Jennifer Widom

XML DataIntroduction, Well-formed XML

Jennifer Widom

Well-Formed XMLExtensible Markup Language (XML) Standard for data representation and exchange Document format similar to HTML• Tags describe content instead of formatting

Also streaming format

Jennifer Widom

Well-Formed XML

Basic constructs Tagged elements (nested) Attributes Text

Jennifer Widom

Well-Formed XMLRelational Model versus XML

Relational XML

Structure

Schema

Queries

Ordering

Implementation

Jennifer Widom

Well-Formed XML“Well-Formed” XMLAdheres to basic structural requirements• Single root element• Matched tags, proper nesting• Unique attributes within elements

Jennifer Widom

Well-Formed XML“Well-Formed” XMLAdheres to basic structural requirements• Single root element• Matched tags, proper nesting• Unique attributes within elements

XMLParser

XMLDocument Parsed XML

“Not well-formed”

Jennifer Widom

Well-Formed XMLDisplaying XMLUse rule-based language to translate to HTML• Cascading stylesheets (CSS)• Extensible stylesheet language (XSL)

Jennifer Widom

Well-Formed XMLDisplaying XMLUse rule-based language to translate to HTML• Cascading stylesheets (CSS)• Extensible stylesheet language (XSL)

CSS/XSLinterpreter

XMLDocument

(data)

Rules

HTMLDocument(look at)

Jennifer Widom

Well-Formed XMLExtensible Markup Language (XML) Standard for data representation and exchange Formal specification is enormous; we cover most important components