NAME

NAME
SRU - Search and Retrieval by URL

SYNOPSIS
## a simple CGI example

use SRU::Request;
use SRU::Response;

## create CGI object
my $cgi = CGI->new();

## create a SRU request object from the CGI object
my $request = SRU::Request->newFromCGI( $cgi );

## create a SRU response based from the request
my $response = SRU::Response->newFromRequest( $request );

if ( $response->type() eq 'explain' ) {
...
} elsif ( $response->type() eq 'scan' ) {
...
} elsif ( $response->type() eq 'searchRetrieve' ) {
...
}

## print out the response
print $cgi->header( -type => 'text/xml' );
print $response->asXML();

DESCRIPTION
The SRU package provides a framework for working with the Search and
Retrieval by URL (SRU) protocol developed by the Library of Congress.
SRU defines a web service for searching databases containing metadata
and objects. SRU often goes under the name SRW which is a SOAP version
of the protocol. You can think of SRU as a RESTful version of SRW, since
all the requests are simple URLs instead of XML documents being sent via
some sort of transport layer.

You might be interested in SRU if you want to provide a generic API for
searching a data repository and a mechanism for returning metadata
records. SRU defines three verbs: explain, scan and searchRetrieve which
define the requests and responses in a SRU interaction.

This set of modules attempts to provide a framework for building an SRU
service. The distribution is made up of two sets of Perl modules:
modules in the SRU::Request::* namespace which represent the three types
of requests; and modules in the SRU::Response::* namespace which
represent the various responses.

Typical usage is that a request object is created using a factory method
in the SRU::Request module. The factory is given either a URI or a CGI
object for the HTTP request. SRU::Request will look at the URI and build
the appropriate request object: SRU::Request::Explain,
SRU::Request::Scan or SRU::Request::SearchRetrieve.

Once you've got a request object you can build a response object by
using the factory method newFromRequest() in SRU::Request. This method
will examine the request and build the corresponding result object which
you can then populate with result data appropriately. When you are
finished populating the response object with results you can call
asXML() on it to get the full XML for your response.

To understand the meaning of the various requests and their responses
you'll want to read the docs at the Library of Congress. A good place to
start is this simple introductory page:
http://www.loc.gov/standards/sru/simple.html For more information about
working with the various request and response objects in this
distribution see the POD in the individual packages:

* SRU::Request

* SRU::Request::Explain

* SRU::Request::Scan

* SRU::Request::SearchRetrieve

* SRU::Response

* SRU::Response::Explain

* SRU::Response::Scan

* SRU::Response::SearchRetrieve

* SRU::Server

Questions and comments are more than welcome. This software was
developed as part of a National Science Foundation grant for building
distributed library systems in the Ockham Project. More about Ockham can
be found at http://www.ockham.org.

TODO
* create a client (SRU::Client)

* allow searchRetrieve responses to be retrieved as RSS

* make sure SRU::Server can function like real-world SRU interfaces

* handle CQL parsing errors

* better argument checking in response constructors

AUTHORS
Ed Summers <[email protected]>

COPYRIGHT AND LICENSE
Copyright 2004-2013 by Ed Summers

This library is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.