How to use `xsl:include` with apache fop

Question

I use apache FOP to generate pdf files. I have this xsl code

<xsl:stylesheet version="1.0"
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:fo="http://www.w3.org/1999/XSL/Format">
  <xsl:output method="xml" indent="yes" />
  <xsl:template match="/">
    <fo:root font-size="11pt" font-family="serif">
      <fo:layout-master-set>
        <fo:simple-page-master master-name="A4-portrait"
          page-height="29.7cm" page-width="21.0cm" margin-top="1cm"
          margin-left="1.5cm" margin-right="1cm" margin-bottom="1cm">
          <fo:region-body />
          <fo:region-after region-name="footer" extent="15mm"/>
        </fo:simple-page-master>
        <fo:simple-page-master master-name="A4-landscape"
          page-width="29.7cm" page-height="21.0cm" margin-top="1cm"
          margin-left="1cm" margin-right="1cm" margin-bottom="1cm">
          <fo:region-body />
          <fo:region-after region-name="footer2" display-align="after" extent="0cm"/>
        </fo:simple-page-master>
      </fo:layout-master-set>
      <fo:page-sequence master-reference="A4-portrait">
        <xsl:include href="footer_common.xsl"/>
        <fo:flow flow-name="xsl-region-body">
          ....
        </fo:flow>
      </fo:page-sequence>
    </fo:root>
  </xsl:template>
</xsl:stylesheet>

Notice the element <xsl:include href="footer_common.xsl"/> The inclusion does not work! And here is footer_common.xsl:

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:fo="http://www.w3.org/1999/XSL/Format"
     version="1.0">
  <fo:static-content flow-name="footer" font-size="7pt">
    <fo:table>
      <fo:table-column column-width="70mm"/>
      <fo:table-column column-width="70mm"/>
      <fo:table-column column-width="70mm"/>
      <fo:table-body>
        ...........
      </fo:table-body>
    </fo:table>
  </fo:static-content>
</xsl:stylesheet>

Both .xsl files are in the same resource directory. If it matters - I use eclipse for development. In my java code I get the main .xsl file as a resource stream and use it for the transformation.

The error message is xsl:include ist an dieser Position in der Formatvorlage nicht zulässig! which means, xsl:include is not allowed at that position in the template

Can anyone see what I am doing wrong?

Thanks for any help or hints.

Answer 1

xsl:include is a top-level element (actually, a stylesheet declaration), which means that it may only appear as an immediate child of xsl:stylesheet. So, you simply cannot include a stylesheet from within an fo:page-sequence element.

But I think you're not in need of xsl:include and a separate stylesheet, but of xsl:call-template and a separate named template.

Write a separate template similar to the following:

<xsl:template name="footer-ebase">
  <fo:static-content flow-name="footer" font-size="7pt">
    <fo:table>
      <fo:table-column column-width="70mm"/>
      <fo:table-column column-width="70mm"/>
      <fo:table-column column-width="70mm"/>
      <fo:table-body>
        <!--...-->
      </fo:table-body>
    </fo:table>
  </fo:static-content>
</xsl:template>

In the main template (the place where you'd like to insert content), reference the named template with:

<fo:page-sequence master-reference="A4-portrait">
    <xsl:call-template name="footer-ebase"/>
    <fo:flow flow-name="xsl-region-body">
    <!--...-->
    </fo:flow>
</fo:page-sequence>

---

Note that it does not always make sense to write named templates. It is advisable if

• your code would otherwise be redundant because you need the same functionality in several places
• the code would clutter the template and make it hard to read
• you use recursion to solve a problem

If you want to split content into separate templates for no apparent reason, then you'd best do away with it alltogether.

You can still put the named template into a separate stylesheet if you wish, but then you need to use xsl:include as a top-level element:

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" >
    <xsl:include href="footer-ebase.xsl"/>
    <!--...-->
</xsl:stylesheet>