XSLT Transformation Overview

Date: 10 December 2004
Creator: Michael Ferrando, Library of Congress (202-707-4454)
Stylesheet name: EAD_2002_HTML_conv-1.xsl
Language: XSLT 1.0
Design Pattern: Rule based
Terms of use: Provided without warranty or formal technical support service.
Support: List serve EAD@loc.gov
Source document: EAD 2002 XML
Objective: Create an opened ended stylesheet that could incorporate user preferences and web environments. Establish a rule based design written in strict accord with the DTD and with Library of Congress current practices document. Develop a methodology in order to control and process elements that would insure longevity and compatibility with other mark up languages. Design a modular structure which enables the building and restructuring of future user formatting preferences as well as allowing for recursive elements. Retain readability and navigation of the stylesheet through a determined template order (hierarchical; element type; alphabetical by element or attribute). Provide comments to give context and logical flow of expressions and conditions for processing the data. Implement a workflow that would create a standard of display, formatting, and user interaction for future XML development at the Library of Congress.

Stylesheet architecture:

• Global variables
• Root template
• EADHEADER template
• ARCHDESC template
  • *
  • DSC template
    • Components templates
  • *
• ARCHDESC children templates
• Mechanical templates (linking)
• Text elements templates (ComplexType mixed="true")
• Formatting objects templates (LIST; TABLE; etc.)
• Special templates
• Wildcard templates

Result Tree Associations:

• EADHEADER = Titlepage
• ARCHDESC/* = Prologue
• ARCHDESC/DSC = Body
• ARCHDESC/* = Epilogue

External XML Source Documents:

• EAD_SPECIAL_FA-1.xml
  • User created formatting switches for DSC template
  • Currently 2 types of formatting (unitid | tabular)
• EAD_LINKS-1.xml
  • CSS values for Web environment (colors, etc.)

EAD User/Coder Forum:

• Template Rules Overview (dsc//did/*)
  • A brief description of the criteria used to determine inline transformations of siblings. Diagrams (SVG) and code examples are included.

Further developments: The successful design of this stylesheet has been demonstrated with the creation of PDF documents from EAD. The same stylesheet design is used with XSL-FO mark up. The same external XML source documents are used when the PDF is generated from EAD. The tabular formatting preference creates landscape flows in the body of the finding aid for special tabular displays (See: Exit Art "Reactions" Exhibit Collection). More importantly, the both stylesheets can be updated (when relevant) to insure uniformity of the new standard for EAD formatting and display.

Updated: 11 January 2005