1. Information Design Trends Unit 4: Sources and Standards Lecture 3: A Brief Introduction to XML

2. Publishing Requirements for Industry Standard Metadata (PRISM) PRISM is a set of metadata vocabularies that assist in the automation of publishing production processes and content exchange. Allows asset-metadata to speak the same language and are understood by all. Defined in XML.

3. Markup Languages Markup is a term for metadata. Information about Information A markup language refers to agreement within a community on the meaning and use of a set of tags: HTML is the most common  “This word is bold ”  “ This is a level one heading ” Not just used for the Web

4. The Problem with HTML The title page of the book Captain Corelli's Mandolin: Captain Corelli’s Mandolin Louis de Bernières © 1994 by Louis de Bernières To my mother and father Dr Iannis Commences His History and is Frustrated Dr Iannis had enjoyed a satisfactory day... HTML only conveys structure and format information. HTML cannot convey any sense of the content of the document. HTML can support only limited processing of a document and its contents.

5. The Exstensible Markup Language (XML) XML is not a markup language but a language for creating markup languages. XML also refers to the entire family of XML- related standards. XML is used to represent data and to write applications to process that data. The primary uses of XML are: Exchanging information Enabling styling and presentation. Defining a storage format.

6. A Basic XML Document Tony Stewart Senior Consultant Head Office 433 Hackensack Avenue

7. Defining XML Documents Document Types and Instances: A document type defines the rules used to markup a set of documents A document instance is a particular document from a given set of documents Schemas and DTDs: Document Type Definitions are the original mechanism created to define a document grammar Schemas provide additional information enabling much more sophisticated modeling and processing

8. Well-formed and Valid Well-formed XML conforms to a set of built-in structural rules, including: One unique "root" element Every non-empty element has matching start and end tags All elements nested, with no overlaps Various character and name restrictions Valid XML is well-formed and: References or includes a schema or DTD Conforms to the rules in that schema

9. Benefits of XML Loose Coupling. Communicating between systems using predefined message formats, without knowing the details of each other's systems Self-Describing Data. An XML document always contains its element/column/object names, and optionally includes or references its entire schema.

10. Presentation & Transformation Extensible Style Language (XSL): XSLT - A transformation is the process of using XSLT to convert an XML document to another format, either XML or non-XML Xpath - Pointing allows us to unambiguously identify any location or type of location in an XML document XSL Formatting - Applying formatting to information without having to write instructions that are specific to a particular output device