Learning XML, 2nd Edition

Formatting

Since XSLT was originally intended for producing human-readable formatted documents, and not just as a general transformation tool, it comes with a decent supply of formatting capabilities.

Setting the Output Mode

A global setting you may want to include in your stylesheet is the <output> element. It controls how the XSLT engine constructs the result tree by forcing start and end tags, handling whitespace in a certain way, and so on. It is a top-level element that should reside outside of any template.

Three choices are provided: XML, HTML, and text. The default output type, XML, is simple: whitespace and predefined entities are handled exactly the same in the result tree as in the input tree, so there are no surprises when you look at the output. If your result document will be an application of XML, place this directive in your stylesheet:

<xsl:output method="xml"/>

HTML is a special case necessary for older browsers that do not understand some of the new syntax required by XML. It is unlikely you will need to use this mode instead of XML (for XHTML); nevertheless it is here if you need it. The exact output conforms to HTML version 4.0. Empty elements will not contain a slash at the end and processing instructions will contain only one question mark. So in this mode, the XSLT engine will not generate well-formed XML.

Text mode is useful for generating non-XML output. For example, you may want to dump a document to plain text with all the tags stripped out. Or you may ...