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     */
019    package org.apache.wiki.tags;
020    
021    import javax.servlet.jsp.tagext.BodyContent;
022    import javax.servlet.jsp.tagext.BodyTagSupport;
023    import javax.servlet.jsp.tagext.Tag;
024    
025    /**
026     * ParamTag submits name-value pairs to the first enclosing 
027     * ParamHandler instance. Name and value are strings, and can
028     * be given as tag attributes, or alternatively the value can be 
029     * given as the body contents of this tag. 
030     * <p>
031     * The name-value pair is passed to the closest containing 
032     * ancestor tag that implements ParamHandler. 
033     */
034    public class ParamTag 
035        extends BodyTagSupport
036    {
037    
038        private static final long serialVersionUID = -4671059568218551633L;
039        private String m_name;
040        private String m_value;
041        
042        /**
043         *  {@inheritDoc}
044         */
045        @Override
046        public void release() 
047        {
048            m_name = m_value = null;
049        }
050        
051        /**
052         *  Set the name of the parameter to transfer.
053         *  
054         *  @param s The name.
055         */
056        public void setName( String s ) 
057        {
058            m_name = s;
059        }
060        
061        /**
062         *  Set the value of the parameter to transfer.
063         *  
064         *  @param s The value.
065         */
066        public void setValue( String s ) 
067        {
068            m_value = s;
069        }
070        
071        /**
072         *  {@inheritDoc}
073         */
074        @Override
075        public int doEndTag()
076        {
077            Tag t = null;
078            do
079            {
080                t = getParent();
081            } while (t != null && !(t instanceof ParamHandler));
082    
083            if( t != null )
084            {
085                String val = m_value;
086                if( val == null )
087                {
088                    BodyContent bc = getBodyContent();
089                    if( bc != null ) 
090                    {
091                        val = bc.getString();
092                    }
093                }
094                if( val != null ) 
095                {
096                    ((ParamHandler)t).setContainedParameter( m_name, val );
097                }
098            }
099            
100            
101            return EVAL_PAGE;
102        }
103    }