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Developing a Generic Toolkit: Architecture and technology issues ALLC/ACH Conference 2003 Chris Turner. Generic Criteria. Achieving Reusability through: System independence Standardisation Availability & cost Support Sustainability. TVS Model.
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Developing a Generic Toolkit: Architecture and technology issues ALLC/ACH Conference 2003 Chris Turner LEADERS: Linking EAD to Electronically Retrievable Sources
Generic Criteria • Achieving Reusability through: • System independence • Standardisation • Availability & cost • Support • Sustainability LEADERS: Linking EAD to Electronically Retrievable Sources
TVS Model • The TVS model (Carvalho & Cordeiro, 2002) • proposes a structured framework for the exploitation of XML technologies • Transport • Data exchange, transfer between systems • Validation • Structure, semantics, basic data typing • Services • Reuse of search and display functionality LEADERS: Linking EAD to Electronically Retrievable Sources
Web Services • Web Services is an umbrella term for a set of standards which are about communication between separate software programs. They address the process of exchanging data and instructions between different programs. The programs may be resident on different computers, with different operating systems and written in different languages. Web Services use XML as the file format and HTTP as the transport protocol. LEADERS: Linking EAD to Electronically Retrievable Sources
System Components User PC/Mac/X Web Browser Server – Linux/Unix/Windows LEADERS application LEADERS Toolkit • Digitised/Encoded Resources LEADERS: Linking EAD to Electronically Retrievable Sources
Digitised/Encoded Resources EAC XML files – Descriptive metadata about People, Organisations and families • EAD XML file – • Contains metadata including index terms regarding the entire collection and resources – • Original documents • Transcripts • Images TEI XML files – Transcripts of original documents Image JPEG files – Digitised images of original documents LEADERS: Linking EAD to Electronically Retrievable Sources
System Components User PC/Mac Web Browser Server – Linux/Unix/Windows LEADERS application LEADERS Toolkit • Digitised/Encoded Resources LEADERS: Linking EAD to Electronically Retrievable Sources
Toolkit LEADERS Application SOAP XML Messages generated to carry messages between application and toolkit WSDL- XML file describing services – utilized by application • Services, written in Java: • Search name/place/topic indexes – return browse list containing nearest match plus four entries above and below in index. • Search by name, place, topic, date individually or in combination – return hitlist • Search by id – return detailed object display Search Engine XML Index document derived from EAD finding aid by stylesheet Digitised/Encoded Resources: LEADERS: Linking EAD to Electronically Retrievable Sources
Toolkit • Components: • Server environment: Apache Cocoon • Parser, Processors, etc.: • JAXP (Sun), dom4j, Xerces, Xalan, FOP. • Search engine: Lucene • System neutral; Open source; Supported by Apache Software Foundation LEADERS: Linking EAD to Electronically Retrievable Sources
Toolkit • Reusability: • Can be applied to other resources encoded according to the schema rules. • Services can be consumed by multiple applications. • Services may be added or extended. • Can be hosted on Windows/Unix/Linux. LEADERS: Linking EAD to Electronically Retrievable Sources
System Components User PC/Mac Web Browser Server – Linux/Unix/Windows LEADERS application LEADERS Toolkit • Digitised/Encoded Resources LEADERS: Linking EAD to Electronically Retrievable Sources
Application • Hosted by Apache Tomcat • ‘Consumes’ Web Services • Components • Java server pages • Stylesheets • Cascading Stylesheets LEADERS: Linking EAD to Electronically Retrievable Sources
Application • Reusability • Same application can be used to access different resources served up by the Web Services. • New applications can be created to consume services accessing the same or different resources e.g.: • Integration with an educational application • Study of palaeography • Focus on biographical or authority information • On-line ordering of images/offprints/document production LEADERS: Linking EAD to Electronically Retrievable Sources
Summary • Reusability at all levels: • Resource files may be re-used as stand alone files and/or as components in one or more LEADERS applications. • Toolkit can support multiple resource sets and multiple applications in multiple environments. • Applications can access multiple resource sets in multiple environments. LEADERS: Linking EAD to Electronically Retrievable Sources
LEADERS Demo application • An instance of a LEADERS Application. • Concentration on the detailed presentation of resources, rather than on search interface. • Built for the purpose of gaining user feedback. • Example screen shots of demonstrator application. LEADERS: Linking EAD to Electronically Retrievable Sources