Question

Suppose I have a xml

<Root>
<TB>
..
</TB>
<TB>
..

</TB>
<TB>
..
<DIACT>2</DIACT>
</TB>
<TB>
...
<DIACT>3</DIACT>
</TB>
<TB>
----
<DIACT>4</DIACT>
---
</TB>
</Root>

I want to get the position of first TB node where DIACT is not null or DIACT node exist, using xslt mapping. Like in this case postion should give me output as 3. As 3rd TB node is the first one with DIACT not null.

Answer 1

Use:

count(/*/TB[DIACT][1]/preceding-sibling::TB) +1

As you need this for futher procesing, set a variable that has the above value:

<xsl:variable name="vPos" 
              select="count(/*/TB[DIACT][1]/preceding-sibling::TB) +1"/>

Alternatively, one can use xsl:number :

  <xsl:variable name="vPos2">
    <xsl:number count="TB"/>
  </xsl:variable>

Here is a simple demo of the two techniques:

 <xsl:template match="/">
    <xsl:variable name="vPos"
        select="count(/*/TB[DIACT][1]/preceding-sibling::TB) +1"/>

    <xsl:value-of select="$vPos"/>
=========== 
    <xsl:for-each select="/*/TB[DIACT][1]">
      <xsl:variable name="vPos2">
        <xsl:number count="TB"/>
      </xsl:variable>
      <xsl:value-of select="$vPos2"/>
    </xsl:for-each>
 </xsl:template>
</xsl:stylesheet>

when this transformation is applied on the provided XML document:

<Root>
    <TB> .. </TB>
    <TB> ..  </TB>
    <TB> .. 
        <DIACT>2</DIACT>
    </TB>
    <TB> ... 
        <DIACT>3</DIACT>
    </TB>
    <TB> ---- 
        <DIACT>4</DIACT> --- 
    </TB>
</Root>

two correct results are produced:

3
=========== 
3