How can we achieve Conditional increment in XSLT

问题:

Input:

<Order>
  <HeaderValue1>ORDER1</HeaderValue1>
  <OrderLineItems>
    <Item>`A`</Item>
  </OrderLineitems>
  <OrderLineItems>
    <Item>A</Item>
  </OrderLineItems>
  <OrderLineItems>
    <Item>`A`</Item>`
  </OrderLineItems>
  <OrderLineItems>`
    <Item>B</Item>`
  </OrderLineItems>
</Order>
<Order>
  <HeaderValue1>`ORDER2`</HeaderValue1>
  <OrderLineItems>
    <Item>B`</Item>
  </OrderLineItems>
</Order>

for each order there is a number of orderLineItems are present.For each order and items we need to assign a increment value.if the previous item value is equal to current item value.there is no need to increment just pass the value.otherwise increment value is assign to item element. I need the output is like below.

<Order>
  <HeaderValue1>1`</HeaderValue1>
  <OrderLineItems>`
    <Item>2`</Item>
  </OrderLineItems>
  <OrderLineItems>
    <Item>A`</Item>
  </OrderLineItems>
  <OrderLineItems>
    <Item>A`</Item>
  </OrderLineItems>
  <OrderLineItems>
    <Item>3`</Item>
  </OrderLineItems>
</Order>
<Order>
  <HeaderValue1>4</HeaderValue1>
  <OrderLineItems>
    <Item>5</Item>
  </OrderLineItems>
</Order>

回答1:

This transformation:

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
 <xsl:output omit-xml-declaration="yes" indent="yes"/>
 <xsl:strip-space elements="*"/>

 <xsl:template match="node()|@*">
  <xsl:param name="pNum" select="0"/>
  <xsl:copy>
   <xsl:apply-templates select="node()[1]|@*">
     <xsl:with-param name="pNum" select="$pNum"/>
   </xsl:apply-templates>
  </xsl:copy>
  <xsl:apply-templates select="following-sibling::node()[1]">
   <xsl:with-param name="pNum" select="$pNum"/>
  </xsl:apply-templates>
 </xsl:template>

 <xsl:template match="HeaderValue1">
  <xsl:param name="pNum" select="0"/>

        <HeaderValue1><xsl:value-of select="$pNum+1"/></HeaderValue1>

      <xsl:apply-templates select="following-sibling::node()[1]">
       <xsl:with-param name="pNum" select="$pNum+1"/>
    </xsl:apply-templates>
 </xsl:template>

 <xsl:template match="OrderLineItems[not(. = preceding-sibling::*[1])]">
  <xsl:param name="pNum" select="0"/>

        <OrderLineItems>
       <xsl:apply-templates select="node()[1]|@*">
         <xsl:with-param name="pNum" select="$pNum+1"/>
       </xsl:apply-templates>
        </OrderLineItems>
      <xsl:apply-templates select="following-sibling::node()[1]">
       <xsl:with-param name="pNum" select="$pNum+1"/>
      </xsl:apply-templates>
 </xsl:template>

 <xsl:template match="Item[not(. = ../preceding-sibling::*[1])]">
  <xsl:param name="pNum" select="0"/>

  <Item><xsl:value-of select="$pNum"/></Item>
 </xsl:template>

 <xsl:template match="Order">
  <xsl:param name="pNum" select="0"/>

  <Order>
   <xsl:apply-templates select="node()[1]|@*">
     <xsl:with-param name="pNum" select="$pNum"/>
   </xsl:apply-templates>
     <xsl:apply-templates select="following-sibling::node()[1]">
       <xsl:with-param name="pNum" select=
       "$pNum +1 + count(OrderLineItems[not(. = preceding-sibling::*[1])])"/>
   </xsl:apply-templates>
  </Order>

 </xsl:template>
</xsl:stylesheet>

when applied on the provided XML document (corrected to be well-formed):

<t>
    <Order>
        <HeaderValue1>ORDER1</HeaderValue1>
        <OrderLineItems>
            <Item>A</Item>
        </OrderLineItems>
        <OrderLineItems>
            <Item>A</Item>
        </OrderLineItems>
        <OrderLineItems>
            <Item>A</Item>
        </OrderLineItems>
        <OrderLineItems>
            <Item>B</Item>
        </OrderLineItems>
    </Order>
    <Order>
        <HeaderValue1>ORDER2</HeaderValue1>
        <OrderLineItems>
            <Item>B</Item>
        </OrderLineItems>
    </Order>
</t>

produces the wanted, correct result:

<t>
   <Order>
      <HeaderValue1>1</HeaderValue1>
      <OrderLineItems>
         <Item>2</Item>
      </OrderLineItems>
      <OrderLineItems>
         <Item>A</Item>
      </OrderLineItems>
      <OrderLineItems>
         <Item>A</Item>
      </OrderLineItems>
      <OrderLineItems>
         <Item>3</Item>
      </OrderLineItems>
      <Order>
         <HeaderValue1>4</HeaderValue1>
         <OrderLineItems>
            <Item>5</Item>
         </OrderLineItems>
      </Order>
   </Order>
</t>