Browser Console Error

Question

In regards to answer below i have the following error in my browser console

The error is on this line according to the browser console

Uncaught TypeError: Cannot set property 'onclick' of nullcal.php:26 (anonymous function)

When the a date is clicked other than in the january, april, novemeber the form doesnt opens.

the code on like 26 is from the console browser is

document.getElementById('trigger0').onclick = function()     
{showForm()};document.getElementById('trigger1').onclick = function()    
{showForm()};document.getElementById('trigger2').onclick = function() 
{showForm()};document.getElementById('trigger3').onclick = function() 
{showForm()};document.getElementById('trigger4').onclick = function() 
{showForm()};document.getElementById('trigger5').onclick = function() 
{showForm()};document.getElementById('trigger6').onclick = function() 
{showForm()};document.getElementById('trigger7').onclick = function()    
{showForm()};document.getElementById('trigger8').onclick = function() 
{showForm()};document.getElementById('trigger9').onclick = function() 
{showForm()};document.getElementById('trigger10').onclick = function() 
{showForm()};document.getElementById('trigger11').onclick = function() 
{showForm()};document.getElementById('trigger12').onclick = function() 
{showForm()};document.getElementById('trigger13').onclick = function() 
{showForm()};document.getElementById('trigger14').onclick = function() 
{showForm()};document.getElementById('trigger15').onclick = function() 
{showForm()};document.getElementById('trigger16').onclick = function() 
{showForm()};document.getElementById('trigger17').onclick = function() 
{showForm()};document.getElementById('trigger18').onclick = function() 
{showForm()};document.getElementById('trigger19').onclick = function() 
{showForm()};document.getElementById('trigger20').onclick = function() 
{showForm()};document.getElementById('trigger21').onclick = function() 
{showForm()};document.getElementById('trigger22').onclick = function() 
{showForm()};document.getElementById('trigger23').onclick = function() 
{showForm()};document.getElementById('trigger24').onclick = function() 
{showForm()};document.getElementById('trigger25').onclick = function() 
{showForm()};document.getElementById('trigger26').onclick = function() 
{showForm()};document.getElementById('trigger27').onclick = function() 
{showForm()};document.getElementById('trigger28').onclick = function() 
{showForm()};document.getElementById('trigger29').onclick = function() 
{showForm()};document.getElementById('trigger30').onclick = function() 
{showForm()};document.getElementById('trigger31').onclick = function()   
{showForm()};document.getElementById('trigger32').onclick = function()  
{showForm()};document.getElementById('trigger33').onclick = function()    
{showForm()};document.getElementById('trigger34').onclick = function()     
{showForm()};   function showForm(){

The code it relates to is:

$timestamp = mktime(0,0,0,$cMonth,1,$cYear);
$maxday = date("t",$timestamp);
$thismonth = getdate ($timestamp);
$startday = $thismonth['wday'];
$today = getdate();

for ($i=0; $i<($maxday+$startday); $i++) {

if(($i % 7) == 0 ) echo "<tr> ";

if($i < $startday) echo "<td></td> ";

  else echo "<td align='center' valign='middle' height='20px'><a href='#'    
 id='trigger" . $i . "'>". ($i - $startday + 1) . "</a></td>";  

  $jsEvent[] = "document.getElementById('trigger" . $i . "').onclick =     
 function() {showForm()};";

  if(($i % 7) == 6 ) echo "</tr> ";
  }
  ?>

the javascript code

 <script type="text/javascript">
 <?php foreach($jsEvent as $event){
        echo $event;
     } ?>
 function showForm(){
     document.getElementById('timeslots').style.display="block";
 };
 </script>

Answer 1

You can use javascript for that. You can use onClick="" to trigger a js function that hides / shows your form.

<script type="text/javascript">
   <?php foreach($jsEvent as $event){
            echo $event;
         } ?>
   function showForm(){
         document.getElementById('timeslots').style.display="block";
    };
</script>

Then change

<table width='400' border='2' cellpadding='2' cellspacing='2' id='timeslots'
  style="visibility:invisible"'>

to

<table width='400' border='2' cellpadding='2' cellspacing='2' id='timeslots'
  style="display:none;"'>

Also change this:

<td align='center' valign='middle' height='20px'><a href='#'>". ($i - $startday + 1) . "</a></td>

to this:

<td align='center' valign='middle' height='20px'><a href='#' id='trigger" . $i . "'>". ($i - $startday + 1) . "</a></td>

Remember that "editform" is only a suggested ID and needs to match the ID of the trigger / date you are using.

I have tried and searched high and low and I am unable to come up with another soloution, Replace your for loop (the for and everything in it) with the code below

for ($i=0; $i<($maxday+$startday); $i++) {

if(($i % 7) == 0 ){
 echo "<tr> ";
}

if($i < $startday){
 echo "<td></td> ";
} else{
 $jsEvent[] = "document.getElementById('trigger" . $i . "').onclick =     
 function() {showForm()};" . PHP_EOL;     

 echo "<td align='center' valign='middle' height='20px'><a href='#'    
 id='trigger" . $i . "'>". ($i - $startday + 1) . "</a></td>"; 
}



  if(($i % 7) == 6 ){
      echo "</tr> ";
 }
  }

The JS function could be alot more advanced, like checking or hiding other opened forms, this is just a simple JS function that displays a single form by ID

UPDATE Updated my answer according to information from comments :), now you just need to change the ID of the first document.GetelemtentByID to match the id of the "link/text" you want to trigger the function.

Answer 2

I didn't read your code and I assume the the php code mechanism works for creating the calendar, what you need is to put your form in a <div></div> with style attribute and store some CSS in it that makes your division invisible which is display:none; or visibility:hidden. also you can set these setting in a class attribute and put your styles in external css. like this:

<div style="display:none;" id="calendar"><?php #your php code here ?></div>

then, you need to put a simple Java script to on the object you want to make div visible like this:

<a onclick="document.getElementById('calendar').style.display='block'"> click me to show calendar </a>