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.plugin;
020    
021    import java.util.Map;
022    
023    import org.apache.wiki.WikiContext;
024    import org.apache.wiki.api.exceptions.PluginException;
025    import org.apache.wiki.api.plugin.WikiPlugin;
026    import org.apache.wiki.util.TextUtil;
027    
028    /**
029     *  Provides a page-specific counter, it is reset every time a page is rendered, so it is not usable as a hitcounter.
030     *  <br>Stores a variable in the WikiContext called "counter", with the name of the optionally specified variable "name".  
031     *  <br>For example:  If name is "thispage", then the variable name is called "counter-thispage".
032     *
033     *  <p>Parameters : </p>
034     *  <ul>
035     *  <li><b>name</b> - Name of the counter.  Optional.</li>
036     *  <li><b>increment</b> - The amount to increment, may be a negative value, default is 1.  Optional.</li>
037     *  <li><b>showResult</b> - Should the counter value be visible on the page, default is true.  Optional.</li>
038     *  </ul>
039     *
040     *  @since 1.9.30
041     */
042    public class Counter
043        implements WikiPlugin
044    {
045        // private static Logger log = Logger.getLogger( Counter.class );
046    
047        /** Parameter name for setting the name.  Value is <tt>{@value}</tt>. */
048        public static final String  PARAM_NAME          = "name";
049        /** Parameter name for setting the increment.  Value is <tt>{@value}</tt>. */
050        public static final String  PARAM_INCREMENT     = "increment";
051        /** Parameter name for setting the showResult.  Value is <tt>{@value}</tt>. */
052        public static final String  PARAM_SHOW_RESULT   = "showResult";
053        /** Parameter name for setting the start.  Value is <tt>{@value}</tt>. */
054        public static final String  PARAM_START         = "start";
055        public static final String  DEFAULT_NAME        = "counter";
056        private static final int     DEFAULT_INCREMENT   = 1;
057        private static final boolean DEFAULT_SHOW_RESULT = true;
058    
059        /**
060         *  {@inheritDoc}
061         */
062        public String execute( WikiContext context, Map<String, String> params )
063            throws PluginException
064        {
065            //
066            //  First, determine which kind of name we use to store in
067            //  the WikiContext.
068            //
069            String  countername = params.get(  PARAM_NAME);
070    
071            if( countername == null ) 
072            {
073                countername = DEFAULT_NAME;
074            }
075            else
076            {
077                countername = DEFAULT_NAME+"-"+countername;
078            }
079    
080            //
081            //  Fetch the old value
082            //
083            Integer val = (Integer)context.getVariable( countername );
084    
085            if( val == null )
086            {
087                val = 0;
088            }
089            
090            //
091            //  Check if we need to reset this
092            //
093            
094            String start = params.get( PARAM_START );
095            
096            if( start != null )
097            {
098                val = Integer.parseInt( start );
099            }
100            else
101            {
102                //
103                //  Determine how much to increment
104                //
105                String incrementObj = params.get( PARAM_INCREMENT );
106            
107                int increment = DEFAULT_INCREMENT;
108            
109                if (incrementObj != null) 
110                {
111                    increment = ( Integer.valueOf( incrementObj ) ).intValue();
112                }
113    
114                val = val + increment;
115            }
116            
117            context.setVariable( countername, val );
118    
119            //
120            // check if we want to hide the result (just count, don't show result on the page
121            //
122            String showObj = params.get(PARAM_SHOW_RESULT);
123            
124            boolean show = DEFAULT_SHOW_RESULT;
125            
126            if( showObj != null ) 
127            {
128                show = TextUtil.isPositive( showObj );
129            }
130            
131            if( show )
132            {
133                return val.toString();
134            } 
135           
136            return "";
137        }
138    
139    }