in reply to Re^3: CGI javascript AJAX - progress in real time on a web page.
in thread CGI javascript AJAX - progress in real time on a web page.

Hi, Well, I decided to go for the server push method, because :
  1. it seemed to work and was simple to do
  2. er, no second reason ...
This is what I did, I created an empty div, then filled it with more little div boxes for each thing in the loop. Also I put a span in for a textual N / M status. All on the fly, using JavaScript innerHtml to change elements on the page, just by sending the JavaScript command to the browser.

Seemed to work!

Note that I used =+ to add innerHTML boxes to existing boxes.

main_prog.cgi :
print header; ... etc ... # Print a div box with a span element to fill in with later JavaScript + commands. # print "<div id=\"Progress\" class=\"box_div\"> " . " <i>Progress on things </i> : " . " <span id=\"meter\"></span> " . "</div>\n"; ... # Loop the loop # my $max_things = scalar (@things); my $thing_index = 0; foreach my $thing (@things) { $thing_index++; ... # Print the current thing into the span meter. # print <<_EOT_; <script language=JavaScript type=text/javascript><!-- document.getElementById('meter').innerHTML ='$thing_index of $max_ +things'; //--></script> _EOT_ # Do the things ... ... if ($status eq "excellent") { # Add a small div box with the thing and a tick # image to the main div box - its all floated # left so will fill up nicely. # print <<_EOT_; <script language=JavaScript type=text/javascript><!-- document.getElementById('Progress').innerHTML+='<div class=\"div_o +k\">Thing $thing_index is excellent<img src=/img/tick.png width=\"10\ +" height=\"10\ "></div>'; //--></script> _EOT_ } else { <script language=JavaScript type=text/javascript><!-- document.getElementById('Progress').innerHTML+='<div class=\"div_n +otok\">Thing $thing_index is v. bad<img src=/img/cross.png width=\"10 +\" height=\"10\ "></div>'; //--></script> _EOT_ } # endif excellent } # end foreach thing

The CSS was :
div.box_div { border: thin solid #000000; padding:5px; margin:9px; color:#0088FF; width:75%; float:left; } div.div_ok { border: thin solid #0088FF; padding:2px; margin:2px; color:#0088FF; float:left; } div.div_notok { border: thin solid #FF0000; padding:2px; margin:2px; color:#FF0000; float:left; } </style>
So it seems the trick was just to send JavaScript commands to the browser from the Perl CGI.

Not ideal, but seemed to work for IE6 and FF3. Ymmv etc ;)

Hope that's useful for someone.