<xsl:call-template name="fo-external-image"> returns error ':1:1: Content is not allowed in prolog'

["Jörg Möbius" <joerg.moebius@hamburg.de>]

Hi,
I solved the problem so this is just to inform/discuss.

My issue was/is to place a graphic within the page header. I am using FOP
('fop.extensions' is not set) in an eclipse environment. When I have to
reference files I try to use only relative paths like
'figures/xsdtrans-logo-small.gif'.
 
According Chapter 12. Print customizations/../Graphic in header or footer) I
tried to do within 
my customizing layer with 

<xsl:when test="($sequence='odd' or $sequence='even') and $position='left'">
  <xsl:if test="$pageclass != 'titlepage'">
    <fo:external-graphic content-height="30%">
      <xsl:attribute name="src">
        <xsl:call-template name="fo-external-image">
          <xsl:with-param name="filename"
select="figures/xsdtrans-logo-small.gif"/>
        </xsl:call-template>
      </xsl:attribute>
    </fo:external-graphic>                
  </xsl:if>
</xsl:when>

and FOP aborted processing with error: ':1:1: Content is not allowed in
prolog'

When I do without <xsl:call-template name="fo-external-image"> like 

<xsl:when test="($sequence='odd' or $sequence='even') and $position='left'">
  <xsl:if test="$pageclass != 'titlepage'">
    <fo:external-graphic content-height="30%">
      <xsl:attribute name="src">
        figures/xsdtrans-logo-small.gif
      </xsl:attribute>
    </fo:external-graphic>                
  </xsl:if>
</xsl:when>

I get the intended result.

Casting a glance at <xsl:call-template name="fo-external-image"> it seems
that - without using processor extensions - the template expects the
filename in a valid url-format.

Regards

Joerg Moebius