new links

Jim Davis (davis@dri.cornell.edu)
Thu, 4 Mar 1993 13:15:10 -0500


I am coming to appreciate how XMosaic keeps track of which links I
have traversed in a session, (although I also don't like it to keep
track across sessions) and it makes me want even more.

It would be nice the browser could somehow show me which links were
new, where new might mean either
1) the anchor was not present in the document last time I saw it, or
2) the document on the other side of anchor has changed. Of course,
this is not easy!

The simplest way to achieve #1 is to have the client keep track, for
each document, of all the anchors in the document. This would of
course increase the size of the data the client needs to keep track
of.

We can reduce the size of this data for those documents which adopt a
uniform naming convention for anchors, e.g. all anchors are
sequentially numbered and numbers are never re-used. An alternative
would be to adopt the convention of annotating the anchor with the
time and date it was created, e.g. something like

<A HREF="http://wiretap.spy.com:70/clinton.phonebook"
ANCHOR-CREATED-BY = "Boris Badenoff"
ANCHOR-CREATED-DATE = "3 Mar 1993 12:00 est">

To achieve #2 is much harder, since, in general, a link has no way of
knowing when the target document has changed. But sometimes a partial
solution is better than nothing. A partial step would be to annotate
the link with the time and date that the target was modified, so that,
at least for those cases where you DO know the target has changed, the
client can notice that, e.g.

<A HREF="http://wiretap.spy.com:70/clinton.phonebook"
TARGET-MODIFIED-DATE = "5 Mar 1993 1:00 est">