web services for digital library construction
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Web Services for Digital Library Construction. T. Hickey Indo-US Workshop June 2003. What are Web Services?. Machine-to-machine communication Run over standard Web protocols XML syntax, HTTP packaging Several approaches REST Representational State Transfer SOAP - PowerPoint PPT PresentationTRANSCRIPT
Web Services forDigital Library Construction
T. Hickey
Indo-US Workshop
June 2003
What are Web Services?
• Machine-to-machine communication• Run over standard Web protocols
– XML syntax, HTTP packaging
• Several approaches– REST
• Representational State Transfer
– SOAP• Simple Object Access Protocol
REST
• REST is simplest– Send an HTTP request– Get back a response (XML, HTML)– Examples
• Web browser• OpenURL• Z39.50 as a Web service: SRU
http://sfx.bath.ac.uk/sfxmenu?genre=book&isbn=1234-5678
http://www.kb.nl/cgi-zoek/srw.pl?query=test&maxRec=10&recSchema=dc_record
SOAP is more complex
• Simple Object Access Protocol
• Z39.50 as a SOAP service: SRW– http://www.loc.gov/z3950/agency/zing/srwu/wsdl/zing_srw_binding.wsdl
• WSDL
• UDDI
A set of Web services for the digital library
• Register• Search• Resolve• Navigate• Decompose• Enhance• Transform
Skip to examples
Registration Services
• Metadata about metadata– Dublin Core extensions– Digital format descriptions
• Metadata about objects– Books– Web resources
• Metadata about agents– People– Institutions
Search Services
• Go from data to links– Name to preferred form– Search terms to record list
Resolution Services
• From links to data– Record numbers to records– Controlled names to name metadata– Class number to textual description
Navigation Services
• Movement within hierarchies– Classification, e.g. DDC– FRBR (work, expression, manifestation, item)
• General network movement– Link selection and following
Decomposition Services
• DDC Numbers
• Names within a list
• Citations within a paper
• Structure of a document
• Letters within an image
Enhancement Services
• Normalization– Linkage to registered forms
• Addition of DDC numbers
• Authority control on agents
• Content augmentation– Add information to a brief record from a
matching longer record
Transformation Services
• Syntax translation– MARC21 to MARC XML
• Semantic translation– Qualified Dublin Core to MARC21– Library of Congress SH to FAST
• Content translation– English to French?
Examples of Web Services
• XISBN service– Maps ISBNs to ISBNs
• OpenURL Registry– Provides names and definitions for OpenURL
services
• GSAFD Thesaurus
The XISBN Web Service
User
Amazon
Library
FRBRizedISBN Server
On Amazon
Cornell University
OpenURL Registry
• OAI-PMH Registry– http://purl.org/openurl/ – OAI implies XML delivered
• But, stylesheets can produce– HTML display– Web browser user interface
GSAFD as a test case
• Enhanced subject authority records for genre terms are now available via the OAICat framework. This development is a result of the combined efforts of the OAICat project and the Terminology Services project. The enhanced authority file is a version of the MARC 21 authority records for GSAFD genre terms. The enhanced version of the file has the following features:
– The content of the file is MARC XML
– Established terms in the file are accessible via a URL
– Established terms in the file are mapped to equivalent Library of Congress Subject Headings (lcsh) and Library of Congress subject headings: Annotated Card Program (lcshac) (i.e., LC Children’s heading)
– Authority records can be displayed in MARC or in a thesaurus-style display
– The file is also accessible via SRW/SRU under the Zthes protocol