/*
 * 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.cocoon.components.xpointer;

import org.apache.cocoon.xml.dom.DOMStreamer;
import org.apache.cocoon.ResourceNotFoundException;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.xml.sax.SAXException;

/**
 * Implements support for shorthand XPointers (= id-based lookup). We treat them here as if they
 * were a pointerpart too.
 *
 * <p>Note that although this is implemented here, this feature depends on the presence of a DTD,
 * and a validating parser. Currently, this means its unuseable within Cocoon.
 */
public class ShorthandPart implements PointerPart {
    private String shorthand;

    public ShorthandPart(String shorthand) {
        this.shorthand = shorthand;
    }

    public boolean process(XPointerContext xpointerContext) throws SAXException, ResourceNotFoundException {
        Document document = xpointerContext.getDocument();
        Element element = document.getElementById(shorthand);
        if (element != null) {
            DOMStreamer streamer = new DOMStreamer();
            streamer.setConsumer(xpointerContext.getXmlConsumer());
            streamer.stream(element);
            return true;
        } else {
            if (xpointerContext.getLogger().isDebugEnabled())
                xpointerContext.getLogger().debug("XPointer: found no element with id " + shorthand + " in document " + xpointerContext.getSource().getURI());
        }
        return false;
    }
}