Fw: description language

----- Original Message ----- 

From: Ashley 
Sanders 

To: Ray Denenberg, 
Library of Congress 

Sent: Thursday, April 24, 2008 4:54 AM

Subject: Re: description language

Ray,

[You'll have to forward this to the search-ws list as 
I'm still not a 
member.]

> Could one of you volunteer to quickly 
draft up a document for discussion 
> that treats both SRU 1.2 and 
openSearch?

Here's a description for an SRU server.

<sws 
xmlns="http://copac.ac.uk/schemas/sws/v0.1">
  
<op>
   <request 
href="http://copac.ac.uk:3000/copac?operation=searchRetrieve&amp;version=1.1&amp;query={query}&amp;maximumRecords={maxItems}&amp;recordSchema=info:srw/schema/1/mods-v3.0">
    
<param name="query" semantics="cql"/>
    <param 
name="maxItems" value="25"/>
   </request>
   
<response>
    <set 
name="numberOfItems">
     <xpath 
select="/zs:searchRetrieveResponse/zs:numberOfRecords"
       
string-value="yes"/>
    </set>
    
<set name="items">
     <xpath 
select="//mods"/>
    </set>
   
</response>
  </op>
</sws>

In essence, to 
handle SRU, all you need to do is:

1. Construct a query (the hard bit) 
and insert it into a url.
2. Extract the records from the response (which is 
easy with
    an XPath.)

Describing SRU itself isn't 
hard. The hard bit is CQL. The Description 
Language doesn't try to describe 
CQL, it assumes the program that reads
the Description (and performs the 
operations described within it) knows
how to build a CQL query from the 
search terms provided to it.

My impression of OpenSearch (from what has 
been said on the list) is
that service providers are expected to provide the 
OpenSearch 
descriptions of their service. Whereas with the Search-WS 
Description
Language I would expect the users of the service to write their 
own
Description, or at least tailor a template provide by the 
service
provider to the specific requirements of the 
searcher.

Therefore I see no need to provide the various "fluff" 
that
makes it into an OpenSearch document; namely stuff 
like:

    <ShortName>
    
<Description>
    <Tags>
    
<Contact>
    <Developer>
    
<Attribution>
    
<SyndicationRight>
    
<AdultContent>
    <Language>

If any of 
that is wanted it can be put in an XML comment, or
maybe inserted into the 
Description under the OpenSearch
namespace.

Ashley.

-- 

Ashley 
Sanders               

Copac 
http://copac.ac.uk A Mimas service funded by 
JISC