I thought it was strangely difficult to find a good XSLT document for creating a standard expanding left menu for the web site. This menu keeps the home page in the same level as the first sub level and always in the top row. Only levels in the "active" sub-tree are exposed and folding/unfolding only occurs while navigating.
Here is the xslt:
<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet
version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:msxml="urn:schemas-microsoft-com:xslt"
xmlns:umbraco.library="urn:umbraco.library"
exclude-result-prefixes="msxml umbraco.library">
<xsl:output method="html"/>
<xsl:param name="currentPage"/>
<xsl:template match="/">
<div id="navigationmenu">
<xsl:call-template name="drawNodes">
<xsl:with-param name="current" select="$currentPage/ancestor-or-self::node [@level=1]"/>
<xsl:with-param name="level" select="1"/>
<xsl:with-param name="openpage" select="$currentPage"/>
</xsl:call-template>
</div>
</xsl:template>
<xsl:template name="drawNodes">
<xsl:param name="current"/>
<xsl:param name="openpage"/>
<xsl:param name="level"/>
<xsl:param name="active">
<xsl:choose>
<xsl:when test="count($openpage/ancestor-or-self::node) > 0">
<xsl:call-template name="isInSubmenu">
<xsl:with-param name="list" select="$openpage/ancestor-or-self::node"/>
<xsl:with-param name="pos" select="1"/>
<xsl:with-param name="curpagename" select="$current/@id"/>
</xsl:call-template>
</xsl:when>
<xsl:otherwise>
1
</xsl:otherwise>
</xsl:choose>
</xsl:param>
<xsl:if test="$active=1">
<ul class="menu">
<xsl:if test="$level = 1">
<li class="menu level1">
<a href="/" class="menu">Home Page</a>
</li>
</xsl:if>
<xsl:for-each select="$current/node [string(data [@alias='umbracoNaviHide']) != '1']">
<li class="menu level{$level}">
<xsl:choose>
<xsl:when test="@id=$openpage/@id">
<a href="{umbraco.library:NiceUrl(@id)}" class="menu selected">
<xsl:value-of select="@nodeName"/>
</a>
</xsl:when>
<xsl:otherwise>
<a href="{umbraco.library:NiceUrl(@id)}" class="menu">
<xsl:value-of select="@nodeName"/>
</a>
</xsl:otherwise>
</xsl:choose>
<xsl:call-template name="drawNodes">
<xsl:with-param name="current" select="."/>
<xsl:with-param name="openpage" select="$openpage"/>
<xsl:with-param name="level" select="$level + 1"/>
</xsl:call-template>
</li>
</xsl:for-each>
</ul>
</xsl:if>
</xsl:template>
<xsl:template name="isInSubmenu">
<xsl:param name="list"/>
<xsl:param name="pos"/>
<xsl:param name="curpagename"/>
<xsl:variable name="curitemname" select="$list[$pos]/@id"/>
<xsl:choose>
<xsl:when test="$curitemname != $curpagename">
<xsl:choose>
<xsl:when test="$pos < count($list)">
<xsl:call-template name="isInSubmenu">
<xsl:with-param name="list" select="$list"/>
<xsl:with-param name="pos" select="$pos + 1"/>
<xsl:with-param name="curpagename" select="$curpagename"/>
</xsl:call-template>
</xsl:when>
<xsl:otherwise>
0
</xsl:otherwise>
</xsl:choose>
</xsl:when>
<xsl:otherwise>
1
</xsl:otherwise>
</xsl:choose>
</xsl:template>
</xsl:stylesheet>