XSLT Empty Tags

Question

Say I have a very simple XML with an empty tag 'B':

<Root>
  <A>foo</A>
  <B></B>
  <C>bar</C>
</Root>

I'm currently using XSLT to remove a few tags, like 'C' for example:

<?xml version="1.0" ?>

<xsl:stylesheet version="2.0" xmlns="http://www.w3.org/1999/XSL/Transform" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"&gt;

<xsl:output method="xml" indent="no" encoding="utf-8" omit-xml-declaration="yes" />

<xsl:template match="*">
 <xsl:copy>
  <xsl:copy-of select="@*" />
  <xsl:apply-templates />
 </xsl:copy>
</xsl:template>

<xsl:template match="C" />

</xsl:stylesheet>

So far OK, but the problem is I end up having an output like this:

<Root>
  <A>foo</A>
  <B/>
</Root>

when I actually really want:

<Root>
  <A>foo</A>
  <B></B>
</Root>

Is there a way to prevent 'B' from collapsing?

Thanks.

Answer 1

No. The 2 are syntactically identical, so you shouldn't have to worry

Answer 2

There is no standard way, as they are equivalent; You might be able to find an XSLT engine that has an option for this behaviour, but I'm not aware of any.

If you're passing this to a third party that cannot accept empty tags using this syntax, then you may have to post-process the output yourself (or convince the third party to fix their XML parsing)

Answer 3

It is up to the XSLT engine to decide how the XML tag is rendered, because a parser should see no difference between the two variations. However, when outputting HTML this is a common problem (for <textarea> and <script> tags for example.) The simplest (but ugly) solution is to add a single whitespace inside the tag (this does change the meaning of the tag slightly though.)

Answer 4

It should not be a problem if it is or . However if you are using another tool which expects empty XML tags as way only, then you have a problem. A not very elegant way to do this will be adding a space between staring and ending 'B' tags through XSLT code.

Answer 5

Ok, so here what worked for me:

<xsl:output method="html">

Thank you all for your help :-)

Answer 6

<xsl:text disable-output-escaping="yes">
<![CDATA[<div></div>]]>
</xsl:text>

This works fine with C#'s XslCompiledTransform class with .Net 2.0, but may very well fail almost anywhere else. Do not use unless you are programmatically doing the transofrm yourself; it is not portable at all.

Answer 7

This has been a long time issue and I finally made it work with a simple solution. Add <xsl:text/> if you have a space character. I added a space in my helper class. <xsl:choose> <xsl:when test="$textAreaValue=' '"> <xsl:text/> </xsl:when> <xsl:otherwise> <xsl:value-of select="$textAreaValue"/> </xsl:otherwise> </xsl:choose>