Any glaring errors so far?

[PHP John]

This is my first class, and I would like to know if there are any glaring errors that you can see. (it's not complete, either )

<?php
  class calendarMonth()
  {
    //  m - month; i.e. "01" to "12"
    //  M - month, textual, 3 letters; e.g. "Jan"
    //  F - month, textual, long; e.g. "January"
    //  Y - year, 4 digits; e.g. "1999"
    //  D - day of the week, textual, 3 letters; e.g. "Fri"
    //  d - day of the month, 2 digits with leading zeros; i.e. "01" to "31"
    //  l (lowercase 'L') - day of the week, textual, long; e.g. "Friday"
    //  L - boolean for whether it is a leap year; i.e. "0" or "1"
    var $firstCell   = 0;
    var $thisDayDate = date("d");
    var $thisMonth;
    var $nextMonth;
    var $prevMonth;
    var $thisYear;
    var $nextYear;
    var $prevYear;
    var $monthTable = '';
    var $firstDay;
    var $thisMonthName;
    var $newRow = 0;
    var $dayCellHeight;
    var $titleCellHeight;
    var $tableWidth;
    var $colWidth;
    var $tableBorder;
    var $tableBorder;
    var $cellPadding;
    var $cellSpacing;
    var $cellBorder;
    var $tableBGColor;
    var $cellBGColor;
    var $borderColor;
    var $monthDaysArray = array("January"   => 31,
                                "February"  => 28,
                                "March"     => 31,
                                "April"     => 30,
                                "May"       => 31,
                                "June"      => 30,
                                "July"      => 31,
                                "August"    => 31,
                                "September" => 30,
                                "October"   => 31,
                                "November"  => 30,
                                "December"  => 31);
    var $dayNumberArray = array("Sat" => 0,
                                "Sun" => 1,
                                "Mon" => 2,
                                "Tue" => 3,
                                "Wed" => 4,
                                "Thu" => 5,
                                "Fri" => 6);
    var $weekDayArray   = array("Saturday", "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday");
    function calendarMonth( $argsArray )
    {
      //$argsArray = func_get_args();
      define('DAYSPERWEEK', 7);
      $this->thisMonth       = isset($argsArray['month']) ? $argsArray['month'] : date("m");
      $this->nextMonth       = $thisMonth + 1;
      $this->prevMonth       = $thisMonth - 1;
      $this->thisYear        = isset($argsArray['year']) ? $argsArray['year'] : date("Y");
      $this->nextYear        = $thisYear + 1;
      $this->prevYear        = $thisYear - 1;
      $this->firstDay        = date("D", mktime(0, 0, 1, $thisMonth, 1, $thisYear));
      $this->thisMonthName   = date("F", mktime(0, 0, 1, $thisMonth, 1, $thisYear));
      $this->newRow          = 0;
      $this->dayCellHeight   = isset($argsArray['dateCellHeight'])    ? $argsArray['dateCellHeight']    : 60;
      $this->titleCellHeight = isset($argsArray['colHeadCellHeight']) ? $argsArray['colHeadCellHeight'] : 18;
      $this->tableWidth      = isset($argsArray['tableWidth'])        ? $argsArray['tableWidth']        : 750;
      $this->colWidth        = $tableWidth / DAYSPERWEEK;
      $this->tableBorder     = isset($argsArray['tableBorder'])       ? $argsArray['tableBorder']       : 4;
      $this->cellPadding     = isset($argsArray['cellPadding'])       ? $argsArray['cellPadding']       : 5;
      $this->cellSpacing     = isset($argsArray['cellSpacing'])       ? $argsArray['cellSpacing']       : 0;
      $this->cellBorder      = isset($argsArray['cellBorder'])        ? $argsArray['cellBorder']        : 1;
      $this->tableBGColor    = isset($argsArray['tableBGColor'])      ? $argsArray['tableBGColor']      : "#00FFFF";
      $this->cellBGColor     = isset($argsArray['cellBGColor'])       ? $argsArray['cellBGColor']       : "#0099FF";
      $this->borderColor     = isset($argsArray['borderColor'])       ? $argsArray['borderColor']       : "#000000";
      if(date("L", mktime(0, 0, 0, 1, 1, $nextYear)))
      {
        $this->monthDaysArray["February"] = 29;
      } //  End test for leap year
    } //  End calendarMonth constructor
    function setMonth( $month )
    {
      $this->thisMonth = $month;
      $this->nextMonth = $thisMonth + 1;
      $this->prevMonth = $thisMonth - 1;
    }
    function setYear( $year )
    {
      $this->thisYear = $year;
      $this->nextYear = $thisYear + 1;
      $this->prevYear = $thisYear - 1;
    }
    function setDayCellHeight( $color )
    {
      $this->dayCellColor = $color;
    }
    function setTitleCellHeight( $height )
    {
      $this->titleCellHeight = $height;
    }
    function setTableWidth( $width )
    {
      $this->tableWidth = $width;
    }
    function setTableBorder( $border )
    {
      $this->tableBorder = $border;
    }
    function setCellPadding( $padding )
    {
      $this->cellPadding = $padding;
    }
    function setCellSpacing( $spacing )
    {
      $this->cellSpacing = $spacing;
    }
    function setCellBorder( $border )
    {
      $this->cellBorder = $border;
    }
    function setTableBGColor( $color )
    {
      $this->tableBGColor = $color;
    }
    function setCellBGColor( $color )
    {
      $this->cellBGColor = $color;
    }
    function setBorderColor( $color )
    {
      $this->borderColor = $color;
    }
    function showArgs()
    { }
    function buildMonth( $month, $year )
    {
      if( isset( $month ))
        $this->setMonth( $month );
      if( isset( $year ))
        $this->setYear( $year );
      $this->monthTable = '<table width="'.$tableWidth.'" border="'.$tableBorder.'" cellpadding="'.$cellPadding.'" bordercolor="'.$borderColor.'" bgcolor="'.$tableBGColor.'" summary="Month display">
                      <tr bgcolor="'.$cellBGColor.'">
                        <td align="center">
                          ';
      if($nextMonth + 1 > 12)
      {
        $nextMonth = 1;
        $nextYear += 1;
      }
      else
      {
        $nextMonth +=  1;
      }
      if($prevMonth < 1)
      {
        $prevMonth = 12;
        $prevYear -= 1;
      }
      if($prevMonth >= date("m") || $prevYear > date("Y"))
      {
        $this->monthTable .= '<a href="'.$PHP_SELF.'?nextMonth='.$prevMonth.'&year='.$prevYear.'"><<</a>';
      }
      else
      {
        $this->monthTable .= '&nbsp;';
      }
      $this->monthTable .= '  <td align="center">
                          '.$thisMonthName.'
                        </td>
                        <td align="center">
                          <a href="'.$PHP_SELF.'?nextMonth='.$nextMonth.'&year='.$nextYear.'">>></a>
                        </td>
                        <td colspan="4" align="center">
                          &nbsp;
                        </td>
                      </tr>
                      ';
      for($i = 0; $i < DAYSPERWEEK; $i++)
      {
        $this->monthTable .= '<td height="'.$titleCellHeight.'" width="'.$colWidth.'">
                          <div align="center">'.$weekDayArray[$i].'</div>
                        </td>
                        ';
      }
      $this->monthTable .= '</tr>';
      $firstCell = $dayNumberArray[$firstDay];
      ++$firstCell;
      $this->monthTable .= '<tr valign="top">';
      for($blanks = 1; $blanks < $firstCell; $blanks++)
      {
        $this->monthTable .= '<td>
                        </td>
                       ';
        ++$newRow;
      }
      for($cell = 0; $cell < $monthDaysArray[$thisMonthName]; $cell++)
      {
        $monthdayNumberArray = $cell + 1;
        $this->monthTable .= '<td align="left" height="'.$dayCellHeight.'">
                       ';
        if($thisDayDate == $monthdayNumberArray)
        {
          $this->monthTable .= '<span class="todaysDate">'.$monthdayNumberArray.'</span>';
        }
        else
        {
          $this->monthTable .= $monthdayNumberArray;
        }
        $this->monthTable .= '</td>
                       ';
        ++$newRow;
        if($newRow == 7)
        {
          $this->monthTable .= '</tr>
                          <tr valign="top">
                          ';
          $newRow = 0;
        }
      }
      $this->monthTable .='     </tr>
                        </table>
                        ';
      return $this->monthTable;
    } //  End buildMonth function
  } //  End class calendarMonth
?>

[PHP John]

Do ALL variables inside a class need to be in this format: $this->var (without the $) ?

[torrent]

No. If the variable you are using is to become part of that object then you should
reference like: $this->foobar

If you are using a variable passed into one of the object's methods, which is then
no longer required after the function exits, then you do not need to reference that way.

Example:

class example
{
    var $foo;

    function example($bar)
    {
        $this->foo = $bar;
        $this->printMe();
    }

    function printMe()
    {
        print $this->foo;
        // note that $bar is no longer available here
    }
}

$test = new example('Hello'); 

[been]

I also think there are some 'problems' with your class:
First of all it tries to do a lot of things on the displaying side of things (the view), maybe it would be better to refactor that into a different class?
Secondly, The url's in the calender are hardcoded (which, I guess is the role of the view part of the component), in the sense that a link in the calender will always send request to the script that generated the calender month in the first place. This should pose no problem if you have a central script functioning as a sort of frontloader (you know, 'index.php?page=calender&command=viewMonth&y=2003&month=5'). But what if you have different scripts for different pages in your site? For example, suppose you want the current month displayed on the home page (home.php) and the calender days are links referring to another section in the site (events.php), using PHP_SELF isn't going to cut it then.
Also month names and day names are hardcoded, what if you want the class to be a part of multi-language website?

[Dr Livingston]

First this class is way to big

First of all, create a seperate class based on Templating of some kind to take care of displaying the calendar.

Second, create a class specifically to handle to dates and nothing else - including fetching $_GET values etc.

Then another class, which should extend the above class to act as overall control of calendar behaviours.

Nobody said designing OOP classes was easy - and it's not, if you want to do it properly

But you'll get there, have a look over at HarryF's phppatterns.com for more on designing OOP w/ PHP...

[PHP John]

Torrent, thanks for the points.

Been, good point about the multi-language capability.

Dr., I'll have a look-see at that link, but you can be sure that I'll be back to ask more questions! And post revisions to this class (and maybe its divisions!)