Recursion problem

dani1 · November 26th, 2008, 09:36 AM

Hi!

I have to do this transformation:

Source:

Code:

<root>

    <Invoice>
        <Invoice_Num>0</Invoice_Num>
        <InvoiceData1>aa</InvoiceData1>
        <InvoiceData2>bb</InvoiceData2>
    </Invoice>

    <Delivery>
        <Invoice_Num></Invoice_Num>
        <Delivery_Num>1</Delivery_Num>
        <DelData1>aa</DelData1>
        <DelData2>dd</DelData2>
    </Delivery>
    <Line>
        <Delivery_Num></Delivery_Num>
        <LineData1>1234</LineData1>
        <LineData2>4321</LineData2>
    </Line>
 
</root>

Target:

Code:

<root>

    <Invoice>
        <Invoice_Num>0</Invoice_Num>
        <InvoiceData1>11</InvoiceData1>
        <InvoiceData2>22</InvoiceData2>
    </Invoice>

    <Delivery>
        <Invoice_Num>0</Invoice_Num>
        <Delivery_Num>1</Delivery_Num>
        <DelData1>aa</DelData1>
        <DelData2>dd</DelData2>
    </Delivery>
    <Line>
        <Delivery_Num>1</Delivery_Num>
        <LineData1>1234</LineData1>
        <LineData2>4321</LineData2>
    </Line>
 
</root>

As you can see each "Delivery" must get the number of previous "Invoice", and each "Line" the number of previous "Delivery".
Each of nodes occures from 0-n times (except "Invoice", it's always occurs at least one time).
As I need to use XSLT 1.0(I' am building the mapping for SAP XI) the only way to do this kind of transformation is using the recursion, am I right?
Actually I can't understand the logic how the recursive function must work in this case, what elements I must pass (Invoice? Delivery? Line?)
My be I need three different recursive functions for each type of node? Any help would be greatly welcomed!

Martin Honnen · November 26th, 2008, 09:47 AM

I don't see why you need recursion. Accessing the preceding-sibling of the parent should suffice:

Code:

<xsl:stylesheet
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  version="1.0">


  <xsl:template match="@* | node()">
    <xsl:copy>
      <xsl:apply-templates select="@* | node()"/>
    </xsl:copy>
  </xsl:template>

  <xsl:template match="Delivery/Invoice_Num">
    <xsl:copy>
      <xsl:value-of select="../preceding-sibling::Invoice[1]/Invoice_Num"/>
    </xsl:copy>
  </xsl:template>

  <xsl:template match="Line/Delivery_Num">
    <xsl:copy>
      <xsl:value-of select="../preceding-sibling::Delivery[1]/Delivery_Num"/>
    </xsl:copy>
  </xsl:template>

</xsl:stylesheet>

--
Martin Honnen
Microsoft MVP - XML

samjudson · November 26th, 2008, 09:49 AM

For the Deliveryelement:

<xsl:template match="Delivery">
<Delivery>
<Invoice_Num><xsl:value-of select="preceding-sibling::Invoice[1]/Invoice_Num"/></Invoice_Num>
<xsl:apply-templates/>
</Delivery>
</xsl:template>
<xsl:template match="Delivery/Invoice_num" />

Repeat for Line and add an Identity transform to complete the stylesheet.

/- Sam Judson : Wrox Technical Editor -/

dani1 · November 26th, 2008, 09:59 AM

Thank you Martin, you are right. It works without recursion. Well I learned something new.
Thank's again!

dani1 · November 26th, 2008, 10:00 AM

Quote:

quote:Originally posted by samjudson
For the Deliveryelement:

<xsl:template match="Delivery">
<Delivery>
<Invoice_Num><xsl:value-of select="preceding-sibling::Invoice[1]/Invoice_Num"/></Invoice_Num>
<xsl:apply-templates/>
</Delivery>
</xsl:template>
<xsl:template match="Delivery/Invoice_num" />

Repeat for Line and add an Identity transform to complete the stylesheet.

/- Sam Judson : Wrox Technical Editor -/

Thank you Sam!

samjudson · November 26th, 2008, 10:05 AM

Yeah, Martin's solution is better.

/- Sam Judson : Wrox Technical Editor -/