Libraries, directories, short lists, and glue

This morning I spoke with Richard Wallis, who is the technical development manager for Talis, one of the OPAC (online public access catalog) vendors whose clients' libraries are accessible using LibraryLookup. Talis is one of a handful of OPACs for which I'd built static lists of bookmarklets, based on information I'd gathered from libdex.com. Maintaining those long lists was problematic, though, as maintaining long lists always is. So last month I deprecated them in favor of the bookmarklet generator.

In theory, that meant I only needed to maintain a short list of rules, which are just URL patterns. Using these, folks could plug in the domain names of their OPACs and create bookmarklets on the fly.

In practice, of course, there are always exceptions to rules. By adding parameters to the URL patterns I was able to handle some of the exceptions, but that made things more complicated for folks using the bookmarklet generator.

So I was delighted to learn that Talis now offers a service that hides that complexity behind a simple interface. Here are some examples:

opacs.talis.com/resolver/lookup.opacs?sid=redirect:boroughofpoole.com&isbn=0747255989

opacs.talis.com/resolver/lookup.opacs?sid=redirect:port.ac.uk&atitle=MFC%20Programming

In each case, a general query is resolved to the specific syntax required by the Talis OPAC whose domain name appears in the query. Nice! The ISBN-style query, as seen in the first example above, is now incorporated into the LibraryLookup bookmarklet generator. At panlibus, the Talis blog, you can read about another use of the Talis resolver by RedLightGreen.

If other OPAC vendors decide to offer similar resolvers -- and I hope they do -- we'd get to see an interesting case study in the federation of decentralized directories. Let's assume that nobody will agree on a centralized authority or query syntax. Even so, the matrix gets a whole lot simpler. Instead of tens of OPAC vendors times hundreds of implementations, we're down to just the tens. One, of course, is ideal, but rarely achievable. That's OK. Any time the folks living in the glue layer get to work with shorter lists, it's a huge win.


Former URL: http://weblog.infoworld.com/udell/2005/05/27.html#a1239