Effective XML

• Please turn off all
• Speaker’s Qualifications
• Part I: XML Overview
• What is XML?
• XML is a Meta Markup Language
• Rule 1: Focus on Meaning, Not Appearance
• A Song Description in HTML
• A Song Description in XML
• Elements
• Rule 2: Subdivide Elements Into the Smallest Units of Information
• Cascading Style Sheets
• CSS Stylesheet for Songs
• Attaching style sheets to documents
• song.xsl
• Applying an XSLT Style Sheet
• Output
• CSS or XSL?
• Editing and Saving XML Documents
• Rule 3: Prefer UTF-8
• Questions?
• Well-formedness
• Well-formedness Rules
• Open and close all tags
• Empty-element tags end with />
• There is a unique root element
• Elements may not overlap
• Attribute values are quoted
• < and & are only used to start tags and entities
• Only the five predefined entity references are used
• Numeric Character References
• Rule 4: Never compromise on well-formedness
• Questions?
• Validity
• A DTD for Songs
• A Valid Song Document
• Checking Validity
• Well-formedness vs. validity
• DTDs and Validity
• What is a DTD?
• Internal DTD Subsets
• The importance of validation
• Comments in DTDs
• Rule 5: Do compromise on validity
• A More Complex Example
• The XML Declaration
• Rule 6: Include an XML Declaration
• Empty-element Tags
• Rule 7: Don't assign meaning to Empty-element Tags
• Attributes
• Rule 8: Use Attributes for Metadata; Elements for Content
• Rule 8.5: When not to use attributes
• Comments
• Rule 9: Don't Rely on Comments
• Processing Instructions
• Rule 10: Use processing instructions for prcess specific content
• Mixed Content
• Rule 11: Provide for Mixed Content
• A More Complex DTD
• Questions?
• Namespaces
• Raison d'etre
• The Need for Namespaces
• Namespaces disambiguate elements
• Namespace Syntax
• Namespace URIs
• Binding Prefixes to Namespace URIs
• Binding Prefixes to Namespace URIs Example
• The Default Namespace
• Unprefixed attributes are never in any namespace
• Rule 13: URIs matter; not prefixes
• Namespace URIs do not necessarily point to a document, page, or schema
• Namespaces and DTDs
• Questions?
• Rule 12: Prefer Numeric Character References
• What is XML used for?
• Domain-Specific Markup Languages
• Self-Describing Data
• An XML Fragment
• Interchange of Data Among Applications
• Can assemble data from multiple sources
• XML Applications
• Example XML Applications
• Mathematical Markup Language
• RSS
• Books
• Vector Graphics
• SOAP
• WSDL
• Database interchange and export
• Narrative vs. Record-Like
• XML is not:
• XML for XML
• XSL: The Extensible Stylesheet Language
• Schemas
• W3C XML Schema Language Example
• XLinks
• File Formats, in-house applications, and other behind the scenes uses
• When should you not use XML?
• Questions?
• Processing XML
• SAX
• Processing XML with Java is easy
• XML API Styles
• Parser APIs
• XML Infoset
• Markup and Character Data
• Markup and Character Data Example
• Entities
• Parsed Character Data
• CDATA sections
• How Parsers Handle Namespaces
• The Five Layers of XML Processing
• Questions?
• Writing XML Documents with Java
• You don't always need a new API
• Unicode
• Readers and Writers
• A Java program that writes Fibonacci numbers into a text file
• fibonacci.txt
• A Java program that writes Fibonacci numbers into an XML file
• fibonacci.xml
• Single quoted attribute values are a little cleaner
• Suppose you want to include a DTD
• valid_fibonacci.xml
• Questions?
• To Learn More
• Reading XML Documents with SAX
• Reading XML Documents
• SAX
• SAX Parsers for Java
• The Horrors of the CLASSPATH
• The SAX2 Process
• Making an XMLReader
• Parsing a Document with XMLReader
• Sample Output from SAX2Checker
• JAXP Brain Damage
• The ContentHandler interface
• A Sample Application
• Goal: Return a list of all the URLs in this list as java.net.URL objects
• SAX Design
• User Interface Class
• ContentHandler Class
• Weblogs Output
• Event Based API Caveats
• To Learn More
• Questions?
• DOM, The Document Object Model
• Trees
• Document Object Model
• DOM Evolution
• DOM Implementations for Java
• Eight Modules:
• DOM Trees
• org.w3c.dom
• The DOM Process
• Parsing documents with a DOM Parser Example
• The JAXP Process
• Parsing documents with a JAXP DocumentBuilder
• The Node Interface
• The NodeList Interface
• Node Reporter
• Node Reporter Output
• Node Values as returned by getNodeValue()
• The Document Node
• The Document Interface
• A Sample Application
• DOM Design
• Weblogs with DOM
• Weblogs Output
• Element Nodes
• The Element Interface
• IDTagger
• Output from IDTagger
• Namespaces in DOM
• Writing XML Documents with DOM
• The DOMImplementation interface
• org.apache.xerces.dom.DOMImplementationImpl
• A Xerces/DOM program that writes Fibonacci numbers into an XML document
• A JAXP/DOM program that writes Fibonacci numbers into an XML document
• Serialization
• A DOM program that writes Fibonacci numbers onto System.out
• fibonacci.xml
• OutputFormat
• Better formatted output
• formatted_fibonacci.xml
• DOM based XMLPrettyPrinter
• Output from a DOM based XMLPrettyPrinter
• The point is this:
• Questions?
• To Learn More
• To Learn More
• Questions?

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