/*
 * 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.modules.input;

import java.io.UnsupportedEncodingException;
import java.util.Map;

import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.configuration.ConfigurationException;
import org.apache.avalon.framework.thread.ThreadSafe;
import org.apache.cocoon.util.NetUtils;

/**
 * This module provides functionality for converting a String from the
 * application/x-www-form-urlencoded MIME format. It is useful for example for
 * calling remote services: <br/>
 * <map:generate src="http://remote/page?param1={url-encode:{request-param:param1}}"/><br/>
 * Module configuration takes only one configuration parameter:
 * "encoding" which is a target string encoding. This is utf-8 by default.
 * 
 * @version $Id$
 */
public final class URLDecodeModule extends AbstractInputModule
                                   implements ThreadSafe {

    public Object getAttribute(String name,
                               Configuration modeConf,
                               Map objectModel) throws ConfigurationException {
        if (name == null) {
            return null;
        }

        String encoding = (String) this.settings.get("encoding", "utf-8");
        try {
            return NetUtils.decode(name, encoding);
        } catch (UnsupportedEncodingException e) {
            throw new ConfigurationException("URLDecodeModule, invalid encoding: " + encoding);
        }
    }
}