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.plugin;
020
021import java.util.Map;
022
023import org.apache.wiki.WikiContext;
024import org.apache.wiki.api.exceptions.PluginException;
025import org.apache.wiki.api.plugin.WikiPlugin;
026import 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 */
042public 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}