hyphenation character in xslt attribute (xsl-fo) - xslt

Question

I think it's a very simple question. But although I build very fancy xslt transformation, this simple one cannot be solved by me.
The problem is:
I want to add attributes to xsl-fo nodes, depending on xml data. These attributes have often a hyphen in it. How can I add these with an xslt transformation where xsl:attributes doesn't like the hyphenation character.
In a xml node I have got two attributes (name and value)
Example: name="font_size", value="7pt"
<Report>
<text content="I am a text">
<blockFormat name="font_size" value="7pt" />
</text>
</Report>
(I understand this is not wanted because you want to work with styles etceters. It's just an example with a simplified problem)
Now I want to make a xsl-fo block, and I want to place that attributes in the block element by using the xsl-function xsl:attribute
<fo:block>
<attribute name="{replace(#name,'_','-')}" select="#value" />
....
</fo:block>
goal to achieve after transformation
<fo:block font-size="7pt">
....
</fo:block
It doesn't function and I think this is because in xslt I can't put an hyphen in the attribute name, but in the fo-attribute it is needed.
Is there a way to use the xsl:attribute function for this?
And when not, what kind of working around do you suggest.
Thank you for helping!!!!

Answer 1

There are 1000 ways to do it, here is one (I didn't do anything with your Report element):
Input:
<Report>
<text content="I am a text">
<blockFormat name="font_size" value="7pt" />
</text>
</Report>
XSL:
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:fo="http://www.w3.org/1999/XSL/Format"
version="1.0">
<xsl:template match="Report">
<xsl:copy>
<xsl:apply-templates/>
</xsl:copy>
</xsl:template>
<xsl:template match="text">
<fo:block>
<xsl:apply-templates select="blockFormat/#*"/>
<xsl:value-of select="#content"/>
</fo:block>
</xsl:template>
<xsl:template match="#name">
<xsl:attribute name="{translate(.,'_','-')}">
<xsl:value-of select="ancestor::blockFormat/#value"/>
</xsl:attribute>
</xsl:template>
<xsl:template match="#value"/>
</xsl:stylesheet>
Output:
<Report>
<fo:block xmlns:fo="http://www.w3.org/1999/XSL/Format" font-size="7pt">I am a text</fo:block>
</Report>

Answer 2

Use #select instead of #value:
<fo:block>
<attribute name="{replace(#name,'_','-')}" select="#value" />
....
</fo:block>
See https://www.w3.org/TR/xslt20/#creating-attributes
Also, you need to be using XSLT 2.0 or 3.0 to use #select. If you're using XSLT 1.0, you'd have to do it as xsl:attribute/xsl:value-of/#select.
(It would also have helped understanding of your problem if you'd also shown the wrong result that you were getting.)