XSL Concepts and Practical Use: Advanced Transformation Topics

Controlling Input Whitespace

XSLT has to handle whitespace in both the stylesheet and the source document in a reasonable and controllable way.

To deal with whitespace in the stylesheet, it employs the following rules:

If a text node contains non-whitespace characters, it is preserved
If a text node occurs inside <xsl:text> it is preserved
If the nearest ancestor xml:space attribute has the value preserve, it is preserved
Otherwise it is stripped (discarded from the tree before any transformation begins)

The rules for whitespace in the source document are the same, with the exception that you can specify the default stripping rules with <xsl:preserve-space> and <xsl:strip-space>:

If a text node contains non-whitespace characters, it is preserved
If a text node occurs inside an element listed in <xsl:preserve-space>, it is preserved
If the nearest ancestor xml:space attribute has the value preserve, it is preserved
Otherwise it is stripped (discarded from the tree before any transformation begins)