How to check if an XML node contains text

Question

How can I check if a XML node contains text, or only empty nodes?

Example: Let's say we have the following XML:

<text>
   <p> </p>
   <p> </p>
</text>

(Note the whitespace between the p tags)

In a different XML, we have the following XML:

<text>
   <p>Hello World!</p>
</text>

I'd like the test to pass in the second example, but not in the first, as the second example contains text, but the first contains empty nodes.

Is there a way to easily achieve this?

(I use XSLT 2.0.)

Answer 1

I think normalize-space does what you want, e.g. this will 'pass':

<xsl:if test="normalize-space(/text/p) != ''">
    ...
</xsl:if>

normalize-space will trim all leading and trailing whitespace from a string, which will leave text behind in your second example, but remove all characters in your first example allowing you to compare against the empty string ''.

Note it also compresses multiple whitespace characters in sequence into a single character, so for example hello<space><space><space>there would become hello<space>there.

http://www.w3.org/TR/xpath/#function-normalize-space (XPath 1)

Answer 2

Use:

p[normalize-space()]

This selects any p child of the context (current) node, whose string-value is not the empty string or a whitespace-only string.