Sams Teach Yourself XML in 21 Days

By Steven Holzner

• Table of Contents
  • About the Author
  • Acknowledgments
  • We Want to Hear from You!
  • Introduction
  • Part I: At a Glance
  • Day 1. Welcome to XML
  • Day 2. Creating XML Documents
  • Day 3. Creating Well-Formed XML Documents
    • What Makes an XML Document Well-Formed?
    • Creating an Example XML Document
    • Understanding the Well-Formedness Constraints
    • Using XML Namespaces
    • Understanding XML Infosets
    • Understanding Canonical XML
    • Summary
    • Q&A
    • Workshop
  • Day 4. Creating Valid XML Documents: DTDs
  • Declaring Attributes in DTDs
  • Day 6. Creating Valid XML Documents: XML Schemas
  • Day 7. Creating Types in XML Schemas
  • Part I. In Review
  • Day 8. Formatting XML by Using Cascading Style Sheets
  • Day 9. Formatting XML by Using XSLT
  • Day 10. Working with XSL Formatting Objects
  • Part II. In Review
  • Part III: At a Glance
  • Day 11. Extending HTML with XHTML
  • Day 12. Putting XHTML to Work
  • Day 13. Creating Graphics and Multimedia: SVG and SMIL
  • Day 14. Handling XLinks, XPointers, and XForms
  • Part III. In Review
  • Part IV: At a Glance
  • Day 15. Using JavaScript and XML
  • Day 16. Using Java and .NET: DOM
  • Day 17. Using Java and .NET: SAX
  • Day 18. Working with SOAP and RDF
  • Part IV. In Review
  • Part V: At a Glance
  • Day 19. Handling XML Data Binding
  • Day 20. Working with XML and Databases
  • Day 21. Handling XML in .NET
  • Part V. In Review
  • Appendix A. Quiz Answers

Q&A

1. Can I use an XML validator to test an XML document's well-formedness?

   Yes, if you have a DTD or XML schema for the document—an XML validator will also report whether the document is well-formed or not. However, you do need a DTD or XML schema if you want to use a validator—very few will check a document without one. One program that will check an XML document's well-formedness without a DTD or XML schema is Internet Explorer. If the document is not well-formed, you'll see the message "The XML page cannot be displayed", and Internet Explorer will tell you the exact problem with the document.

2. Do I need to use namespaces if there's no chance of tag name conflicts with other XML applications?

   Often, yes. Namespaces aren't used solely to avoid tag (and attribute) name conflicts—using a namespace also indicates to an XML processor what XML application you're using. For example, if you're using MathML, you must use the current MathML namespace or most MathML-enabled XML processors will complain.

Share This