Search/Retrieval via URL (SRU) is a specification for searching resources that relies on standard Web technology (HTTP, XML) for its implementation. Evergreen 1.4 supports basic SRU access through the /opac/extras/sru service defined in the Apache eg_vhost.conf
configuration file and implemented in the sru_search() method in Open-ILS/src/perlmods/lib/OpenILS/WWW/SuperCat.pm.
NOTE: This documentation is also available in the Evergreen documentation at http://libdog.mohawkcollege.ca/evergreen_documentation/1.6/draft/html/. In github: http://github.com/rsoulliere/Evergreen-DocBook/blob/master/1.6/admin/z3950.xml.
yaz-client is installed as a part of Index Data's YAZ software. Recent versions include support for querying SRU servers. Evergreen has shipped an SRU configuration that works out of the box since Evergreen 1.4. To search Evergreen with yaz-client, choose the GET query method and issue the find
command. In the following example, we connect to the Evergreen test server "dev.gapines.org"; substitute this hostname with your own Evergreen server hostname:
$ yaz-client http://dev.gapines.org/opac/extras/sru Z> sru GET 1.1 Z> find hemingway
If your database has records that match that term, you will get the corresponding MARCXML records in your response from yaz-client.
Here's what the SRU request looks like as sent to the Evergreen web server:
GET /opac/extras/sru?version=1.1&operation=searchRetrieve&query=hemingway&maximumRecords=0
You can see what the response looks like by hitting the same URL in your Web browser: http://dev.gapines.org/opac/extras/sru?version=1.1&operation=searchRetrieve&query=hemingway&maximumRecords=0
Evergreen supports some CQL index-sets for advanced queries such as a subset of Dublin Core (DC) elements. Those DC elements that are supported map to Evergreen default indexes as follows:
DC element | Evergreen index |
---|---|
title | title |
creator | author |
contributor | author |
publisher | keyword |
subject | subject |
identifier | keyword |
type | none |
format | none |
language | lang |
Here are a few examples of SRU searches against some of these indexes:
Prerequisite: You must have Evergreen's SRU server running before you can enable Z39.50 server support.
This support uses an Z39.50-to-SRU translator service supplied by the Net::Z3950::Simple2ZOOM Perl module to enable Evergreen to act as a Z39.50 server. You can run the Z39.50 server on a different machine; it just needs to be able to connect to the Evergreen SRU server.
sudo cpan Net::Z3950::Simple2ZOOM
)dgo.conf
for our example:<client> <database name="gapines"> <zurl>http://dev.gapines.org/opac/extras/sru</zurl> <option name="sru">get</option> <charset>marc-8</charset> <search> <querytype>cql</querytype> <map use="4"><index>eg.title</index></map> <map use="7"><index>eg.keyword</index></map> <map use="8"><index>eg.keyword</index></map> <map use="21"><index>eg.subject</index></map> <map use="1003"><index>eg.author</index></map> <map use="1018"><index>eg.publisher</index></map> <map use="1035"><index>eg.keyword</index></map> <map use="1016"><index>eg.keyword</index></map> </search> </database> </client>
You can have multiple <database> sections in a single file, each pointing to a different scope of your consortium. The name attribute on the <database> element is used in your Z39.50 connection string to name the database. The <zurl> element must point to http://hostname/opac/extras/sru
. As of Evergreen 1.6, you can append an optional organization unit shortname for search scoping purposes, and you can also append /holdings if you want to expose the holdings for any returned records. So your zurl could be http://dev.gapines.org/opac/extras/sru/BR1/holdings
to limit the search scope to BR1 and its children, and to expose its holdings.
<database name="egin"> <zurl>http://evergreen.lib.in.us/opac/extras/sru/</zurl> <option name="sru">get</option> <charset>marc-8</charset> <search> <querytype>cql</querytype> <map use="4"><index>eg.title</index></map> <map use="7"><index>eg.isbn</index></map> <map use="8"><index>eg.issn</index></map> <map use="21"><index>eg.subject</index></map> <map use="1003"><index>eg.author</index></map> <map use="1018"><index>eg.publisher</index></map> <map use="1035"><index>eg.keyword</index></map> <map use="1016"><index>eg.keyword</index></map> </search> </database>
xml2marc-yaz.cfg
:<yazgfs> <server id="server1"> <retrievalinfo> <retrieval syntax="xml"/> <retrieval syntax="marc21"> <backend syntax="xml"> <marc inputformat="xml" outputformat="marc" inputcharset="utf-8" outputcharset="marc-8"/> </backend> </retrieval> </retrievalinfo> </server> </yazgfs>
simple2zoom -c dgo.conf -- -f xml2marc-yaz.cfg localhost:2210 dev.gapines.org:210 &
To test the Z39.50 server, we can use yaz-client again:
yaz-client Z> open localhost:2210/gapines Connecting...OK. Sent initrequest. Connection accepted by v3 target. ID : 81/81 Name : Simple2ZOOM Universal Gateway/GFS/YAZ Version: 1.03/1.128/3.0.34 Options: search present delSet triggerResourceCtrl scan sort namedResultSets Elapsed: 0.010718 Z> format xml Z> find "dc.title=zone and dc.author=king" Sent searchRequest. Received SearchResponse. Search was a success. Number of hits: 0, setno 4 records returned: 0 Elapsed: 0.611432 Z> find "dead zone" Sent searchRequest. Received SearchResponse. Search was a success. Number of hits: 4, setno 5 records returned: 0 Elapsed: 1.555461 Z> show 1 Sent presentRequest (1+1). Records: 1 []Record type: XML <record xmlns:... (rest of record deliberately truncated)