This is a job for AJAX. Instead of using document.location to redirect to another page, what you need to do is:

  1. Create an XMLHttpRequest object.
  2. Use that object to make a request (i.e., invoke your perl cgi script).
  3. Define a response handler that will receive the output of your script and insert it into your page, you can create an empty div element to act as a placeholder for this.
  4. After handling each response, setup the next request (this is how you would loop through all your dates)

Here's a simple demo I had laying around that does something similar: 

<html>
<head>
<script type="text/javascript">

function createRequestObject() { 
  var req; 
  if (window.XMLHttpRequest) { // Firefox, Safari, Opera... 
    req = new XMLHttpRequest();  
  } else if (window.ActiveXObject) { // Internet Explorer 5+ 
    req = new ActiveXObject("Microsoft.XMLHTTP");  
  } else { 
    // error creating the request object, 
    // (maybe an old browser is being used?)
    alert('There was a problem creating the XMLHttpRequest object'); 
    req = '';
  }
  return req; 
} 
     
// Make the XMLHttpRequest object 
var http = createRequestObject(); 
sendRequest();
     
function sendRequest() { 
  // Open perl script for requests 
  var now = new Date();
  http.open('GET', 'http://' + document.domain +  '/cgi-bin/ajax/demo.
+pl?nocache='+now.getTime(), true); 
  http.onreadystatechange = handleResponse; 
  http.send(null); 
} 
     
function handleResponse() { 
  if(http.readyState == 4 && http.status == 200){ 
    var response = http.responseText; // Text returned FROM perl scrip
+t 
    if(response) { // UPDATE ajaxText content 
      document.getElementById("ajaxText").innerHTML = response; 
      setTimeout('sendRequest()', 5000); 
    }
  }
} 
</script>
</head>
<body>
<p>The message is...</p>
<div id="ajaxText" >Hello World!</div>
</body> </html>

[download]

This is just a demo. The demo.pl cgi script simply prints out a random text string: 

#!/usr/bin/perl
use strict;
print "content-type: text/html\n\n";

my @messages = (
  "This is message 1",
  "This is message 2",
  "This is message 3",
  "This is message 4",
  "This is message 5",
);

# print a random message
print @messages[rand @messages] , "\n";

[download]

The response handler calls this script every 5 seconds using setTimeout(). Note that I append the epoch time to the cgi script query string so that the browser won't simply cache the first response and use it over and over (that's a common ajax gotcha). When you view the html page in your browser, you should see the message change randomly every 5 seconds.

I hope that helps get you moving in the right direction. Good luck!

In reply to Re: How to simulate? by scorpio17
in thread How to simulate? by isi

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