Level: Intermediate James R. Fuller (jim.fuller@webcomposite.com), Technical Director, FlameDigital Limited & Webcomposite s.r.o.
30 Sep 2008 The XQuery specification is well over a year old now. A surfeit of solid
implementations combined with (if developer chatter is anything to go by) marked new
interest, seems to indicate that XQuery is finally experiencing higher adoption rates.
Possibly this is due to developers starting to figure out how to utilize XQuery within
a rich mixture of XML technologies (such as XML databases. XSLT, XML Schema). Learn how to use XQuery beyond its original role as an XML query language and apply it toward the development of middleware and Web applications.
In this tutorial
This tutorial is about using XQuery to develop applications and middleware. It outlines
some of XQuery's limitations while you develop applications, gives you practical
advice along the way on how to manage these limitations as well as highlights where
XQuery makes it easy or difficult. The bulk of the tutorial then builds on these
principles, as it presents a series of programmatic idioms commonly found in application development: - Use of extension functions
- Unit testing and assertions
- Recursion and sorting
- Higher-order functions
Each section comes with accompanying source code examples.
Prerequisites
This tutorial is written for developers who have a general familiarity with XML
technologies as well as some cursory XSLT or Query experience. The programmatic idioms
presented can be found in one form or another in a lot of computer programming
languages, and I make no claim of invention on them. This re-use should mean that for
most readers, you'll see familiar constructions—albeit set in the context of XQuery programming.
System requirements
You will need JavaScript enabled in your browser. You must install Michael Kay's Saxon XSLT and
XQuery processor SA aware version to execute code examples. As you need the Saxon-SA
version, you must register for a 30-day trial (for example, at the time of this
writing version 9.1SA was used in testing). Many of the code examples use higher-order
functions to take advantage of specific Saxon-SA extension functions (specifically, the saxon:function()). Place all the Java™ Archive (JAR) files and license file in Saxon under the /lib directory. To run examples you can invoke Saxon from the command line or use the included Ant
build file (which I used to test the code examples). If you do use the build file,
then you should also install the latest Apache Ant, and take care to amend the saxon.lib.dir property to point to the /lib directory containing
Saxon JARs. To test whether Saxon is working properly, run the Ant target checkSaxon, which will successfully process when Saxon is installed properly. All Ant targets generate result output into the /result directory.
Duration
1 hour
Formats html, pdf
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