return values;
    }

    protected MetaData getCustomMetaData(Map objectModel) throws ConfigurationException {
        // FIXME: There seems to be no reason to pass the attribute name to get the page envelope.
        MetaData metaData = null;
        try {
            Request request = ObjectModelHelper.getRequest(objectModel);
            Document document = RepositoryUtil.getDocument(this.manager, request, getLogger());
            if (document == null) {
                throw new ConfigurationException("There is no document for this page envelope!");
            }
            metaData = document.getMetaData("custom");
        } catch (RepositoryException e) {
            throw new ConfigurationException("Obtaining custom meta data value failed: ", e);
        }
        return metaData;
    }

    protected ServiceManager manager;

    public void service(ServiceManager manager) throws ServiceException {
        this.manager = manager;

    }
}