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Re: Question on server-push
At 8:53 AM 1995-12-30, Mark Klein wrote:
>cl-http 51.1 has "server-push", which apparently allows you to periodically
>update a page on the client's browser on the server's initiative. Is it
>possible to update a WWW page just on a as-needed basis, e.g. when the data
>underlying the display has changed?
Presently, you can do this if you keep the connection to the client open by using
server push. This will replace all the output displayed on the browser.
Alternatively, you could use client pull and have the client poll
for changes with some periodicity. Combined with conditional get, the page would
remain unchanged if the server reports no modification since the last cilent access.
You would need to arrange for the expiration method on your exported URL object
to update the universal time it reports for last modification. You can do this by providing
an appropriate function as the :expiration argument for http:export-url.
JavaScript does or will provide a way to do this kind of callback.
Otherwise, you would ned to use some other means to alert the client that it needs to update
its display so that it can refetch the url.