Hi Folks,

I am new to the forum and therefore a short introduction. I am a Multimedia Artist and therefore my knowledge is partially first class and in other parts it is to cry over. Since I am heavily working on projects it seems always only time to deal with a specific problem rather than basic knowledge. Thus, sometimes might a question seem somewhat really rookielike.

So hi everybody

My specific problem at hand is as follows: For my own clients using a not multimedia related service, I created a calender system. Most of the calendar is completed but there is still a rather peculiar problem.

In case a person for example visits a Symposium lasting several days, the Symposium consisting of several workshops the calendar owner might light to visit, the calendar shall allow appointment collisions.

The appointments are in a mySQL database. The code to retreive the data is quite simple:

PHP Code:
       $query = mysql_query("SELECT * FROM $App 
                             WHERE userID LIKE '{$_SESSION['userID']}' 
                             AND appDateStart LIKE '$userTermin' ");

       $result = mysql_num_rows($query);       
       $felder = mysql_num_fields($query);

       if(! $query) {die("Fehler bei Query $query"); }


       for($i=0; $i<$result; $i++) {
           $data[$i] = mysql_fetch_array($query); 
The second part important to the problem is my CSS. It consists of


HTML Code:
    <style>

     #tag {
     position: relative;
     height: 400px;
     width: 450px;
     border: 1px solid #DDD;
     }

      #termins {
      font: 12px Arial;
      position: absolute;
      height: 400px;
      width: 350px;
      left: 55px;
      line-height: 16px;
}

#zeit {
      font: 12px Arial;
      position: absolute;
      height: 400px;
      width: 50px;
      line-height: 16px;
      }


</style>



<div id='tag'>

<div id='zeit'>
<b>Zeit</b> <br />
08:00 <br /> 
08:30 <br /> 
09:00 <br />
09:30 <br />
10:00 <br />
10:30 <br />
11:00 <br />
11:30 <br />
12:00 <br />
12:30 <br />
13:00 <br />
13:30 <br />
14:00 <br />
14:30 <br />
15:00 <br />
15:30 <br />
16:00 <br />
16:30 <br />
17:00 <br />
17:30 <br />
18:00 <br />
18:30 <br />
19:00 <br />
19:30 <br />
</div>

<div id='termins'>
       HERE ARE THE #termins DIVS 
       --> Each #termins IS ONE APPOINTMENT
</div>

The #termins are placed with absolute positioning as follows:

HTML Code:
<div id='terminx' style='position: absolute; border: 1px solid red; 
                   top: " . $_top[$i] . "px; left: " . $_left[$i] . "px; width: " . $_width[$i] . "px; 
                   height: " . $_height[$i] . "px; '>
The Variables are set as follows:

PHP Code:
             $round_numerator = 15;
             $_minuteStart[$i] = date('i', strtotime($data[$i]['appTimeStart']));

             $_StartMin[$i] = ( round ( $_minuteStart[$i] / $round_numerator ) * $round_numerator );


             if ($_StartMin[$i] == '00') { $_minitStart[$i] =  0; } 
             elseif ($_StartMin[$i] == '15') { $_minitStart[$i] =  8; }
             elseif ($_StartMin[$i] == '30') { $_minitStart[$i] = 16; }
             elseif ($_StartMin[$i] == '45') { $_minitStart[$i] = 24; }


             $_stunde[$i] = date('H', strtotime($data[$i]['appTimeStart']));
             $_top[$i] = 16 + ($_stunde[$i]-8)*32 + $_minitStart[$i];


          // --- BERECHNUNG HEIGHT --------------------------------------

             $_minuteEnd[$i] = date('i', strtotime($data[$i]['appTimeEnd']));
             $_EndMin = ( round ( $_minuteEnd[$i] / $round_numerator ) * $round_numerator );

             if ($_EndMin[$i] = 0) { $_minitEnd[$i] =  0; }
             elseif ($_EndMin[$i] = 15) { $_minitEnd[$i] =  8; }
             elseif ($_EndMin[$i] = 30) { $_minitEnd[$i] = 16; }
             elseif ($_EndMin[$i] = 45) { $_minitEnd[$i] = 24; }

             $_stundeEnd[$i] = date('H', strtotime($data[$i]['appTimeEnd']));
             $_endzeit[$i] = 16 + ($_stundeEnd[$i]-8)*32 + $_minitEnd[$i];

             $_height[$i] = $_endzeit[$i] - $_top[$i]; 
Until here, everything works perfect.

The heights are set, the top_position is placed exactly beneath the respective time. But the setting of $_width and the question of the collision is the problem.

How can I ask in PHP, which appointments collide? I tried already several if-variations, but it seems I will only get the message colliding with another one, but not the original message it is collding with.

I get several values: 9 collides with 1, 1 collides with 2, 2 collides with 9. In reality, all three collide. How can I ask for that?

When doing above solution, I need absolute control over the width and the placement ($_left) to avoid overlapping appointment views.

Has anyone another idea, how I could work here? I am open to any suggestions. Maybe, I am handling the baby from the wrong side. Any ideas or help is welcome.

Yours, Sunny