[Web4lib] How do news aggregators know that a user has already read an item

[John Fitzgibbon]

Hi,

We store library events in a database. Users can query a web site to
find out what is going on where. Classic ASP is used to retrieve
information from the database and display the results to the user.

This lends itself to RSS and now we are attempting to output the results
for each query as an RSS feed. The advantage of this is that a user will
never have to re-read an item or event that he or she has read about
previously.

This raises the question how do News Aggregators achieve the effect of
not displaying previously read items? When writing the XML code (which
is delivered via ASP) we were worried that we were leaving something
out. We did not identify each item in any way. We did not include a date
field, but yet, inexplicably, it seems to work.

Also, for further testing, can we make the News Aggregator treat all
items from this feed as un-read? Our News Aggregator of choice is
SharpReader.

John Fitzgibbon

p: 00 353 91 562471
f: 00 353 91 565039
w: http://www.galwaylibrary.ie 

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