zkoss/zk

/* Extendlet.java

    Purpose:
        
    Description:
        
    History:
        Wed Jul  4 15:43:39     2007, Created by tomyeh

Copyright (C) 2007 Potix Corporation. All Rights Reserved.

{{IS_RIGHT
    This program is distributed under LGPL Version 2.1 in the hope that
    it will be useful, but WITHOUT ANY WARRANTY.
}}IS_RIGHT
*/
package org.zkoss.web.util.resource;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * A plugin of {@link ClassWebResource} to process particular
 * content.
 *
 * <p>To add a resource processor to {@link ClassWebResource}, use
 * {@link ClassWebResource#addExtendlet}.
 *
 * @author tomyeh
 * @since 2.4.1
 * @see ClassWebResource#addExtendlet
 */
public interface Extendlet {
    /** Used with {@link #getFeature} to indicate the extendlet can
     * be included directly without going thru Web container.
     *
     * <p>In other words, if getFeature(ALLOW_DIRECT_INCLUDE) is true
     * and a corresponding page is included, then {@link #service}
     * will be invoked directly (rather than calling RequestDispatcher's
     * include method.
     *
     * @since 3.5.2
     */
    public static final int ALLOW_DIRECT_INCLUDE = 0x0001;

    /** Initializes the resource processor.
     */
    public void init(ExtendletConfig config);

    /** Returns if the specified feature is supported.
     * @since 3.5.2
     */
    public boolean getFeature(int feature);

    /** Process the specified request.
     *
     * @param path the path mapped to this resource processor.
     * @since 5.0.0
     */
    public void service(HttpServletRequest request, HttpServletResponse response, String path)
            throws ServletException, IOException;
}