HTML and CSS Reference
In-Depth Information
The browser plays the first segment while downloading the second, then
third, then fourth, and so on.
13.2.4. Combining Refresh with Other HTTP Header Fields
You can have your client-pull dynamic documents perform some neat
tricks by combining the effects of the
Refresh
field with other HTTP head-
er fields. One combination that is particularly useful is
Refresh
with a
Redirect
field.
The
Redirect
field lets the server tell the browser to retrieve the reques-
ted document elsewhere at the field's accompanying URL value. The cli-
ent browser automatically redirects its request to the new URL and gets
the document from the new location, usually without telling the user.
We retrieve redirected documents all the time and may never notice.
The most common cause for redirection is when someone moves an
HTML document collection to a new directory or to a new server. As a
courtesy, the webmaster programs the original host server to send an
HTTP header field containing the
Redirect
field and new URL (without
a document body) to any and all browsers that request the document
from the original location. That way, the new document location is trans-
parent to users, and they won't have to reset their browser bookmarks.
But sometimes you want the users to reset their bookmarks to the
new location, because the old one won't be redirecting browsers forever
(perhaps because it's being taken out of service). One way to notify
users of the new location is to have the redirection URL point to some
HTML document other than the home page of the new collection that
contains a message about the new location. Once noted, users then
take a "Continue" hyperlink to the new home page location and set their
bookmarks accordingly.
By combining the
Redirect
and
Refresh
fields, you can make that notific-
ation screen automatically move to the new home page. If the browser
receives an HTTP header with both fields, it honors both; it immediately
fetches the redirected URL and displays it, and it sets the refresh timer
