Z39.50 & XML Poul Henrik Jørgensen, Danish Bibliographic Centre

Z39.50 & XMLPoul Henrik Jørgensen, DBC2 Background Moderate number of Z39.50 Servers Little take-up outside major research libraries Many limited to basic search and retrieval Mostly used for Web-to-Z gateways Requirements for related services, e.g. Item Order or Circulation Time-consuming to implement Z39.50

Z39.50 & XMLPoul Henrik Jørgensen, DBC3 Issues Technology is alien to mainstream IT infrastructure Limited development tools Few developers Proprietary C-libraries Inaccessible specifications. Plethora of esoteric features No common (object-based) API BER data format is not eye-readable

Z39.50 & XMLPoul Henrik Jørgensen, DBC4 Objectives Leverage investments in existing Z39.50 Services and specifications Simplify Z39.50 implementation Facilitate interoperability with other relevant standards Foster migration of Z39.50 functionality to mainstream IT technologies

Z39.50 & XMLPoul Henrik Jørgensen, DBC5 First Steps Introduce XML as Z39.50 Transfer Syntax Specify new Z39.50 data structures as XML Schemas Encode complex hierarchical data within XML documents Use XML as alternative to GRS-1

Z39.50 & XMLPoul Henrik Jørgensen, DBC6 XML structures in Z39.50 Holdings XML Schema gsSchema6a.xsd gsSchema6a.xsd ExplainLite Server information Dublin Core/RDF Extended Services Task Packages

Z39.50 & XMLPoul Henrik Jørgensen, DBC7 SOAP Overview SOAP is a protocol to transport XML data Initially designed for Remote Procedure Calls Utilise normal HTTP POST to send a Request and receive Response from a Web (SOAP) Server Parameters are carried as XML structures within normal HTTP body Primary input to W3C XML Protocol work

Z39.50 & XMLPoul Henrik Jørgensen, DBC8 ZML: Z39.50 over SOAP Existing ASN.a protocol elements encoded as XER Structures Relevant Z39.50 Services mapped to SOAP Request/Response functions over HTTP Protocol parameters encoded as XML SOAP parameters via XER Existing Web-to-Z gateways may be enhanced with SOAP-to-Z gateways

Z39.50 & XMLPoul Henrik Jørgensen, DBC9 <SOAP:Envelope xmlns:SOAP=" xmlns:xsi=" xmlns:xsd=" SOAP:encodingStyle=" version-1 version-2 search present scan <ez:preferredMessageSize xsi:type="xsd:int"> OCLC z39.50 API <ez:implementationVersion xsi:type="xsd:string">3.0 Init Request Example

Z39.50 & XMLPoul Henrik Jørgensen, DBC10 Interface Specs. in WSDL WSDL is a formal top-down method to specify interfaces to Web (SOAP) Services General interfaces to eZ3950, NCIP and related protocols can be specified with XML Schemas and WSDL

Z39.50 & XMLPoul Henrik Jørgensen, DBC11 NCIP WSDL Example

Z39.50 & XMLPoul Henrik Jørgensen, DBC12 ZML Development ZML Profile of Z39.50 over SOAP Optional Init & Close Search & Scan based on Bath Profile ISO2709/XML Present format by Ray Denenberg & P.H. Jørgensen ZML Server & Client prototypes Common Z39.50 Testbed

Z39.50 & XMLPoul Henrik Jørgensen, DBC13 Conclusions XML is already implemented within several Z39.50 functions XML is easier and more flexible than ASN.1/BER in practice Most of Z39.50 can be migr á ted to XML/SOAP (eZ3950) Interoperability with related SOAP based protocols can be facilitated via comon WSDL interface specifications