- From: Theo van Veen <Theo.vanVeen@kb.nl>
- Date: Mon, 22 Apr 2002 14:37:55 +0200
- To: <quinn@indexdata.dk>, <azaroth@liverpool.ac.uk>
- Cc: <echristi@usgs.gov>, <www-zig@w3.org>
The subject gradually changed from searching XML to retrieving XML. As far as it concerns retrieving XML why not do it the SRU/SRW way. There we also will have a limited number of recordSchemas and it would be preferable to keep the Z39.50-XML record schemas identical to the SRU/SRW record schemas. As far as it concerns sending stylesheets: when a client gets the XML it can do the XSLT translation itself. I do not see the need of sending the stylesheet. We have a SRU client that is a complete portal for distributed searching written in a few lines of XSL with some Javascript. It allows you to specify the stylesheet locally. With our SRU server you can specify the xsl as URI as parameter and do a local transformation with stylesheet from somewhere else. As far as it concerns searching. We have found that it is extremely powerful to index all end-nodes of XML trees in records. Each word is indexed twice: once as "any" and once with the tag-name of the end-node as access point. So regardless of the amount of nesting of tags <author>van veen</author> is always found as author. By this we loose information on the context and can not use XPATH for searching but I have a strong feeling that this is more an advantage than a disadvantage. We can however when records are retrieved. Theo >>> Sebastian Hammer <quinn@indexdata.dk> 22-04-02 13:49 >>> At 12:31 22-04-2002 +0100, Robert Sanderson wrote: > > Yes, this is a good notion. Actually, given a known initial schema, it > > makes sense for the client to submit an XSLT stylesheet to request a > > transformation of each result set record prior to shipment. In my mind, > > this is exactly equivalent to the use of Espec-1, only more powerful, and > > standardised to boot. > >Can't we do that now by giving a URI in elementSetNames which refers to an >XSLT style sheet, rather than dumping potentially very long stylesheets >dynamically at the server for every request? For retrieval purposes, >specifying a style sheet and specifying a schema for the record to be >returned in result in the same outcome -- you get the record in a certain >format. Giving the URI as opposed to shipping the StyleSheet is arguably a simplification, although it does force the Z39.50 server to act as a HTTP client, and it requires the stylesheet to be available somewhere public. But again, it makes no sense to give the server a stylesheet unless you also have a way of telling the server what schema you expect the data to be in *at the beginning* of the transformation. You gotta say: "I would like this data in Schema X and *THEN* apply stylesheet Y to it. Otherwise, you're always relying on the server to make data available in one specific schema." I think we need CompSpec for this... that allows you to give the schema. Then we just need a convention for using a stylesheet as an alternative to Espec-1. --Sebastian -- Sebastian Hammer, Index Data <http://www.indexdata.dk/> Ph: +45 3341 0100, Fax: +45 3341 0101
Received on Monday, 22 April 2002 08:39:26 UTC