/*
 * Copyright 2005-2011 the original author or authors.
 * 
 * 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 org.wamblee.xmlrouter.impl;

import java.util.logging.Level;
import java.util.logging.Logger;

import javax.xml.transform.dom.DOMSource;

import org.wamblee.xmlrouter.config.Filter;

/**
 * This class provides robustness towards externally supplied filters.
 * 
 * @author Erik Brakkee
 * 
 */
public class RobustFilter extends RobustIdentifiable<Filter> implements Filter {

    private static final Logger LOGGER = Logger.getLogger(RobustFilter.class
        .getName());

    private Filter filter;

    /**
     * Constructs the wrapper.
     * 
     * @param aPrefix
     *            prefix to use for ids.
     * @param aId
     *            Id.
     * @param aFilter
     *            Filter to wrap.
     */
    public RobustFilter(String aPrefix, Filter aFilter) {
        super(aPrefix, aFilter);
        filter = aFilter;
    }

    @Override
    public boolean isAllowed(String aDocumentType, DOMSource aSource) {
        try {
            return filter.isAllowed(aDocumentType, aSource);
        } catch (Exception e) {
            LOGGER.log(Level.WARNING, "Filter " + getId() +
                " threw exception, assuming filter returns true", e);
            return true;
        }
    }
}