Implementation Guidelines for the Open Archives Initiative Protocol for Metadata Harvesting
	XML Schema for Gateway Descriptions
	Protocol Version 2.0 of 2002-06-14 Document Version 2004/04/23T15:17:00Z http://www.openarchives.org/OAI/2.0/guidelines-gateway.htm

Editors

The OAI Executive:
Herbert Van de Sompel <herbertv@lanl.gov> -- Los Alamos National Laboratory - Research Library
Carl Lagoze <lagoze@cs.cornell.edu> -- Cornell University - Computing and Information Science

From the OAI Technical Committee:
Michael Nelson <mln@cs.odu.edu> -- Old Dominion University - Dept of Computer Science
Simeon Warner <simeon@cs.cornell.edu> -- Cornell University - Computing and Information Science

This document is one part of the Implementation Guidelines that accompany the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH).

1. Introduction

A gateway  is a service that allows OAI-PMH access to data that are ordinarily accessible only through other protocols (e.g., Z39.50, Dienst). A notable example of a gateway is a Static Repository Gateway that provides OAI-PMH access to Static Repositories. The gateway container is used to provide information about a gateway. A gateway may include a gateway container as part of the description block in the OAI-PMH Identify response. A gateway must not embed more than one gateway container in an Identify response.

2. The gateway container

The gateway container consists of XML elements that describe the gateway itself. The gateway container must include one instance of each of the following elements:

• source - The URL of the remote source data that the gateway is making harvestable via the OAI-PMH.
• gatewayDescription - The URL of a specification that describes the gateway.

The gateway container must include one or more instance of the following element:

• gatewayAdmin - The email address of a person responsible for maintaining the gateway.

The gateway container may include one instance of each of the following elements:

• gatewayURL - The URL of the gateway itself. This element should be included when the gateway uses a URL "prefix" shared by all OAI-PMH repositories accessible through the gateway. If two repositories share the same gatewayURL, they can be assumed to be using the same gateway. A Static Repository Gateway should include the Static Repository Gateway URL as the gatewayURL.
  The gatewayURL element should not be used if the gateway does not use a shared URL "prefix". This situation could arise if, for example, a gateway used a different virtual server for each different source.
• gatewayNotes - A URL for additional notes about the particular instantiation of the gateway. This element could be used to described usage policies, software versions, and related information.

<?xml version="1.0" encoding="UTF-8"?>
<schema targetNamespace="http://www.openarchives.org/OAI/2.0/gateway/"
  xmlns="http://www.w3.org/2001/XMLSchema" 
  xmlns:oai="http://www.openarchives.org/OAI/2.0/"
  xmlns:gateway="http://www.openarchives.org/OAI/2.0/gateway/" 
  elementFormDefault="qualified" attributeFormDefault="unqualified">

  <import namespace="http://www.openarchives.org/OAI/2.0/" 
          schemaLocation="http://www.openarchives.org/OAI/2.0/OAI-PMH.xsd"/>

  <annotation>
    <documentation>
      Schema for gateways between OAI-PMH and other protocols / formats
      $Date: 2003/10/10 17:09:06 $ 
    </documentation>
  </annotation>

  <element name="gateway">
    <complexType>
      <sequence>
        <element name="source" type="string"/>
        <element name="gatewayDescription" type="anyURI"/>
        <element name="gatewayAdmin" maxOccurs="unbounded" 
                 type="oai:emailType"/>
        <element name="gatewayURL" minOccurs="0" type="anyURI"/>
        <element name="gatewayNotes" minOccurs="0" type="anyURI"/>
      </sequence>
    </complexType>
  </element>

</schema>

3. Examples

The following example shows a gateway container returned in a description block in the response to an Identify request issued against a gateway that converts between the Dienst protocol and the OAI-PMH.

<?xml version="1.0" encoding="UTF-8"?>
<gateway xmlns="http://www.openarchives.org/OAI/2.0/gateway/"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/gateway/
                      http://www.openarchives.org/OAI/2.0/gateway.xsd">
  <source>http://foo.edu/Dienst/</source>
  <gatewayDescription>http://cs-tr.cs.cornell.edu/Dienst/UI/2.0/Describe/ncstrl.cornell/TR94-1418</gatewayDescription>
  <gatewayAdmin>admin@bar.edu</gatewayAdmin>
  <gatewayAdmin>admin-alternative@bar.edu</gatewayAdmin>
  <gatewayURL>http://bar.edu/oai-gateway/2.0/</gatewayURL>
  <gatewayNotes>http://bar.edu/oai-gateway/notes.html</gatewayNotes>
</gateway>

The following example shows a gateway container returned in a description block in the response to an Identify request issued against a gateway that converts between the Static Repository Format and the OAI-PMH.

<?xml version="1.0" encoding="UTF-8"?>
<gateway xmlns="http://www.openarchives.org/OAI/2.0/gateway/"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/gateway/
                      http://www.openarchives.org/OAI/2.0/gateway.xsd">
  <source>http://an.oai.org/ma/mini.xml</source>
  <gatewayDescription>http://www.openarchives.org/OAI/2.0/guidelines-static-repository.htm</gatewayDescription>
  <gatewayAdmin>pat@institution.org</gatewayAdmin>
  <gatewayURL>http://bar.edu/oai-gateway/2.0/</gatewayURL>
  <gatewayNotes>http://gateway.institution.org/oai/</gatewayNotes>
</gateway>

Acknowledgements

Support for the development of the OAI-PMH and for other Open Archives Initiative activities comes from the National Science Foundation through Grant No. IIS-9817416. Individuals who have played a significant role in the development of OAI-PMH version 2.0 are acknowledged in the protocol document.

Document History

2004-04-23: Released with Specification for an OAI Static Repository and an OAI Static Repository Gateway.
2003-10-10: Beta release.
2002-11-13: Alpha release.
2002-11-08: First version of this document.