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 org.apache.wiki.api.core.Context;
022import org.apache.wiki.api.exceptions.PluginException;
023import org.apache.wiki.api.plugin.Plugin;
024import org.apache.wiki.util.TextUtil;
025
026import java.util.Map;
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 implements Plugin {
043    // private static Logger log = LogManager.getLogger( Counter.class );
044
045    /** Parameter name for setting the name.  Value is <tt>{@value}</tt>. */
046    public static final String  PARAM_NAME          = "name";
047    /** Parameter name for setting the increment.  Value is <tt>{@value}</tt>. */
048    public static final String  PARAM_INCREMENT     = "increment";
049    /** Parameter name for setting the showResult.  Value is <tt>{@value}</tt>. */
050    public static final String  PARAM_SHOW_RESULT   = "showResult";
051    /** Parameter name for setting the start.  Value is <tt>{@value}</tt>. */
052    public static final String  PARAM_START         = "start";
053    public static final String  DEFAULT_NAME        = "counter";
054    private static final int     DEFAULT_INCREMENT   = 1;
055    private static final boolean DEFAULT_SHOW_RESULT = true;
056
057    /**
058     *  {@inheritDoc}
059     */
060    @Override
061    public String execute( final Context context, final Map< String, String > params ) throws PluginException {
062        //  First, determine which kind of name we use to store in the WikiContext.
063        String  countername = params.get(  PARAM_NAME);
064
065        if( countername == null ) {
066            countername = DEFAULT_NAME;
067        } else {
068            countername = DEFAULT_NAME+"-"+countername;
069        }
070
071        //  Fetch the old value
072        Integer val = context.getVariable( countername );
073        if( val == null ) {
074            val = 0;
075        }
076        
077        //  Check if we need to reset this
078        final String start = params.get( PARAM_START );
079        if( start != null ) {
080            val = Integer.parseInt( start );
081        } else {
082            //  Determine how much to increment
083            final String incrementObj = params.get( PARAM_INCREMENT );
084            int increment = DEFAULT_INCREMENT;
085            if( incrementObj != null ) {
086                increment = Integer.parseInt( incrementObj );
087            }
088
089            val = val + increment;
090        }
091        
092        context.setVariable( countername, val );
093
094        // check if we want to hide the result (just count, don't show result on the page
095        final String showObj = params.get(PARAM_SHOW_RESULT);
096        boolean show = DEFAULT_SHOW_RESULT;
097        if( showObj != null ) {
098            show = TextUtil.isPositive( showObj );
099        }
100        
101        if( show ) {
102            return val.toString();
103        } 
104       
105        return "";
106    }
107
108}