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Aimed solution for implementing the TEL Portal (draft - The

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Aimed solution for implementing the TEL Portal (draft - The ...

IST 2000 25347/Aimed solution for the TEL test portal

     The European Library TEL

     IST 2000 25347

     Aimed Solution for

     Implementing the TEL Portal

Name of Client:

Distribution List:

    Author: Theo van Veen, Annette Siegenthaler, Bill Oldroyd

Authorized by:

Contractual Date:

     0.4 (draft version) Date: 13.8.2003 Issue:

     WP4 Interoperability Testbeds Workpackage:

Deliverable Number / Type / Nature

Reference:

Total Number of Pages:

Contact Details for Organisation:

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    IST 2000 25347/ Aimed solution for the TEL test portal

    Table of Contents:

1 Document Control 1

    1.1 Abstract 1

    1.2 Keywords 1

    2 Management Overview 2

    2.1 Executive Summary 2

    2.2 Scope Statement 2

    3 Introduction 3

    3.1 Glossary 3

    4 Development of the TEL portal architecture. 4

    4.1 The conventional portal architecture. 4 4.2 The SRU test interface architecture. 4 4.3 The introduction of the SRU Z39.50 gateway. 5 4.4 The introduction of xslt middleware. 6 5 Concepts incorporated into the SRU test portal 7

    5.1 Content and layout/functionality are separated 7 5.2 Requests are SRU compliant 7

    5.3 Multiple requests are launched and processed in the browser 7

    6 Benefits, drawbacks and required developments 9

    6.1 Benefits 9

    6.2 Drawbacks 9

    6.3 Required developments 9

    7 description of the current TEL test portal 11

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    IST 2000 25347/Aimed solution for the TEL test portal 1 DOCUMENT CONTROL

    Issue Date of issue Comments

    0.1 04 August 2003 First Draft, request for comments until

    0.2 12 August 2003 Second draft with comments from BO and TVV

    0.3 13 August 2003 Third draft with some minor corrections

    0.4 14 August 2003 Forth draft with comments of JK

1.1 Abstract

    This document describes the solution of the current SRU test portal and outlines the amendments that should be 1applied in order to implement the operational TELService system (including a TELService interface), which 1would be developed after completion of the TELProject . The aimed concept declines from the original idea of

    a central commercial portal and it is described how this change in thinking is achieved. Additionally the advantages and drawbacks are described and developments that are needed to limit the impact of these drawbacks.

1.2 Keywords

    TEL, National Libraries, Search and Retrieval on the Web, Z39.50 protocol, ZiNG, SRU, XML representation, Distributed Bibliographic Resources, Digital Publications

     1 For clarity the following terms are used in this document:

    TELProject refers to the present project which is an EU subsidised accompanying measure

    TELService refers to the operational service for which the present project as an accompanying measure is preparing and to which the partners have committed. TELService is a shared central service that gives access to local services offered by partner libraries.

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    IST 2000 25347/ Aimed solution for the TEL test portal 2 MANAGEMENT OVERVIEW

    2.1 Executive Summary

    This document is supposed to serve as a basis for formal assessment of the desired solution for the TELService.

    It should as well serve as basis for the technical specification that has to precede the implementation of the

    TELService. It won’t become a formal Deliverable, but remains as an internal paper to the project. 2.2 Scope Statement

    This document describes the concept of a portal running as a part of the browser in relation to a conventional

    portal running as central service and some required developments are described for turning the original test

    interface on in which this concept is used, into am initial production system. It will not replace a detailed

    technical description of the complete and final TELservce.

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IST 2000 25347/Aimed solution for the TEL test portal

    3 INTRODUCTION

The TELservice was original thought to be a commercial portal giving access to distributed metadata via Z39.50

    and to a central index via http/XML. At the start of the TELproject the Z39.50 Implementers Group started the

    specification of a new standard for search and retrieve (SRU/SRW) as a part of a broader initiative called Z39.50

    internation Next Generation (see http://www.loc.gov/z3950/agency/zing/). SRU being Search and Retrive via URLs was adopted by TEL for http/XML access of the central index. For testing the implementation of this

    protocol a test interface was developed using the XSL capabilities of the Internet Explorer. This test interface

    (see http://krait.kb.nl/coop/tel/portal/TEL.html) was based on Javascript and XSL and showed to be a simple but

    powerful tool to demonstrate potential portal functionality, mainly because it was easy to integrate search and

    retrieval, navigation and presentation just by combining Javascript with XSL. This interface was also used for

    the metadata development of the TEL project.

    When it showed to be easy to build a gateway to Z39.50 systems, it was expected that this solution might be a

    low-cost and powerful alternative to a commercial portal. As such it was advised to the TEL steering committee

    as an extra option.

3.1 Glossary

    CQL Common Query Language. CQL is the query language for SRW and SRU, and may be used by

    other protocols as well. CQL is designed to be human readable and writable, while maintaining

    the expressiveness of more complex languages. SRU Search and Retrieve via http. A protocol using http/XML still under development and being

    used for the TEL http/XML testbed described in this document. URL Uniform Resource Locator. A string that identifies a resource (document or service) in the

    web. It can serve as a web address for a hypertext link. XML Extensible Mark-up Language. Agreed record syntax in TEL. XSL XSL is a family of recommendations for defining XML document transformation and

    presentation (Internet: http://www.w3.org/Style/XSL/). XSLT Part of XSL. An XSLT stylesheet specifies the presentation of a class of XML documents by

    describing how an instance of the class is transformed into an XML document.

    Z39.50 International standard (ISO 23950) that defines a protocol for computer-to-computer

    information retrieval.

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    IST 2000 25347/ Aimed solution for the TEL test portal

    4 DEVELOPMENT OF THE TEL PORTAL ARCHITECTURE.

In this section the aimed solution for the TELService is described by the development of the ideas of the TEL

    architecture from the original ideas via implemented test interfaces to a production architecture that still has to be

    developed.

4.1 The primary portal architecture.

The primary portal solution aimed for the operational TELService is shown below. It was a conventional

    approach: A central portal receives an http request from a browser and converts this request to Z39.50 requests,

    broadcasts these requests to different Z39.50 targets simultaneously, waits for the responses and converts the

    results into an HTML presentation. In case of TEL the request is also converted to a SRU request and sent to one

    or more SRU servers, including the central database of harvested metadata.