PreprocessingFilter.java

/*
 * Copyright 2007 Wilfred Springer
 *
 * 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 com.agilejava.docbkx.maven;

import java.util.List;

import org.xml.sax.SAXException;
import org.xml.sax.XMLFilter;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.XMLFilterImpl;

/**
 * A {@link XMLFilter} managing a collection of
 * {@link ProcessingInstructionHandler ProcessingInstructionHandlers}, using
 * them to handle processing instructions encountered while parsing the XML
 * document.
 *
 * @author Wilfred Springer
 *
 */
public class PreprocessingFilter extends XMLFilterImpl {

    /**
     * The list of {@link ProcessingInstructionHandler} instances to which this
     * object might delegate.
     */
    private List handlers;

    /**
     * Constructs a new instance.
     *
     * @param reader The parent reader.
     */
    public PreprocessingFilter(XMLReader parent) {
        super(parent);
    }

    // JavaDoc inherited
    public void processingInstruction(String target, String data)
            throws SAXException {
        for (int i = handlers.size() - 1; i >= 0; i--) {
            ProcessingInstructionHandler handler = (ProcessingInstructionHandler) handlers
                    .get(i);
            if (handler.matches(target)) {
                handler.handle(data, this);
                return;
            }
        }
        super.processingInstruction(target, data);
    }

    /**
     * Sets the list of handlers.
     *
     * @param handlers The list of handlers to which this filter might delegate.
     */
    public void setHandlers(List handlers) {
        this.handlers = handlers;
    }

    /**
     * Returns the list of handlers.
     *
     * @return The list of handlers to which this filter might delegate.
     */
    public List getHandlers() {
        return handlers;
    }

}