org.wings.template.parser.SpecialTagHandler Maven / Gradle / Ivy
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* Copyright (c) 1997-1999 The Java Apache Project. 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
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* the documentation and/or other materials provided with the
* distribution.
*
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by the Java Apache
* Project for use in the Apache JServ servlet engine project
* (http://java.apache.org/)."
*
* 4. The names "Apache JServ", "Apache JServ Servlet Engine" and
* "Java Apache Project" must not be used to endorse or promote products
* derived from this software without prior written permission.
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* 5. Products derived from this software may not be called "Apache JServ"
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* acknowledgment:
* "This product includes software developed by the Java Apache
* Project for use in the Apache JServ servlet engine project
* (http://java.apache.org/)."
*
* THIS SOFTWARE IS PROVIDED BY THE JAVA APACHE PROJECT "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 JAVA APACHE PROJECT 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 Java Apache Group. For more information
* on the Java Apache Project and the Apache JServ Servlet Engine project,
* please see SpecialTagHandler represents a tag which requires
* handling within server side parsed page. This could be a
* class handling <SERVLET>-Tags or any other tag. See
* PageParser, SSI and ParameterPropagatingSSI for examples.
*
* A class to plug into PageParser must implement
* this interface and must have a simple constructor
* without parameters and can then be added with
* addTagHandler() to a PageParser servlet.
*
* @author Henner Zeller
*/
/*
* Copyright 2000,2005 wingS development team.
*
* This file is part of wingS (http://wingsframework.org).
*
* wingS 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.
*
* Please see COPYING for the complete licence.
*/
package org.wings.template.parser;
import java.io.IOException;
import java.io.Reader;
public interface SpecialTagHandler {
/**
* Parse tag.
* This method is invoked if a tag with a name
* this class is registered for is found.
* It gets the ServletConfiguration of the PageParser
* servet and a PositionReader, placed after name of
* the current tag.
* The parseTag() method is called before
* any processing is done. Its purpose is to parse the area
* this tag spans and probably read in parameters used at
* execution time.
* This method returns the last tag belonging to the
* area handled by this handler (for server side included
* servlets, this would be </SERVLET>).
* For simple one-tag Handlers this is simply the tag passed
* to this method. If the Handler decides not to handle this tag, this
* method should return null.
*
* @param context The context used while parsing; contains
* at least the HttpServletRequest and HttpServletResponse.
* @param input The PositionReader, located after the Name token
* of the Tag
* @param startPos The Position parsing of this token began
* @param startTag the SGMLTag found in the file.
*/
SGMLTag parseTag(ParseContext context,
PositionReader input,
long startPos,
SGMLTag startTag)
throws IOException;
/**
* Get start position of the area in the sourcefile this
* handler processes.
* This is usually the position of the "<"
* of the <SpecialTag> within the inputfile.
*/
long getTagStart();
/**
* Get the length of the area in the sourcefile.
* The area this handler processes is skipped in the inputfile.
* Usually this represents the length of the single
* <SpecialTag> or the
* area <SpecialTag>...</SpecialTag>
*/
long getTagLength();
/**
* actually perform the action associated with this tag.
*
* @throws Exception anything can happen .. and throw an Exception
* which is caught in PageParser
*/
void executeTag(ParseContext context, Reader input)
throws Exception;
}