/*
 * File   : $Source: /usr/local/cvs/opencms/src/org/opencms/configuration/I_CmsConfigurationParameterHandler.java,v $
 * Date   : $Date: 2008-02-27 12:05:48 $
 * Version: $Revision: 1.11 $
 *
 * This library is part of OpenCms -
 * the Open Source Content Management System
 *
 * Copyright (c) 2002 - 2008 Alkacon Software GmbH (http://www.alkacon.com)
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * For further information about Alkacon Software GmbH, please see the
 * company website: http://www.alkacon.com
 *
 * For further information about OpenCms, please see the
 * project website: http://www.opencms.org
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package org.opencms.configuration;

import java.util.Map;

/**
 * Used for classes that are configurable using 
 * <code>&lt;param name="name"&gt;value&lt;/param&gt;</code> 
 * in the XML configuration.<p>
 * 
 * Such "param" nodes can be used to add some arbitary names 
 * parameters to classes that otherwise share the same XML configuration.
 * 
 * @author Alexander Kandzior 
 * 
 * @version $Revision: 1.11 $
 * 
 * @since 6.0.0
 */
public interface I_CmsConfigurationParameterHandler {
    
    /** The name of the addConfigurationParameter() method. */
    String ADD_PARAMETER_METHOD = "addConfigurationParameter";
    
    /** The name of the initConfiguration() method. */
    String INIT_CONFIGURATION_METHOD = "initConfiguration";    
    
    /**
     * Adds a configuration parameter to this parameter configurable class instance.<p>
     * 
     * @param paramName the name of the parameter 
     * @param paramValue the value for the parameter
     */
    void addConfigurationParameter(String paramName, String paramValue);
    
    /**
     * Returns the configuration of this parameter configurable class instance,
     * or <code>null</code> if the class does not need to be configured.<p>
     * 
     * All elements in the configuration are key, value String pairs,
     * set using the {@link #addConfigurationParameter(String, String)} method
     * during initialization of the loader.<p>
     * 
     * Implementations will (should) not to return a direct reference to
     * the internal configuration but just a copy of it, to avoid 
     * unwanted external manipulation.<p>
     * 
     * @return the configuration of this resource loader, or <code>null</code>
     */
    Map getConfiguration();
    
    /**
     * Initializes a configuration after all parameters have been added.<p>
     * 
     * @throws CmsConfigurationException if something goes wrong
     */
    void initConfiguration() throws CmsConfigurationException;
}
