Sams Teach Yourself XML in 21 Days
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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
- 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
Day 4. Creating Valid XML Documents: DTDs
The past couple days have prepared you for what's coming up now—the creation of valid XML documents. Unlike with HTML, where a browser can check HTML because it knows all about legal HTML, you create your own markup in XML, which means that an XML processor can't check your markup unless you let it know how to. In XML, you define what's legal and what's not by specifying the syntax you're going to allow for an XML document. There are two ways to validate XML documents—with document type definitions (DTDs) and with XML schemas. Today and tomorrow cover DTDs, and Days 6, "Creating Valid XML Documents: XML Schemas," and 7, "Creating Your Own Types in XML Schemas," cover XML schemas.
Here's an overview of today's topics:
- Creating DTDs
- Using validators
- Declaring elements
- Using ANY to allow any content
- Declaring child elements
- Declaring parsed character data
- Creating child sequences
- Using DTD choices
- Using internal and external DTDs
- Using DTDs and namespaces
DTDs provided the original way to validate XML documents, and the syntax for DTDs is built right in to the XML 1.0 specification. Tons of XML processors out there use DTDs in XML documents, and DTDs are the first step in any discussion on validation. But it's also true that DTDs are limited compared to XML schemas, and with the vast support Microsoft is pouring into XML schemas, schemas are really taking off these days. The details on schemas are provided on Days 6 and 7.
All About DTDs | Next Section
