001/* 002 Licensed to the Apache Software Foundation (ASF) under one 003 or more contributor license agreements. See the NOTICE file 004 distributed with this work for additional information 005 regarding copyright ownership. The ASF licenses this file 006 to you under the Apache License, Version 2.0 (the 007 "License"); you may not use this file except in compliance 008 with the License. You may obtain a copy of the License at 009 010 http://www.apache.org/licenses/LICENSE-2.0 011 012 Unless required by applicable law or agreed to in writing, 013 software distributed under the License is distributed on an 014 "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 015 KIND, either express or implied. See the License for the 016 specific language governing permissions and limitations 017 under the License. 018 */ 019package org.apache.wiki.tags; 020 021import java.io.IOException; 022 023import javax.servlet.jsp.JspWriter; 024import javax.servlet.jsp.PageContext; 025 026import org.apache.log4j.Logger; 027import org.apache.wiki.WikiContext; 028import org.apache.wiki.WikiEngine; 029 030/** 031 * Writes difference between two pages using a HTML table. If there is 032 * no difference, includes the body. 033 * 034 * <P><B>Attributes</B></P> 035 * <UL> 036 * <LI>page - Page name to refer to. Default is the current page. 037 * </UL> 038 * 039 * @since 2.0 040 */ 041public class InsertDiffTag extends WikiTagBase { 042 043 private static final long serialVersionUID = 0L; 044 private static final Logger log = Logger.getLogger( InsertDiffTag.class ); 045 046 /** Attribute which is used to store the old page content to the Page Context */ 047 public static final String ATTR_OLDVERSION = "olddiff"; 048 049 /** Attribute which is used to store the new page content to the Page Context */ 050 public static final String ATTR_NEWVERSION = "newdiff"; 051 052 protected String m_pageName; 053 054 /** {@inheritDoc} */ 055 public void initTag() 056 { 057 super.initTag(); 058 m_pageName = null; 059 } 060 061 /** 062 * Sets the page name. 063 * @param page Page to get diff from. 064 */ 065 public void setPage( String page ) 066 { 067 m_pageName = page; 068 } 069 070 /** 071 * Gets the page name. 072 * @return The page name. 073 */ 074 public String getPage() 075 { 076 return m_pageName; 077 } 078 079 /** {@inheritDoc} */ 080 public final int doWikiStartTag() 081 throws IOException 082 { 083 WikiEngine engine = m_wikiContext.getEngine(); 084 WikiContext ctx; 085 086 if( m_pageName == null ) 087 { 088 ctx = m_wikiContext; 089 } 090 else 091 { 092 ctx = (WikiContext)m_wikiContext.clone(); 093 ctx.setPage( engine.getPage(m_pageName) ); 094 } 095 096 Integer vernew = (Integer) pageContext.getAttribute( ATTR_NEWVERSION, 097 PageContext.REQUEST_SCOPE ); 098 Integer verold = (Integer) pageContext.getAttribute( ATTR_OLDVERSION, 099 PageContext.REQUEST_SCOPE ); 100 101 log.debug("Request diff between version "+verold+" and "+vernew); 102 103 if( ctx.getPage() != null ) 104 { 105 JspWriter out = pageContext.getOut(); 106 107 String diff = engine.getDiff( ctx, 108 vernew.intValue(), 109 verold.intValue() ); 110 111 if( diff.length() == 0 ) 112 { 113 return EVAL_BODY_INCLUDE; 114 } 115 116 out.write( diff ); 117 } 118 119 return SKIP_BODY; 120 } 121} 122