port listen/send

  • Follow


Is JavaScript able to send/listen for data on a specific port?  I'm seeking 
a solution to real time data interaction with my web server that doesn't 
require refreshing the page.  I.e., a chat room, where the data can be 
broadcast from the server arbitrarily and displayed by the client 
browser(s).  To accomplish the data transmission can I use JS, or do I need 
to augment my client-side platform to something like Java, et al? 


0
Reply 1388 9/16/2005 7:50:57 PM

1388-2/HB wrote:

> Is JavaScript able to send/listen for data on a specific port?  I'm
> seeking a solution to real time data interaction with my web server that
> doesn't
> require refreshing the page.  I.e., a chat room, where the data can be
> broadcast from the server arbitrarily and displayed by the client
> browser(s).  To accomplish the data transmission can I use JS, or do I
> need to augment my client-side platform to something like Java, et al?

Hi,

Javascript is not suited/able to directly open sockets and such actions.
However, you can relatively easy accomplish the same functionality by 
incorperating a server into your application.
eg: JS can use a hidden frame to load/read info that comes from a server.
You can also use the XMLHTTPRequest-object to circumvent the hidden frame.

You need a serverside scriptinglanguage (like PHP) to produce information 
you want.

A rude setup would look something like this:
2 frames, 1 hidden. (named displayFrame and communicationFrame)
Let JS load another page in the hidden communicationFrame: getInfo.php

This page contains the following info:
<html>
 <body onLoad="sendInfo();">
  <script type="text/javascript">
   function sendInfo(){
    // The following info is produced dynamically on the server

    parent.frames.displayframe.receiveInfo("This text comes from some 
database or from some chatengine.");

   }
  </script>
 </body>
</html>


and in the displayframe you have a function receiveInfo that receives a 
string and does something with that.

Now write some logic that refreshes the hidden frame every 10 seconds or 
something like that.

I wrote application like this, it is fun, but the responsiveness is much 
lower than can be achieved using an applet and Java, because of all the 
overhead and loading.

Anyway: I hope this gets you going. :-)

Good luck!

Reagrds,
Erwin Moller
0
Reply Erwin 9/17/2005 7:37:29 AM


1 Replies
252 Views

(page loaded in 0.032 seconds)

Similiar Articles:













7/27/2012 2:29:19 PM


Reply: