[OAI-implementers] Clickable OAI BaseURLs!

[Young,Jeff]

(Warning! Currently, this has only been tested with Internet Explorer 6.0
with the security settings for "Access data sources across domains" set to
"enable" or "prompt".)
Wouldn't it be nice if OAI baseURLs resolved to something more interesting
than an XML "badVerb" error response (e.g.
http://scholar.lib.vt.edu/theses/OAI2/)? Well, now they can! Here is an OAI
repository baseURL to demonstrate:
http://alcme.oclc.org/xmlregistry/OAIHandler.
The best part is that any OAI repository can be made to work this way by
merely including an XSL stylesheet reference in their OAI responses. Users
of OAICat (including any DSpace installation) can configure their repository
by adding the following lines to their oaicat.properties file: 
OAIHandler.styleSheet=http://alcme.oclc.org/xmlregistry/baseURL.xsl
OAIHandler.renderForOldBrowsers=false
(Once the errol.oclc.org domain I mentioned in an earlier message has been
established and I work out a few bugs, this stylesheet will be moved to
http://errol.oclc.org/xmlregistry.oclc.org/cab/baseURL.xsl. Notice that this
form of the URL is actually an Extended ERRoL (introduced at
http://www.openarchives.org/pipermail/oai-implementers/2003-October/001087.h
tml). This Extended ERRoL can be used to refer to the stylesheet from an
instance document as though it was a static document, when in fact it is
being transparently ripped out of an OAI GetRecord response.) 
Other providers of OAI repository software can provide the same clickable
baseURL user interface by merely including a reference to this stylesheet in
their OAI responses. I also recommend that they have their code insert a
<description><toolkit> element, designed by Hussein Suleman, to their
Identify responses so that their software branding information will appear
in place of the OAICat brand in the demo display. Also include the standard
repository oai_branding elements in the Identify response to have them
appear in the display as well. (BTW, major work needs to be done to make the
Identify response frame in particular more attractive. It's on my list.)
Let me go back to Extended ERRoLs for a minute. Imagine I want to include a
citation in a paper I'm writing that refers to a document I found in an OAI
repository. Here is the ERRoL I could use:
http://alcme.oclc.org/errol/ERRoLResolver/xmlregistry.oclc.org/demo/ISBN/052
1555132 . If I want to refer to the document itself, I could add the POI
extension:
http://alcme.oclc.org/errol/ERRoLResolver/xmlregistry.oclc.org/demo/ISBN/052
1555132?POI, which would resolve to the first usable dc:identifier in the
oai_dc record. But again, keep in mind that the
http://alcme.oclc.org/errol/ERRoLResolver portion will become
http://errol.oclc.org/ as soon as our systems people create and configure
the new domain.)
Looking a little closer at the user interface for this last example, you
will notice the frame at the bottom left for this item in OSU's OSCAR
catalog. It was able to do this because of the ISBN it scraped from the
GetRecord response. If an ISBN isn't found, the list of available ERRoLs
will be displayed in its place. If you get the OPAC screen, but want to see
the list of ERRoLs, there is a button for it in the Identify frame. 
Right now, the display is hardcoded to use the OSU catalog, but I will be
working to make this configurable to other libraries soon. BTW, the list of
libraries that will be supported is an OAI repository itself. This feature
is a minor variation of an earlier project I worked on located here:
<http://alcme.oclc.org/bookmarks/>. What's also cool about this is that it
is based on the FRBR work done by OCLC's Chief Scientist Thom Hickey so that
it will include other ISBNs for the same "work" when it does the search.
Once this is configurable, you can contact me to have your favorite library
added to the list. 
Another feature is the ability for repositories to add service buttons in
the Identify pane that operate within the interface by including
<description><service> entries in the Identify response. For example, notice
the search button in the Identify frame of the display. 
I mentioned a new feature of ERRoLs this morning so that you can use a
repository level ERRoL (i.e. an ERRoL containing an explicit repository
identifier without an item identifier) as a replacement for an OAI baseURL.
This includes the ability to append OAI-PMH parameters. So, instead of
baseURL http://alcme.oclc.org/xmlregistry/OAIHandler, I can use
http://alcme.oclc.org/errol/ERRoLResolver/xmlregistry.oclc.org instead.
(Keep reminding yourselves that this URL will be much shorter when the
errol.oclc.org domain is established.) Not only are these repository level
ERRoLs shorter than most official baseURLs, but they are also much more
intuitive and convenient, especially when you want to bring up the clickable
baseURL user interface introduced here. Also remember that the ERRoL
alternative to the official baseURL feature will automatically work for any
repository identifier registered at UIUC.
Although the user interface is done with nothing more than an XSL
stylesheet, I request that people contact me to have features added rather
than copy it and make their own changes for awhile. This whole thing came to
me in a flash, so I still have lots of ideas for improvements, not to
mention cleaning up the messy bits from my rush to make this available. 
I look forward to your comments and suggestions. 
Enjoy!. 
Jeff


---
Jeffrey A. Young
Software Architect
Office of Research, Mail Code 710
OCLC Online Computer Library Center, Inc.
6565 Frantz Road
Dublin, OH   43017-3395
www.oclc.org

Voice:	614-764-4342
Voice:	800-848-5878, ext. 4342
Fax:	614-718-7477
Email:	jyoung@oclc.org