calendar class

[ws0x9]

General calendar class for apps. I'm a little worried that the way I find the number of weeks in the month isn't the best way. What do you think?

<?php

class calendar {

    //calendar construct
    //takes timestamp as arg.
    //if no timestamp it defaults to current
    function show_calendar($timestamp) {

        //if there is no timestamp give it now
        if(strlen($timestamp) == 0)
            $timestamp = time();

        $day_array = array("Sun","Mon","Tue","Wed","Thu","Fri","Sat");

        //numeral for day of week
        $start = date("w", mktime(0, 0, 0, date("m", $timestamp), 1, date("Y", $timestamp)));

        //days in the month
        $ending = date("t", $timestamp);

        //find the correct number of calendar weeks
        $cal_weeks = round(($start + $ending) / 7) + 1;

        //functions to format the date
        include_once("date_functions.php");

        echo "<table class=\"calendar\">";
            echo "<tr>";
                echo "<th colspan=\"" . count($day_array) . "\">";
                    echo "<a href=\"" . $_SERVER["SCRIPT_NAME"] . "?shift=back&timestamp=" . $timestamp . "\"><=</a>&nbsp;";
                    $cal_title = cal_title($timestamp);
                    echo $cal_title;
                    echo "&nbsp;<a href=\"" . $_SERVER["SCRIPT_NAME"] . "?shift=forward&timestamp=" . $timestamp . "\">=></a>";
                echo "</th>";
            echo "</tr>";
            echo "<tr>";
            for($i=0;$i<count($day_array);$i++) {
                echo "<th class=\"calendar\">";
                    echo $day_array[$i];
                echo "</th>";
            }

            //day number
            $x = 1;

            echo "</tr>";
            for($i = 0; $i < $cal_weeks; $i++) {
                echo "<tr>";
                    if($i == 0) {
                        for($j = 0; $j < 7; $j++) {
                            if($j < $start) {
                                echo "<td class=\"calendar\">";
                                echo "</td>";
                            }
                            else {
                                echo "<td class=\"calendar\"><a href=\"" . $_SERVER["SCRIPT_NAME"] . "?timestamp=" . mktime(0, 0, 0, date("M", $timestamp), $x, date("Y", $timestamp)) . "\" class=\"calendar\">";
                                    echo $x;
                                echo "</a></td>";
                                $x++;
                            }
                        }
                    }
                    if($i > 0 && $i < $cal_weeks - 1) {
                        for($j = 0; $j < 7; $j++) {
                            echo "<td class=\"calendar\"><a href=\"" . $_SERVER["SCRIPT_NAME"] . "?timestamp=" . mktime(0, 0, 0, date("M", $timestamp), $x, date("Y", $timestamp)) . "\" class=\"calendar\">";
                                echo $x;
                            echo "</a></td>";
                            $x++;                        
                        }
                    }
                    if($i == $cal_weeks - 1) {
                        for($j = 0; $j < 7; $j++) {
                            if($x > $ending) {
                                echo "<td class=\"calendar\">";
                                echo "</td>";
                            }
                            else {
                                echo "<td class=\"calendar\"><a href=\"" . $_SERVER["SCRIPT_NAME"] . "?timestamp=" . mktime(0, 0, 0, date("M", $timestamp), $x, date("Y", $timestamp)) . "\" class=\"calendar\">";
                                    echo $x;
                                echo "</a></td>";
                                $x++;
                            }                        
                        }
                    }
                echo "</tr>";
            }
        echo "</table>";

    }

    //shifts back and forth from month to month
    //takes the action as the arg
    function shift($action, $timestamp) {
        if(strcmp($action, "back") == 0) {
            $timestamp = mktime(0, 0, 0, date("m", $timestamp) - 1, 1, date("Y", $timestamp));
        }
        if(strcmp($action, "forward") == 0) {
            $timestamp = mktime(0, 0, 0, date("m", $timestamp) + 1, 1, date("Y", $timestamp));
        }
        else
            $timestamp = $timestamp;
        return $timestamp;
    }
    //returns the new timestamp

}

$c1 = new calendar();
if($_GET["shift"])
    $timestamp = $c1->shift($_GET["shift"], $_GET["timestamp"]);

$c1->show_calendar($timestamp);
?> 

[Moonglobe]

in show_calendar, you might want to set $timestamp to a default value, i.e:

function show_calendar($timestamp = '') {//..

[intenz]

Nice class.

[ws0x9]

Thanks, and that is a good idea to give it a default value for the timestamp right of the bat.

[crimaniak]

fully unusable class in real cituation. presentation hard-coded, days of week hard-coded, no cell-drawing callback or procedure to override.