Updating page content using server data

Posted on 2002-07-08
Last Modified: 2010-05-18

I have a page in a frame that displays the status of a device.  I refresh the page every 3 seconds and use CGI script to get the status.  Most of the time the status does not change.

I would like to read the status variable from the server and update the page status only upon change.  I do not like the idea of a page refresh.

Can I use JavaScript for this?  How can I read info from server?

I know that I can use a Java applet to read the page and compare the last status with prior one.  If it changed then I'll ask the applet to reload the page (a frame).

What is the best way to accomplish what I need?  Which is: read data from server and display status change if needed.


Question by:akoifman
LVL 14

Expert Comment

ID: 7139725
You can do that using XMLHTTP, but you will have to trigger some check from browser side anyway, you cannot send request from the server to the client invoked by the server.

Author Comment

ID: 7140390

What is XMLHTTP?  IS this just XML over HTTP?  How do I trigger the client request?  Can I do this with JavaScipt?

LVL 22

Accepted Solution

CJ_S earned 67 total points
ID: 7140399
It retrieves HTTP through XML.

Here's a little sample:
<script language="VBScript">
Public Function GetHTML(url, sError)
on error resume next
     Set objXML = CreateObject("Microsoft.XMLHTTP") "GET", url, false
     Call objXML.send
     If(objXML.status<>200) Then
          GetHTML = sError
          GetHTML = objXML.responseText
     End If

     Set objXML = Nothing
End Function

sData = GetHTML("", "Unable to retrieve site")

Free Tool: Site Down Detector

Helpful to verify reports of your own downtime, or to double check a downed website you are trying to access.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

LVL 53

Expert Comment

ID: 7140819
Just put a hidden frame or iframe in the page and do the request to the server from there.  When the information changes, a little JAvaScript snippet in the hidden frame then updates the main page.

Does not require any server side support that is not already there.


Author Comment

ID: 7140890

You write:
>>Just put a hidden frame or iframe in the page and do the >>request to the server from there.

Do you mean by applet loading the page in the browser periodically, say every 3 seconds?  Will this keep the annoying reload bar at the bottom of the browser flashing?

LVL 53

Expert Comment

ID: 7141673
Yes the reload bar will flash if it is visible.

If that is annoying, then open the page in a new window with no status bar.

LVL 53

Expert Comment

ID: 7212815
This question has been abandoned. I will make a recommendation to the
moderators on its resolution in a week or two. I appreciate any comments
that would help me to make a recommendation.
   In the absence of responses, I may recommend DELETE unless it is clear
   to me that it has value as a PAQ.  Silence = you don't care

LVL 53

Expert Comment

ID: 7240534
It is time to clean this abandoned question up.  

I am putting it on a clean up list for CS.

split avner, CJ_S, and COBOLdinosaur


If anyone participating in the Q disagrees with the recommendation,
please leave a comment for the mods.


Expert Comment

ID: 7263483
Per recommendation, force-accepted.

CS Moderator

avner: points for you at
COBOLdinosaur: points for you at

Featured Post

Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Use these top 10 tips to master the art of email signature design. Create an email signature design that will easily wow recipients, promote your brand and highlight your professionalism.
This article explains how to prepare an HTML email signature template file containing dynamic placeholders for users' Azure AD data. Furthermore, it explains how to use this file to remotely set up a department-wide email signature policy in Office …
In this tutorial viewers will learn how add a scalable full-width header using CSS3. Create a new HTML document with an internal stylesheet. Set a tiled background.:  Create a new div and name it Header. Position it with position:absolute at the top…
In this tutorial viewers will learn how to style elements, such a divs, with a "drop shadow" effect using the CSS box-shadow property Start with a normal styled element, such as a div.: In the element's style, type the box shadow property: "box-shad…

808 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question