framework/src/net/sf/tapestry/IEngineServiceView.java

/*
 *  ====================================================================
 *  The Apache Software License, Version 1.1
 *
 *  Copyright (c) 2002 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:
 *
 *  1. Redistributions of source code must retain the above copyright
 *  notice, this list of conditions and the following disclaimer.
 *
 *  2. Redistributions in binary form must reproduce the above copyright
 *  notice, this list of conditions and the following disclaimer in
 *  the documentation and/or other materials provided with the
 *  distribution.
 *
 *  3. The end-user documentation included with the redistribution,
 *  if any, must include the following acknowledgment:
 *  "This product includes software developed by the
 *  Apache Software Foundation (http://www.apache.org/)."
 *  Alternately, this acknowledgment may appear in the software itself,
 *  if and wherever such third-party acknowledgments normally appear.
 *
 *  4. The names "Apache" and "Apache Software Foundation" and
 *  "Apache Tapestry" must not be used to endorse or promote products
 *  derived from this software without prior written permission. For
 *  written permission, please contact apache@apache.org.
 *
 *  5. Products derived from this software may not be called "Apache",
 *  "Apache Tapestry", nor may "Apache" appear in their name, without
 *  prior written permission of the Apache Software Foundation.
 *
 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 *  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 *  DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 *  ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 *  USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 *  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 *  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 *  OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 *  SUCH DAMAGE.
 *  ====================================================================
 *
 *  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/>.
 */
package net.sf.tapestry;

import java.io.IOException;

import javax.servlet.ServletException;

/**
 *  Additional methods implemented by the engine that are 
 *  exposed to {@link IEngineService engine services}.
 *
 *  @author Howard Lewis Ship
 *  @version $Id$
 *  @since 1.0.9
 *
 */

public interface IEngineServiceView extends IEngine
{
    /**
     *  Invoked by a service to force the page selected by the {@link IRequestCycle}
     *  to be renderred.  This takes care of a number of bookkeeping issues, such
     *  as committing changes in page recorders.
     * 
     **/

    public void renderResponse(IRequestCycle cycle, ResponseOutputStream output)
        throws RequestCycleException, ServletException, IOException;

    /**
     *  Invoked to restart the application from start; this most frequently follows
     *  some kind of catastrophic failure.  This will invalidate any {@link javax.servlet.http.HttpSession}
     *  and force a redirect to the application servlet (i.e., invoking the home service
     *  in a subsequent request cycle).
     * 
     **/

    public void restart(IRequestCycle cycle) throws IOException;

    /**
     *  Invoked (typically by the reset service) to clear all cached data known
     *  to the engine.  This includes 
     *  pages, templates, helper beans, specifications,
     *  localized strings, etc., and
     *  is used during debugging.
     * 
     **/

    public void clearCachedData();

    /**
     *  Writes a detailed report of the exception to <code>System.err</code>.
     *  This is invoked by services that can't write an HTML description
     *  of the error because they don't provide text/html content (such as
     *  an asset that creates an image).
     *
     *  @since 1.0.10
     */

    public void reportException(String reportTitle, Throwable ex);
}