Re: Automatic Page Updates

Marc Salomon (
Tue, 10 Jan 1995 23:07:50 +0100

|>Is there any way in HTTP for a Server to automatically update a page
|>without requiring the user of the client to click on anything?

|Currently no. HTTP is connectionless, and that makes it hard to
|do things after a transaction is completed.

Except perform another transaction :)

The problem is that the data change on the server side and there is no
way in the current HTTP model for the server to contact a client to
inform them of this.

A solution that would be within the http model would be for the server to
inform the client that the content of this document changes rapidly and a
interval for refreshed. Something like:

C: GET /stock_quote.html HTTP/1.1
S: HTTP/1.1 200 OK
Content-type: text/html
-->Refresh: <time_interval>
Last-modified: Wednesday, 07-Dec-94 22:03:38 GMT
Expires: Wednesday, 07-Dec-94 22:03:39 GMT
Content-length: 1721

This would allow the client to set a timer and perform a GET on the URL
every time_interval so you would have the perception of a dynamically
updated document. The updates would be dependent on the alarm clock, of
course, instead of any real change in the content of the document, but I
think its the closest you are going to get under the current scheme.