Calling templates with (defaulted) params

Hi, 

in an XSLT that processes an XML description to produce HTML,
I would like to be able to define any number of small "rendering"
templates 
for logical elements that I wish to define. To make the templates
reusable,
they are parametrized. The question is the number of parameters may be
long, and having to state a value for each one each time the template is
called is not convenient. Is it possible to reduce overheaviness (i.e.
not replace
it by something just as heavy somewhere else in the code ;-) by having 
each template decide default values for each parameter, and uses it in
each 
case a parameter is not specified ?

In the small example below, imagine a logical "section", represented by
the <icm key="Section">, and a single param. This is processed by the 
proposed XSLT, to call a template called "Section" that expects 2
params.
Imagine that the non-specified param should assume some value, 
e.g. 'no value for note heading!'. Two ways of calling the template
"Section"
are included below, one with no defaults, and one with defaults, which
is significantly heavier (and this is an example with only 2 params!).

My question is, are there other lighter ways to do this in XSLT?
Any improvements anyone can suggest? 
Any optimization should be in favour of many such templates, each 
with possibly many parameters. And, any shortcuts should also favour
the source xml description rather than the xsl that processes it.  

tia, and best regards, 

Mario Ruggier


==== xml source ====
...
<icm key="Section">
        <param name="heading" value="Section Heading" />
        ....
</icm>
...


===== xsl source ====

<xsl:output method="html" indent="yes" />

<!-- icm template wrapper to call templates according to @key value -->
<xsl:template match="icm">
  <xsl:variable name="icm-key" select="@key" />
  <xsl:choose>
    ....
    <xsl:when test="$icm-key='Section'">

      <!-- no defaulting... --> 
      <xsl:call-template name="Section" >
        <xsl:with-param name="heading"
select="param[@name='heading']/@value" />
        <xsl:with-param name="headingNote"
select="param[@name='headingNote']/@value" />
       </xsl:call-template>

      <!-- with defaulting... --> 
      <xsl:call-template name="Section" >
         <xsl:with-param name="heading">
            <xsl:call-template name="get-defaulted-value">
                <xsl:with-param name="proposed-value"
select="param[@name='heading']/@value" />
                <xsl:with-param name="default-value" select="'no value
for heading!'" />
            </xsl:call-template>
         </xsl:with-param>
         <xsl:with-param name="headingNote" 
           <xsl:call-template name="get-defaulted-value">
                <xsl:with-param name="proposed-value"
select="param[@name='headingNote']/@value" />
                <xsl:with-param name="default-value" select="'no value
for heading note!'" />
            </xsl:call-template>
         </xsl:with-param>
       </xsl:call-template>

    </xsl:when>
    ...
  </xsl:choose>
</xsl:template>

... <!-- other templates .--> 

<xsl:template name="Section" >
  <xsl:param name="heading" />
  <xsl:param name="headingNote" />
    <table border="0" cellspacing="2" cellpadding="2" >
      <tr valign="top" align="left">
        <th bgcolor="#99ffff"><xsl:value-of select="$heading" /></th>
        <td><xsl:value-of select="$headingNote" /></td>
      </tr>
      <xsl:apply-templates />
    </table>
</xsl:template>

... 

<!-- "defaulting" function --> 
<xsl:template name="get-defaulted-value">
  <xsl:param name="proposed-value" />
  <xsl:param name="default-value" />
  <xsl:choose>
    <xsl:when test="$proposed-value"><xsl:value-of
select="$proposed-value" /></xsl:when>
    <xsl:otherwise><xsl:value-of select="$default-value"
/></xsl:otherwise>
  </xsl:choose>
</xsl:template>


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