I want to determine whether the currentpage if of specific document type. 

What I did is as below:

<xsl:when test="$currentPage/SC_Page">
            <xsl:for-each select="$currentPage/*[@isDoc]">
              <xsl:call-template name="renderChildContent">
              </xsl:call-template>
            </xsl:for-each>
</xsl:when>

where SC_Page is document type with id= 1054 of the current page. This code doesn't work for me. I couldn't access the code within it.

Howeve I have found another workaround i.e.

<xsl:when test ="$currentPage/@nodeType = 1054">
            <xsl:for-each select="$currentPage/parent::*[@isDoc]/*[@isDoc]">
              <xsl:call-template name="renderChildContent">
              </xsl:call-template>
            </xsl:for-each>
</xsl:when>

Can anyone please explain why the first code snippet doesnt work???