How to Render styles like font color and size which is present inside a span tag in xslt using xsl-fo?

I am generating pdf files based on the output from a rich text editor, some of the components like font color, font size for a specific word or a paragraph comes like

 <p>Hello Hi <strong>skansdjnsjc</strong>
 <span style="color:#ce181e"><em>cddsklncjkdsv</em></span>
 <span style="color:#ce181e">sdsadsad</span></p>

And in my xslt file I did a template match like

  <xsl:template match="span">     
    <xsl:variable name="color">
     <xsl:choose>
       <xsl:when test="@color">
         <xsl:value-of select="@color"/>
       </xsl:when>
       <xsl:otherwise>
         <xsl:text>black</xsl:text>
       </xsl:otherwise>
    </xsl:choose>
 </xsl:variable>
 </xsl:template>

But the required styles are not being rendered in the pdf file. Am I missing anything? or is there any solution to it.

Thanks For the help in advance !!!

Solution

In XSLT 2.0, you could extract the color from the style attribute like so

<xsl:variable name="extractColor" select="tokenize(tokenize(@style, ';')[normalize-space(substring-before(., ':')) = 'color'], ':')[2]" />

Then, to set your color variable (setting it to black if no color was extracted), do this....

<xsl:variable name="color" select="($extractColor, 'black')[1]" />

Of course, if you extended to extract other values, you could create a function.

Try this XSLT

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="2.0" xmlns:my="my">
  <xsl:output method="html" indent="yes" html-version="5"/>

  <xsl:template match="span">
    <span>
        <xsl:variable name="color" select="(my:extract(@style, 'color'), 'black')[1]" />
        <xsl:value-of select="$color" />
    </span>
  </xsl:template>

  <xsl:function name="my:extract">
      <xsl:param name="text" />
      <xsl:param name="name" />
      <xsl:sequence select="tokenize(tokenize($text, ';')[normalize-space(substring-before(., ':')) = $name], ':')[2]" />
  </xsl:function>
</xsl:stylesheet>