1. Using XML, XSLT, and CSS in a Digital Library
Markup Transformations
SGML to XML Conversions
Metadata Schema & Generation
Robert Ferrer
ASIS Annual Meeting 2000

2. SGML to XML Conversions - Modular
15 November 2000
ASIS Annual Meeting 2000

3. SGML to XML Conversions - Basic
Empty tags <empty> to < ….. />
<?Processing Instruction> to <? ……... ?>
CDATA to CDATA sections <![CDATA[ … ]]>
Named entities remain unchanged - α
<!DOCTYPE ...> refers to XML DTD containing only character entity definitions to Unicode points <!ENTITY alpha “&#945”>
15 November 2000
ASIS Annual Meeting 2000

4. SGML to XML Conversions - Linking
Attributes to facilitate internal linking
<CITEREF REFID="bib5" idli_occurrence=”3” />
External links represented as XLinks
<FIG NAME=“F1” xlink:type=“simple” xlink:href=“fig1.jpg” xlink:show=“new” xlink:actuate=“user” />
15 November 2000
ASIS Annual Meeting 2000

5. SGML to XML Conversions - Math
SGML Math converted to MathML
Presentational MathML
<math xmlns=“
<msubsup>
<mrow><mi>α</mi></mrow>
<mrow><mi>i</mi></mrow>
<mrow><mo>-</mo><mn>2</mn></mrow>
</msubsup>
</math>
ISO Math
<dformula>
<g>a</g>
^-2
<inf>i</inf>
</dformula>
Identify & translate mathematical character references
Identify & tokenize mathematical content
15 November 2000
ASIS Annual Meeting 2000

6. SGML to XML Conversions - Math
Recognize & transform mathematical markup
<xsl:template match=“dformula”> : <xsl:when test="sup or inf">
<xsl:for-each select="child::node()">
<xsl:choose>
<xsl:when test="name(self::node())='sup' and name(following sibling::node()[1])='inf'">
<xsl:element name="msubsup” namespace=“
<xsl:element name="mrow” namespace=“
<xsl:apply-templates select="preceding-sibling::node()[1]"/>
</xsl:element>
15 November 2000
ASIS Annual Meeting 2000

7. SGML to XML Conversions - TeX
TeX converted to GIF images
<FORM NOTATION="TEX" HIDE="TRUE"> $$ (j_0-a_2')\,{\rm mod}\,P $$</FORM><uie name= “uie1” xlink:type="simple" xlink:href="fig1.gif" xlink:show="new" xlink:actuate="user” />
TeX converted into MathML
IBM TechExplorer $$
(j_0-a_2')\,{\rm mod}\,P
<math><mo>(</mo><msub>
<mrow><mi>j</mi></mrow> <mrow><mn>0</mn></mrow> </msub><mi>−</mi>
<msubsup><mrow><mi>a</mi>
</mrow><mrow><mn>2</mn>…..
15 November 2000
ASIS Annual Meeting 2000

8. SGML to XML Conversions - DTD
XML DTD does not permit inclusions and exclusions
SGML:<!ELEMENT Article - - (front, body) +(%i.float;)>
XML:<!ELEMENT Article (front | body | %i.float;)*>
XML DTD does not permit the ‘&’ connector
XML DTD does not permit the use of mixed content models
<!ELEMENT Other ((author, journal) | (#PCDATA))>
15 November 2000
ASIS Annual Meeting 2000

9. Metadata - Usage Metadata Within the DLI Testbed
Normalize key fields from different publisher DTDs to facilitate searching
Provide common and easily displayable intermediate search results
Add value in the form of links to cited or citing articles within the Testbed, external abstracts and indexes, etc.
15 November 2000
ASIS Annual Meeting 2000

10. Metadata - Schema
Resource Description Framework (RDF) provides standardized way to represent metadata using XML
Encapsulates metadata elements
Provides varying levels of granularity
RDF container objects describe the relations between repeated metadata elements
15 November 2000
ASIS Annual Meeting 2000

11. Metadata - Schema
Dublin Core (DC) model is used to encapsulate all searchable metadata
Provides the semantic framework for describing each object in the collection Content Intellectual Property Instantiation Title Creator Date Subject Publisher Format Description Contributor Identifier Type Rights Language Source Relation Coverage
15 November 2000
ASIS Annual Meeting 2000

12. Metadata - Schema Extensive custom IDLI tags are included
Offer a further level of granularity
<DC:Description><idli:Abstract></DC:Description>
Search clients familiar with IDLI schema can achieve much greater precision
Dublin Core Qualifiers (DCQ) substructure to replace many of the project-specific IDLI elements
<DC:Description><DCQ:Abstract></DC:Description>
15 November 2000
ASIS Annual Meeting 2000

13. Metadata - Schema <rdf:seq> <rdf:li> <dc:Creator>
<idli:author_name>Giust, G. K.</idli:author_name>
<idli:organization_name>Department of Electrical Engineering, Arizona State University</idli:organization_name>
</dc:Creator>
</rdf:li>
<idli:author_name>Sigmon, T.W.</idli:author_name>
<idli:organization_name>Department of Computer Science, Illinois State University </idli:organization_name>
</rdf:seq>
15 November 2000
ASIS Annual Meeting 2000

14. Metadata - Extracting Metadata is extracted from the ‘base’ XML files
Utilization of XML Header
DTD is used to resolve entities
XML-Stylesheet processing instruction
Visual Basic application serves as parser
Document Object Model (DOM)
XSLT Style Sheets
15 November 2000
ASIS Annual Meeting 2000

15. Metadata - Extracting Utilization of XSLT Style Sheets
XSLT transformative features to generate base metadata file and forward citation fragment
XSLT scripting features to generate elements not directly expressed in the document
XSLT instantiation of ActiveX objects to test for links
15 November 2000
ASIS Annual Meeting 2000

16. Metadata - Extracting Utilization of DOM
Insert pseudo elements (e.g. bibliographic data)
Search reference citations from the generated metadata object to insert forward references into other metadata files
15 November 2000
ASIS Annual Meeting 2000