XPath and XPointer: Locating Content in XML Documents (Paperback)

~ John Simpson (Author)
Key Phrases: compound location path, plural body parts, final location step, The Twins, The Sea-Goat, Path Function Types (more...)

Editorial Reviews

Product Description

Referring to specific information inside an XML document is a little like finding a needle in a haystack: how do you differentiate the information you need from everything else? XPath and XPointer are two closely related languages that play a key role in XML processing by allowing developers to find these needles and manipulate embedded information. XPath describes a route for finding specific items by defining a path through the hierarchy of an XML document, abstracting only the information that's relevant for identifying the data. XPointer extends XPath to identify more complex parts of documents. Written for XML and XSLT developers and anyone else who needs to address information in XML documents, the book assumes a working knowledge of XML and XSLT. By the time you've finished the book, you'll know how to construct a full XPointer (one that uses an XPath location path to address document content) and completely understand both the XPath and XPointer features it uses.

About the Author

JOHN E. SIMPSON is a Distributed Systems Specialist with the City of Tallahassee, Florida, developing database and Web applications for the Public Works Department. He is the author of "Just XML," Second Edition (Prentice Hall PTR) and contributes the monthly "XML Q& A" column to XML.com, the Web's premier XML information site. Simpson has taught the popular "XML from the Ground Up" seminar on Geek Cruises to Alaska and the Caribbean. He recently assisted Microsoft in documenting the features and use of its standards-compliant XML and XSLT processor, MSXML.

Product Details

• Paperback: 208 pages
• Publisher: O'Reilly Media, Inc. (July 31, 2002)
• Language: English
• ISBN-10: 0596002912
• ISBN-13: 978-0596002916
• Product Dimensions: 9.1 x 6.9 x 0.5 inches
• Shipping Weight: 12.6 ounces (View shipping rates and policies)
• Average Customer Review: 3.7 out of 5 stars  See all reviews (7 customer reviews)
• Amazon.com Sales Rank: #132,986 in Books (See Bestsellers in Books)

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Customer Reviews

Most Helpful Customer Reviews

12 of 13 people found the following review helpful:

2.0 out of 5 stars The complexity of the book hides the simplicity of XPath, June 6, 2003

By	Roger (Sweden) - See all my reviews

O'Reilly books are usually a good choice for a professional to learn a concept in an effective way. However, this book is an exception. If you think XPath looks difficult, it is just because this book makes it _seem_ difficult. Read the official W3C specifikation instead and you will see how simple XPath really is.

The book incorporates a lot of discussions about XPath but they really get in the way of XPath, beeing presented the way they are. It would have been more effective if the book explained XPath just by including the 30 pages of XPath specification, and instead focused not on explaing, but on discussing aspects.

My main point is that you learn to use, as well as master, XPath an order of magnitude faster by reading the specification than by reading this book.

12 of 15 people found the following review helpful:

3.0 out of 5 stars Falls short in comparison with XSLT related books, February 2, 2003

By	Cees van Barneveldt (Grand Rapids, MI United States) - See all my reviews

From the back page of this book: "XPath and XPointer focuses directly on a critical topic that has been covered only briefly in other books". That is true as far as it goes for XPointer;however there are quite a number of XSLT books that explain XPath. That makes sense, because XPath is mainly used in the context of XSLT. (The other context is XPointer, but that is not official W3C recommendation yet, and will be much more limited in use.) That means that a book that deals almost exclusively with XPath should give a better and fuller treatment of XPath than most of the XSLT related books in order to have added value.

Quite frankly, I do not think that this book fulfills that promise. Chapter 2 "XPath Basics" fails to explain the theory behind XPath in a comprehensive manner, and is a tough read. What I am missing here is a clear explanation of how XPath relates to the DOM Model and XSLT processing model. Chapter 3 and 4 give a pretty decent explanation of how XPath expressions and functions work. The description is not complete however, I missed for instance an explanation of the key() function and element-available() function. What I also miss are the production rules of XPath. A more formal approach, with assistance of the official W3C recommendation, would have given a much completer explanation of XPath. Why was't the official W3C recommendation included via an appendix? Chapter 5 "XML in Action" is solely dedicated to examples. Very useful and clear. Chapter 6 "XPath 2.0" talks about how future XPath specifications are developing. Which is interesting of course, but by it's very nature speculative.

Chapter 7 thru 9 try to explain XPointer. These chapters fail completely for a number of reasons:
a) XPointer is not an official recommendation yet, so the authors are shooting at a moving target
b) XPointer will mainly be used together with XLink, which is not explained in this book
c) I found the explanation incomprehensible.

My advice would be to skip this book and buy a good XSLT book that also covers XPath instead, such as the XSLT Programmer's Reference from Michael Kay.

5 of 6 people found the following review helpful:

4.0 out of 5 stars easy to understand, written with humour reference manual, February 3, 2003

By	Boris Aleksandrovsky (San Francisco, CA United States) - See all my reviews

John E. Simpson has done a remarkable job in elucidating yet another XML-related techology in fun and easy small book. Care is taken to provide comprehensive examples (sometimes with hacker-type tougue-in-cheek approach) which illustrates the points of syntax. One does not need to read the book in comprehensive fashion, after a few chapters, you one can just start coding and refer to the rest as a reference manual.

One thing, however is missing, the book does you why you should use XPath or XPointer. What are the real world examples and applications? And what about XQuery? How is XPath related to XSLT? Those points are left for the reader to ponder about, and this is the only reason I am not giving the book 5 starts.