I made a template for replacing strings with translated value using
the lookup table. The lookup table is included in the template, so I
can access it with
document('')

But since there usually over 10 strings that have to be translated on
a single page, I think it's not efficient to call document('') 10
times.

Is there a way to copy the value of document('')/*/trans:tr to a
variable and then access that variable 10 times?
Can a variable hold the node set?
Would this make sense?

Sure:
  <xsl:variable name="trs" select="document('')/*/trans:tr"/>

If yes, then how can I change this template? By the way, this template
is not completely finished yet, I still have to put
a real test condition instead of testing for true()

    <xsl:template name="translateString">
        <xsl:param name="str"/>
        <xsl:param name="toLang"/>
        <xsl:param name="fallback" select="'en'"/>
		
        <xsl:choose>
            <xsl:when test="true()">
                <!-- <xsl:value-of select="$fallback"/> -->
				<xsl:value-of
select="document('')/*/trans:tr/tr_string[@str=$str]/*[name()=$toLang]"/>

	Martin Honnen
	http://msmvps.com/blogs/martin_honnen/