package org.apache.turbine.services.avaloncomponent;

/* ====================================================================
 * The Apache Software License, Version 1.1
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 * Copyright (c) 2001-2003 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
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 * 1. Redistributions of source code must retain the above copyright
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 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
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 *    if and wherever such third-party acknowledgments normally appear.
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 * 4. The names "Apache" and "Apache Software Foundation" and
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 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

import org.apache.avalon.framework.component.Component;
import org.apache.avalon.framework.component.ComponentException;

import org.apache.turbine.services.Service;

/**
 * This service allows access to avalon components.
 *
 * @author <a href="mailto:quintonm@bellsouth.net">Quinton McCombs</a>
 * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
 * @version $Id$
 */
public interface AvalonComponentService
        extends Service
{
    /** The publically visible name of the service */
    String SERVICE_NAME = "AvalonComponentService";

    /** Where we write the Avalon Logger messages */
    String AVALON_LOG_CATEGORY = "avalon";

    /** property specifing file name of the component config file */
    String COMPONENT_CONFIG_KEY = "componentConfiguration";

    /** property specifing file name of the component config file */
    String COMPONENT_CONFIG_VALUE = "/WEB-INF/conf/componentConfiguration.xml";

    /** property specifing file name of the component role file */
    String COMPONENT_ROLE_KEY = "componentRoles";

    /** property specifing file name of the component role file */
    String COMPONENT_ROLE_VALUE = "/WEB-INF/conf/roleConfiguration.xml";

    /** property for the Components to look up */
    String COMPONENT_LOOKUP_KEY = "lookup";

    /** Key used in the context for defining the application root */
    String COMPONENT_APP_ROOT = "componentAppRoot";

    /**
     * Returns an instance of the named component
     *
     * @param roleName Name of the role the component fills.
     * @return an instance of the named component
     * @throws ComponentException generic exception
     */
    Component lookup(String roleName)
            throws ComponentException;

    /**
     * Releases the component
     *
     * @param component the component to release
     */
    void release(Component component);

}