[Umlaut-general] some new useful things in Umlaut

[Jonathan Rochkind]

So, writing your OPAC/ILS/whatever adapter to get physical and 
electronic items from it to display in Umlaut is kind of tricky. Because 
every system works differently, including what functions are available 
to you as a developer. But also including the cataloging metadata inside 
our systems, in all it's weird unpredictability which can vary in 
general tendencies from library to library.

One of the trickier parts is trying to prevent showing duplicate info 
from your catalog and SFX, if you have duplicate info in both. 
(Especially because SFX, unlike the catalog data, is capable of ruling a 
link out if the _particular_ article you want is not avaialable due to 
range restrictions, as well as providing a (theoretically) direct to 
item level link. So you always want to trust SFX when SFX has something 
to say about a given provider.)

Anyhow, one thing is that I encourage anyone trying to implement such an 
adapter to talk to me, I'm happy to talk. I know that Scot at NYU is 
well on the way to a working Xerxes implementation there, although for 
some reason he's been unable to post to this rubyforge listserv.  Also, 
I need to write some documentation/guide to this stuff, at least 
explaining what I've done for my Horizon.

But okay, what I actually want to tell you about. I have abstracted out 
one useful helper method, when you are able to get MARC from your 
ILS/OPAC/whatever.  See the lib/marc_helper.rb class.  If you have an 
array of ruby MARC objects, you can pass them to add_865_links, and it 
will pull out 856 links for you, figure out what the best label to use 
for them is, try to make sure they don't duplicate SFX-controlled 
functionality, de-dup _within_ that array of MARC (which is why the 
argument is an array instead of just calling it one-by-one), and then 
actually add them as Umlaut responses.  Oh, also try (imperfectly) to 
figure out if it's REALLY a full text link, or a ToC link etc.

So that should be a convenience. No doubt we'll find things in there 
that need to be tweaked to work for your particular environment, because 
this stuff is so tricky and our environments are so unpredictable. Just 
let me know, I'm happy to fix what needs fixin.

Another new thing, is that a new standard-ish key in the 
ServiceResponses, :match_reliability used for indicating given item on 
the page may apply to a different edition of the work cited.  I use this 
when looking up book info NOT by isbn/lccn/oclcnum, but doing an 
author/keyword search. There's no easy way to know if it's the same 
edition or not. So you can now put something in the response saying 
that's the case, and further supplying a short string describing what 
edition/version it IS (in :edition_str).  The current views then display 
this to the user, but I'm not sure if that should remain (or get more 
compact and require a click to actually 'open up' the info), or what, 
but it makes sense for it to be in the data for the view to use it how 
it will.

Jonathan