XSLT and XQuery 2017



XML makes it possible to store content in a standardized format that can be converted to a variety of output media using a broad choice of technologies. Most of these technologies build on related W3C standards with both commercial and open source tools support. XSLT lets you define a transformation of a set of documents into a particular format, so that three XSLT stylesheets could create published products from the same content for three different media. The XQuery language lets you pull subsets of XML content from huge repositories, so that XML databases that support XQuery can (among other things) provide dynamic publications customized for different customers.

Because the "Hands-on Introduction to XML" course provides introductory material on XSLT and XQuery, classes in this course are more advanced and focus on helping existing XSLT and/or XQuery developers get the most out of their code and their development time. Intermediate XSLT developers looking for more hands-on material should consider the Hands-on Digital Publishing course.

This course is chaired by Priscilla Walmsley and taught by Adam Retter, Florent Georges, Michael Kay, and Priscilla Walmsley.

Classes for 2017

The XSLT and XQuery course runs on and .

Refactoring XSLT

Taught by Priscilla Walmsley.

A lot of existing XSLT stylesheets are not optimal. They may be performing poorly, hard to maintain, or not robust enough to handle all use cases. There are many reasons for this: they might have been developed under time constraints, built up gradually over time into something overly complex, written by less experienced developers, or generated from a tool.

In this class, we will take a look at what constitutes a well-designed XSLT stylesheet, and how to apply good design techniques to existing XSLT stylesheets to make them more robust and easier to maintain. We will talk about the pitfalls that developers new to XSLT encounter that could cause problems later on, and how to spot them. We will look at tools to identify potential stylesheet weaknesses and automate some of the cleanup.

As a group, we will examine specific examples of XSLT stylesheets and discuss how to improve them. Students are encouraged to submit XSLT examples that can be used for this discussion, in order to get constructive feedback.

Querying XML Databases with XQuery

Taught by Adam Retter.

This class will provide an overview of the capabilities and use cases of XML databases, examining some of the database products that support XML and how they are being used. It will then cover the role of XQuery among other XML technologies in the querying of XML databases.

As a group, the class will build a simple search application using XQuery and an XML database (eXist). This will provide an opportunity for attendees to learn the syntax and capabilities of XQuery, as well as see it in action. Major features of the XQuery language such as FLWOR expressions, XML constructors, and user-defined functions will be explained.

XSLT and XQuery Performance Workshop

Taught by Michael Kay.

Run-time performance isn’t always your most important objective, but sometimes getting performance right can be critical to the project. This session will be a performance workshop: we’ll look at the methodology, techniques, and tools that you can use to ensure your XSLT or XQuery code (and your XML application in general) meets its performance requirements. This will be an interactive session where we’ll explore different ideas by trying them out and measuring the effect. If you’re planning to come, consider whether you have any material that we could study during the workshop, and if so, let us know in advance: if the problems we tackle come from real life, we will all learn more than if we use a textbook exercise. Also think about whether there are any burning questions you want answered (a couple of years ago, we studied the effect of schema-awareness on transformation time, for example — this year it might be streaming or parallel processing).

XSLT 3.0 and XQuery 3.0

Taught by Florent Georges.

XSLT 3.0 and XQuery 3.0 come with a lot of new, powerful features.

XPath 3.0 itself comes with one of the most useful of them: function items and higher-order functions; that is, the ability to manipulate functions and pass them around, calling them dynamically and define new anonymous inline functions. XQuery 3.0 has numerous additions on its own, among them grouping, windowing, try/catch, and private functions. For XSLT 3.0, the biggest addition is the support for streaming transformation. Florent will also introduce the packages, the evaluation of dynamically computed XPath expressions, the extension of template rules to atomic values, the try/catch mechanism and the new xsl:assert instruction.