* @input                string   $calendarname  optional: prefix for the calendar pages to be created - Must be a CamelCase word;
 *                                default: WikiName from the user

define ('USER_NAME',$this->GetUserName());
define ('BASE_URL',$this->config['base_url']);  

$calendarname   = USER_NAME;

$uCalendarname = $vars['calendarname'];
if ($uCalendarname) $calendarname = $uCalendarname;
//ToDo: check that it is a CamelCase word

Old:
// handle markup for current day or any other day
                $calday = sprintf('%4d:%02d:%02d',$year,$month,$day);
                if ($calday == $today)
                {
                        echo '                <td title="'.TODAY.'" class="currentday">'.$day."</td>\n";
                }
                else
                {
                        echo '                <td>'.$day."</td>\n";
                }
                // end week row

New:
// handle markup for current day or any other day
                        $calday = sprintf('%4d:%02d:%02d',$year,$month,$day);
               $pagename = sprintf('%s%4d%02d%02d', $calendarname,$year,$month,$day);
               if ($this->ExistsPage($pagename))
               {
               $pagename = BASE_URL.$pagename;
               $dayclass = '"created"';
               }
               else
               {
               $pagename = sprintf('%s%s/edit', BASE_URL,$pagename);
               $dayclass = '"new"';
               }   
                        if ($calday == $today)
                       {
                                echo '                <td title="'.TODAY.'" class="currentday">'.'<a href="'.$pagename.'" class='.$dayclass.'>'.$day."</a></td>\n";
                       }
                       else
                       {
                                echo '                <td>'.'<a href="'.$pagename.'" class='.$dayclass.'>'.$day."</a></td>\n";
                       }
                       // end week row

<?php
/**
 * Display a calendar face for a specified or the current month.
 *
 * Specifying a month and/or year in the action itself results in a "static" calendar face without
 * navigation; conversely, providing no parameters in the action results in a calendar face with
 * navigation links to previous, current and next month, with URL parameters determining which
 * month is shown (with the current month as default).
 *
 * You can have one "dynamic" (navigable) calendar on a page (multiple ones would just be the same)
 * and any number of "static" calendars.
 *
 * The current date (if visible) gets a special class to allow a different styling with CSS.
 *
 * Credit:
 * This action was inspired mainly by the "Calendar Menu" code written by
 * {@link http://www.blazonry.com/about.php Marcus Kazmierczak}
 * (© 1998-2002 Astonish Inc.) which we traced back as being the ultimate origin of this code
 * although our starting point was actually a (probably second-hand) variant found on the web which
 * did not contain any attribution.
 * However, not much of the original code is left in this version. Nevertheless, credit to
 * Marcus Kazmierczak for the original that inspired this, however indirectly: Thanks!
 *
 * @package                Actions
 * @subpackage        Date and Time
 * @name                Calendar
 *
 * @author                {@link http://wikka.jsnx.com/GmBowen GmBowen} (first draft)
 * @author                {@link http://wikka.jsnx.com/JavaWoman JavaWoman} (more modifications)
 * @version                0.8
 * @since                Wikka 1.1.6.0
 *
 * @input                integer  $year  optional: 4-digit year of the month to be displayed;
 *                                default: current year
 *                                the default can be overridden by providing a URL parameter 'year'
 * @input                integer  $month  optional: number of month (1 or 2 digits) to be displayed;
 *                                default: current month
 *                                the default can be overridden by providing a URL parameter 'month'
 * @input                string   $calendarname  optional: prefix for the calendar pages to be created - Must be a CamelCase word;
 *                                default: WikiName from the user
 * @output                data table for specified or current month
 *
 * @todo                - take care we don't go over date limits for PHP with navigation links
 *                                - configurable first day of week
 */

// ***** CONSTANTS section *****
define('MIN_DATETIME', strtotime('1970-01-01 00:00:00 GMT'));                # earliest timestamp PHP can handle (Windows and some others - to be safe)
define('MAX_DATETIME', strtotime('2038-01-19 03:04:07 GMT'));                # latest timestamp PHP can handle
define('MIN_YEAR', date('Y',MIN_DATETIME));
define('MAX_YEAR', date('Y',MAX_DATETIME)-1);                                                # don't include partial January 2038
// not-quite-constants
$daysInMonth = array(31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);
define('CUR_YEAR', date('Y',mktime()));
define('CUR_MONTH', date('n',mktime()));
// format string for locale-specific month (%B) + 4-digit year (%Y) used for caption and title attributes
// NOTE: monthname is locale-specific but order of month and year may need to be switched: hence the double quotes!
define('LOC_MON_YEAR', "%B %Y");                                                                                                                                        # i18n
define('FMT_SUMMARY', "Calendar for %s");                                                                                                                        # i18n
define('TODAY', "today");    
define ('USER_NAME',$this->GetUserName());
define ('BASE_URL',$this->config['base_url']);                                                                                                                                                  # i18n
// ***** END CONSTANTS section *****

// ***** (ACTION) PARAMETERS Interface *****
// set parameter defaults: current year and month
$year        = CUR_YEAR;
$month        = CUR_MONTH;
$calendarname   = USER_NAME;

// get and interpret parameters
// 1) overrride defaults with parameters provided in URL (accept only valid values)
if (isset($_GET['year']))
{
        $uYear = (int)$_GET['year'];
        if ($uYear >= MIN_YEAR && $uYear <= MAX_YEAR) $year = $uYear;
}
if (isset($_GET['month']))
{
        $uMonth = (int)$_GET['month'];
        if ($uMonth >= 1 && $uMonth <= 12) $month = $uMonth;
}

$uCalendarname = $vars['calendarname'];
if ($uCalendarname) $calendarname = $uCalendarname;
//ToDo: check that it is a CamelCase word

// 2) override with parameters provided in action itself (accept only valid values)
$hasActionParams = FALSE;
if (is_array($vars))
{
        foreach ($vars as $param => $value)
        {
                switch ($param)
                {
                        case 'year':
                                $uYear = (int)trim($value);
                                if ($uYear >= MIN_YEAR && $uYear <= MAX_YEAR)
                                {
                                        $year = $uYear;
                                        $hasActionParams = TRUE;
                                }
                                break;
                        case 'month':
                                $uMonth = (int)trim($value);
                                if ($uMonth >= 1 && $uMonth <= 12)
                                {
                                        $month = $uMonth;
                                        $hasActionParams = TRUE;
                                }
                                break;
                }
        }
}
// ***** (ACTION) PARAMETERS Interface *****

// ***** DERIVED VARIABLES *****
// derive which weekday the first is on
$datemonthfirst = sprintf('%4d-%02d-%02d',$year,$month,1);
$firstwday = strftime('%w',strtotime($datemonthfirst));                                                                                                # i18n

// derive (locale-specific) caption text
$monthYear        = strftime(LOC_MON_YEAR,strtotime($datemonthfirst));                                                                        # i18n
$summary        = sprintf(FMT_SUMMARY, $monthYear);                                                                                                                # i18n

// derive last day of month
$lastmday = $daysInMonth[$month - 1];
if (2 == $month)                                                                                                        # correct for leap year if necessary
{
        if (1 == date('L',strtotime(sprintf('%4d-%02d-%02d',$year,1,1)))) $lastmday++;
}

// derive "today" to detect when to mark this up in the calendar face
$today = date("Y:m:d",mktime());

// build navigation variables - locale-specific (%B gets full month name)
// FIXME: @@@ take care we don't go over date limits for PHP
if (!$hasActionParams)
{
        // previous month
        $monthPrev        = ($month-1 < 1) ? 12 : $month-1;
        $yearPrev        = ($month-1 < 1) ? $year-1 : $year;
        $parPrev        = "month=$monthPrev&year=$yearPrev";
        $urlPrev        = $this->Href('', '', $parPrev);
        $titlePrev        = strftime(LOC_MON_YEAR,strtotime(sprintf('%4d-%02d-%02d',$yearPrev,$monthPrev,1)));# i18n
        // current month
        $parCur                = 'month='.CUR_MONTH.'&year='.CUR_YEAR;
        $urlCur                = $this->Href('', '', $parCur);
        $titleCur        = strftime(LOC_MON_YEAR,strtotime(sprintf('%4d-%02d-%02d',CUR_YEAR,CUR_MONTH,1)));        # i18n
        // next month
        $monthNext        = ($month+1 > 12) ? 1 : $month+1;
        $yearNext        = ($month+1 > 12) ? $year+1 : $year;
        $parNext        = "month=$monthNext&year=$yearNext";
        $urlNext        = $this->Href('', '', $parNext);
        $titleNext        = strftime(LOC_MON_YEAR,strtotime(sprintf('%4d-%02d-%02d',$yearNext,$monthNext,1)));# i18n
}

// build array with names of weekdays (locale-specific)
$tmpTime        = strtotime("this Sunday");                        # get a starting date that is a Sunday
$tmpDate        = date('d',$tmpTime);
$tmpMonth        = date('m',$tmpTime);
$tmpYear        = date('Y',$tmpTime);
for ($i=0; $i<=6; $i++)
{
        $aWeekdaysShort[$i]        = strftime('%a',mktime(0,0,0,$tmpMonth,$tmpDate+$i,$tmpYear));
        $aWeekdaysLong[$i]        = strftime('%A',mktime(0,0,0,$tmpMonth,$tmpDate+$i,$tmpYear));
}
// ***** END DERIVED VARIABLES *****

// ***** OUTPUT SECTION *****
?>

<table cellpadding="2" cellspacing="1" class="calendar" summary="<?php echo $summary;?>">
<caption><?php echo $monthYear;?></caption>
<thead>
        <tr>
<?php
for ($i=0; $i<=6; $i++)
{
?>
                <th scope="col" width="26" abbr="<?php echo $aWeekdaysLong[$i];?>"><?php echo $aWeekdaysShort[$i];?></th>
<?php
}
?>
        </tr>
</thead>
<tbody class="face">
<?php
        // start row for first week (if it doesn't start on Sunday)
        if ($firstwday > 0)
        {
                echo "        <tr>\n";
        }
        // fill start of first week with blank cells before start of month
        for ($i=1; $i<=$firstwday; $i++)
        {
                echo '                <td> </td>'."\n";
        }

        // loop through all the days of the month
        $day = 1;
        $wday = $firstwday;
        while ($day <= $lastmday)
        {
                // start week row
                if ($wday == 0)
                {
                        echo "        <tr>\n";
                }
                // handle markup for current day or any other day
                $calday = sprintf('%4d:%02d:%02d',$year,$month,$day);
                $pagename = sprintf('%s%4d%02d%02d', $calendarname,$year,$month,$day);
                if ($this->ExistsPage($pagename))
                {
                        $pagename = BASE_URL.$pagename;
                        $dayclass = '"created"';
                }
                else
                {
                        $pagename = sprintf('%s%s/edit', BASE_URL,$pagename);
                        $dayclass = '"new"';
                }  
                if ($calday == $today)
                {
                        echo '                <td title="'.TODAY.'" class="currentday">'.'<a href="'.$pagename.'" class='.$dayclass.'>'.$day."</a></td>\n";
                }
                else
                {
                        echo '                <td>'.'<a href="'.$pagename.'" class='.$dayclass.'>'.$day."</a></td>\n";
                }
                // end week row
                if ($wday == 6)
                {
                        echo "        </tr>\n";
                }
                // next day
                $wday = ++$wday % 7;
                $day++;

        }

        // fill week with blank cells after end of month
        if ($wday > 0)
        {
                for ($i=$wday; $i<=6; $i++)
                {
                        echo '                <td> </td>'."\n";
                }
        }
        // end row for last week
        if ($wday < 6)
        {
                echo "        </tr>\n";
        }
?>
</tbody>
<?php
// generate navigation only for calendar without (valid) action parameters!
// FIXME: @@@ take care we don't go over date limits for PHP
if ($hasActionParams === FALSE)
{
?>
<tbody class="calnav">
        <tr>
                <td colspan="3" align="left" class="prevmonth"><a href="<?php echo $urlPrev;?>" title="<?php echo $titlePrev;?>"><<</a></td>
                <td align="center" class="curmonth"><a href="<?php echo $urlCur;?>" title="<?php echo $titleCur;?>">=</a></td>
                <td colspan="3" align="right" class="nextmonth"><a href="<?php echo $urlNext;?>" title="<?php echo $titleNext;?>">>></a></td>
        </tr>
</tbody>
<?php
}
?>
</table>
<?php
// ***** END OUTPUT SECTION *****
?>