Question

This is my xml Document.

<w:document xmlns:w="w">
 <w:body>
   <w:p>
        <w:r>
           <w:t>
               Para1
            </w:t>
        </w:r>
     </w:p>
   <w:p>
        <w:r>
           <w:t>
               Para2
            </w:t>
        </w:r>
     </w:p>
   <w:p>
        <w:r>
           <w:t>
               Para3
            </w:t>
        </w:r>
     </w:p>
   <w:p>
        <w:r>
           <w:t>
               Para4
            </w:t>
        </w:r>
     </w:p>
   <w:p>
        <w:r>
           <w:t>
               Para5
            </w:t>
        </w:r>
     </w:p>

   <w:tbl>
         <w:tr>
            <w:tc>
               <w:p>
                  <w:r>
                    <w:t>
                         Para6
                    </w:t>
                   </w:r>
                </w:p>
              </w:tc>
            <w:tc>
               <w:p>
                  <w:r>
                    <w:t>
                         Para7 
                    </w:t>
                   </w:r>
                </w:p>
              </w:tc>
           </w:tr>
        </w:tbl>
     <w:p>
        <w:r>
           <w:t>
               Para8
            </w:t>
        </w:r>
     </w:p>
  <w:tbl>
         <w:tr>
            <w:tc>
               <w:p>
                  <w:r>
                    <w:t>
                         Para9
                    </w:t>
                   </w:r>
                </w:p>
              </w:tc>
            <w:tc>
               <w:p>
                  <w:r>
                    <w:t>
                         Para10
                    </w:t>
                   </w:r>
                </w:p>
              </w:tc>
           </w:tr>
        </w:tbl>
    <w:p>
        <w:r>
           <w:t>
               Para11
            </w:t>
        </w:r>
     </w:p>
</w:body>
</w:document>

Now, I want to increment my global variable whenever <w:tbl><w:tr> encounters.for my above xml file,it has two <w:tr> nodes inside <w:tbl>.

So, for example :  
                1. if my current node is Para8 then it's count will be 1.
                2. if my current node is para11 then it's count will be 2.
   

How i do it?

Answer 1

XSLT is a functional language and in any functional language the value of a variable, one set, cannot be updated. One needs a “paradigm shift” — to start thinking in a functional way — in order to understand that the “capability” to update variables isn’t necessary at all. For any imperative algorithm (that uses variable update) there is a corresponding functional algorithm (that doesn’t require update of any variable).

There are a number of advantages using a functional programming style over an imperative one — the main being that a functional program is much better to read, understand, maintain and even prove correct. Due to variables being immutable, the optimizer of a compiler can perform much more aggressive optimizations and this results in more efficient, highly optimized compiled programs.

In this particular case, it isn’t necessary to update a variable in order to get the required count:

<xsl:stylesheet version="1.0"
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
 xmlns:w="w">
 <xsl:output method="text"/>
 <xsl:strip-space elements="*"/>

 <xsl:template match="node()|@*">
     <xsl:for-each select=
      "//w:t
         [contains(., 'Para8')
         or
          contains(., 'Para11')
         ]
     ">
       <xsl:number level="any" count="w:tbl/w:tr"/>
       <xsl:text>&#xA;</xsl:text>
     </xsl:for-each>
 </xsl:template>
</xsl:stylesheet>

When this transformation is applied on the provided XML document:

 <w:document xmlns:w="w">
    <w:body>
        <w:p>
            <w:r>
                <w:t>                Para1             </w:t>
            </w:r>
        </w:p>
        <w:p>
            <w:r>
                <w:t>                Para2             </w:t>
            </w:r>
        </w:p>
        <w:p>
            <w:r>
                <w:t>                Para3             </w:t>
            </w:r>
        </w:p>
        <w:p>
            <w:r>
                <w:t>                Para4             </w:t>
            </w:r>
        </w:p>
        <w:p>
            <w:r>
                <w:t>                Para5             </w:t>
            </w:r>
        </w:p>
        <w:tbl>
            <w:tr>
                <w:tc>
                    <w:p>
                        <w:r>
                            <w:t>                          Para6                     </w:t>
                        </w:r>
                    </w:p>
                </w:tc>
                <w:tc>
                    <w:p>
                        <w:r>
                            <w:t>                          Para7                      </w:t>
                        </w:r>
                    </w:p>
                </w:tc>
            </w:tr>
        </w:tbl>
        <w:p>
            <w:r>
                <w:t>                Para8             </w:t>
            </w:r>
        </w:p>
        <w:tbl>
            <w:tr>
                <w:tc>
                    <w:p>
                        <w:r>
                            <w:t>                          Para9                     </w:t>
                        </w:r>
                    </w:p>
                </w:tc>
                <w:tc>
                    <w:p>
                        <w:r>
                            <w:t>                          Para10                     </w:t>
                        </w:r>
                    </w:p>
                </w:tc>
            </w:tr>
        </w:tbl>
        <w:p>
            <w:r>
                <w:t>                Para11             </w:t>
            </w:r>
        </w:p>
    </w:body>
</w:document>

the wanted, correct result is produced:

1
2

In case this value should be contained in a variable — to be used later somewhere in its scope, one will simply define the variable as:

 <xsl:variable name="vMyCount">
   <xsl:number level="any" count="w:tbl/w:tr"/>
 </xsl:variable>

And you can use this variable as in the transformation below:

<xsl:stylesheet version="1.0"
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
 xmlns:w="w">
 <xsl:output method="text"/>
 <xsl:strip-space elements="*"/>

 <xsl:template match="node()|@*">
     <xsl:for-each select=
      "//w:t
         [contains(., 'Para5')
         or
          contains(., 'Para8')
         or
          contains(., 'Para11')
         ]
     ">
     <xsl:variable name="vMyCount">
       <xsl:number level="any" count="w:tbl/w:tr"/>
     </xsl:variable>
     <xsl:value-of select=
      "concat($vMyCount,
              substring('0', 1 + boolean(string($vMyCount)))
              )"/>
       <xsl:text>&#xA;</xsl:text>
     </xsl:for-each>
 </xsl:template>
</xsl:stylesheet>

producing the same correct result:

0
1
2