XML Schemas [Paperback]

Lucinda Dykes (Author), Ed Tittel (Author), Chelsea Valentine (Author)

Book Description

Publication Date: January 18, 2002

XML Schemas are a more precise way to model data with XML and are an update to the old XML DTDS. The final spec was approved in May by the W3C standards organization and is one of the hottest areas in XML programming. Just as the discovery of the Rosetta stone provided a way to establish the meaning of Egyptian hieroglyphics, XML schemas provide a way for organizations to establish the meaning of XML documents so they can be understood across different company systems. Each industry will have a set of shared vocabularies for describing data being exchanged across the Web, making schemas a cornerstone of e-commerce development.

Editorial Reviews

From the Back Cover

Whether it is used for web development, creating documentation, or exchanging data between business partners, XML continues to grow in importance as a highly flexible document-design and data-modeling tool. Despite the limitations of using SGML Document Type Definitions (DTDs) to define document structures, XML has made inroads wherever data must flow among disparate platforms. The Schema specification has achieved W3C recommendation status, providing an alternative to DTDs that enables you to precisely structure XML data. But using the Schema Language does more than provide a more powerful way of defining data; it's also a better way because it uses XML's structure, syntax, and namespaces, instead of those derived from the complex SGML.

XML Schemas introduces you to this elegant new technology, which brings the power of data modeling and data structuring to XML. A truly practical book has to give you more than just the details on syntax and semantics, examples of constructs and datatypes, and instruction in standard procedures. You get all that, but you'll also find lots of expert tips and techniques for document modeling, all reinforced with practical, real-world examples.

Even as you're discovering the advantages of XML Schema, you'll learn about the continuing use of DTDs. In some situations--when designing document-oriented XML, for example--DTDs might still be the way to go. You'll learn about visual XML Schema tools, but you'll also see how setting out armed with just a text editor gives you insights you might not acquire otherwise. It won't be long before you're developing your own XML Schema documents, using the power of XML to structure data for seamless, cross-platform exchange.

About the Author

Valentine is the author of more than a dozen books on markup languages from HTML to XML, including numerous "For Dummies" titles on HTML, XHTML, and

Product Details

• Paperback: 656 pages
• Publisher: Sybex Inc; 1st edition (January 18, 2002)
• Language: English
• ISBN-10: 0782140459
• ISBN-13: 978-0782140453
• Product Dimensions: 9 x 7.6 x 1.5 inches
• Shipping Weight: 2.5 pounds
• Average Customer Review: 4.0 out of 5 stars  See all reviews (1 customer review)
• Amazon Best Sellers Rank: #1,172,606 in Books (See Top 100 in Books)

Customer Reviews

Most Helpful Customer Reviews

9 of 9 people found the following review helpful:

4.0 out of 5 stars Helpful, but ..., January 6, 2006

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wiredweird "wiredweird" (Earth, or somewhere nearby) - See all my reviews
(HALL OF FAME REVIEWER)    (TOP 500 REVIEWER)   

This review is from: XML Schemas (Paperback)

I wanted a quick transition from XML DTDs to schemas when I picked up this book. As it turned out, I chose better than I knew. This isn't just a book about the W3C standard XML schemas, it specifically addresses the developer making the transition from DTDs. And, despite what you might guess from the title, it acknowledges that DTDs still have a place in the world of schemas.

After its attention to DTDs and their schema counterparts, this book's big strength is in numerous and detailed examples. Every construct is shown real code samples, often in multiple samples. That certainly helps the cut&paste coder. It's also good for the more thoughtful programmer, one trying to pick up good development style as well as the basics of syntax and semantics.

The authors become overly dependent on the examples, however. Again and again, they introduce some new aspect of schema development, offer a few examples, then stop. Although the reader now knows how say the new words in grammatically correct ways, she is left with no definition of just what those words mean. As an example, the "collapse" value of the "whiteSpace" facet is introduced on p.138 (even though the index says p.137), but not defined for another 400 pages. Namespaces are presented similarly and used pervasively, but their real purpose is illustrated poorly if at all: they allow the same element name to be imported from different schema fragments, but used in unambiguously different ways. In other places, two slightly different code fragments are used to ilustrate some distinction. In discussing "definition" vs. "declaration," for example, the differences are so small that finding them becomes a "where's Waldo" exercise that just a little typographic enhancement could have clarified.

Attention to detail faltered in other ways, too. A few places omit closing delimiters: opening "<" sometimes lacked matching ">", and ditto quote marks. ISBNs appear repeatedly in examples, but are generally described as 10-digit numbers. Only a late example imported from another source acknowledges that the letter X may appear in the last position. Examples with addresses, phone numbers, and postal codes show no awareness of internationalization issues, or even of American conventions like apartment numbers in street addresses, PO boxes, and APO addresses. The cautious reader should study their XML and schema usage, but eye the application content in the most critical way. Also, as noted above, indexing could have been a lot more helpful.

Still, it's user-friendly introduction to the complexities of XML schemas. It addresses the common case of a developer moving from DTDs to schemas, without the impenetrable density of the W3C standards. It also mentions some of the competing mechanisms, including Oasis's RELAX. The book has flaws, and could have in-lined a little discussion of XPath and regular expressions instead of pointing to standards, but generally stands well by itself. There may be better references out there, but this one should get you started.

//wiredweird