XML Schema: (O'Reilly Ser.)

For creating or using formal descriptions of XML vocabularies, this text offers a set of tools for defining acceptable document structures and content. An alternative to DTDs as the way to describe and validate data in an XML environment, the book should enable developers to create precise descriptions with a richer set of datatypes-such as booleans, numbers, currencies, dates and times - that are useful for modern applications. It explains the ins and outs of XML Schema, including design choices, best practices, and limitations. Particularly valuable are discussions of how the type structures fit with existing database and object-oriented program contexts. With XML Schema, you can define acceptable content models and annotate those models with additional type information, making them more readily bound to programs and objects. Schemas combine the easy interchange of text-based XML with the more stringent requirements of data exchange, and make it easier to validate documents based on namespaces. Examples are included that demonstrate the details necessary for precise vocabulary definitions. Topics covered within the book include: foundations of XML Schema syntax; flat, "russian-doll", and other schema approaches; working with simple and complex types in a variety of contexts; the built-in datatypes provided by XML Schema; using facets to extend datatypes, including regular expression-based patterns; using keys and uniqueness rules to limit how and where information may appear; creating extensible schemas and managing extensibility; and documenting schemas and extending XML schema capabilities. In addition to the explanatory content, XML Schema offers a complete reference to all parts of both the XML Schema structures and XML Schema datatypes specifications, as well as a glossary. Appendices explore the relationships between XML Schema and other tools for describing document structures, including DTDs, RELAX NG, and Schematron, as well as work in progress at the W3C to more tightly integrate XML Schema with existing specifications.

Table of Contents:
1. Schema Uses and Development What Schemas Do for XML W3C XML Schema 2. Our First Schema The Instance Document Our First Schema First Findings 3. Giving Some Depth to Our First Schema Working From the Structure of the Instance Document New Lessons 4. Using Predefined Simple Datatypes Lexical and Value Spaces Whitespace Processing String Da tatypes Numeric Datatypes Date and Time Datatypes List Types What About anySimpleType? Back to Our Library 5. Creating Simple Datatypes Derivation By Restrict ion Derivation By List Derivation By Union Some Oddities of Simple Types Back to Our Library 6. Using Regular Expressions to Specify Simple Datatypes The Swiss Army Knife The Simplest Possible Patterns Quantifying More Atoms Common Patterns Back to Our Library 7. Creating Complex Datatypes Simple Versus Complex Types Examining the Landscape Simple Content Models Complex Content Models Mixed Content Models Empty Content Models Back to Our Library Derivation or Groups 8. Creating Building Blocks Schema Inclusion Schema Inclusion with Redefinition Other Alternatives Simplifying the Library 9. Defining Uniqueness, Keys, and Key References xs :ID and xs:IDREF XPath-Based Identity Checks ID/IDREF Versus xs:key/xs:keyref Using xs:key a nd xs:unique As Co-occurrence Constraints 10 Controlling Namespaces Namespaces Present Two Challenges to Schema Languages Namespace Declarations To Qualify Or Not to Qualify? Disruptive Attributes Namespaces and XPath Expressions Referencing Other Namespaces Schemas for XML, XML Base and X Link Namespace Behaviour of Imported Components Importing Schemas with No Namespaces Chameleon Design Allowing Any Elements or Attributes from a Particular Namespace 11. Referencing Schemas and Schema Datatypes in XML Documents Associating Schemas with Instance Documents Defining Element Types Defining Nil (Null) Values Beware the Intrusive Nature of These Features 12. Creating More Building Blocks Using Object-Oriented Features Substitution Groups Controlling Derivations 13. Creating Extensible Schemas Extensible Schemas The Need for Open Schemas 14. Documenting Schemas Style Matters The W 3C XML Schema Annotation Element Foreign Attribute s XML 1.0 Comments Which One and What For?; 15. Elements Reference Guide; 16. Datatype Reference Guide; A. XML Schema Languages; B. Work in Progress.