How to know whether the father element has child elements or not

JohnKiller · September 18th, 2012, 01:43 AM

There are several loop father nodes which contain several child elements, like below:

Quote:

<?xml version="1.0" encoding="utf-8" ?>
<ns0:PO xmlns:ns0="http://HelloWorld.POSchema">
<PO_Number>16</PO_Number>
<Total>PO_Number1234</Total>
<PO_Number2>6</PO_Number2>
<PO_Number3>5</PO_Number3>
<PORoot>
<PORoot1>PORoot1</PORoot1>
<PORoot2>PORoot2</PORoot2>
<POChild>
<POChild1>POChild1</POChild1>
<POChild2>POChild2</POChild2>
</POChild>
<PORoot1>PORoot3</PORoot1>
<PORoot2>PORoot4</PORoot2>
<POChild>
<POChild1>POChild3</POChild1>
<POChild2></POChild2>
</POChild>
<PORoot1>PORoot5</PORoot1>
<PORoot2>PORoot6</PORoot2>
<POChild>
<POChild1></POChild1>
<POChild2></POChild2>
</POChild>
<PORoot1></PORoot1>
<PORoot2></PORoot2>
<POChild>
<POChild1></POChild1>
<POChild2></POChild2>
</POChild>
</PORoot>
</ns0:PO>

What I want to do is that I want to remove all the empty POChild nodes, if the two child POChild1/2 nodes are empty, remove the father node POChild as well.

I have no idea how to achive this.

The output xml should be like below, but probably a little different:

Code:

<?xml version="1.0" encoding="utf-8" ?>
<PO>
  <PO_Number>16</PO_Number>
  <Total>PO_Number1234</Total>
  <PO_Number2>6</PO_Number2>
  <PO_Number3>5</PO_Number3>
  <PORoot>
    <PORoot1>PORoot1</PORoot1>
    <PORoot2>PORoot2</PORoot2>
    <POChild>
      <POChild1>POChild1</POChild1>
      <POChild2>POChild2</POChild2>
    </POChild>
    <PORoot1>PORoot3</PORoot1>
    <PORoot2>PORoot4</PORoot2>
    <POChild>
      <POChild1>POChild3</POChild1>
    </POChild>
    <PORoot1>PORoot5</PORoot1>
    <PORoot2>PORoot6</PORoot2>
  </PORoot>
</PO>

ATTENTION: The first node is ns0:PO with xmlns.

Thank you so much in advance!

mhkay · September 18th, 2012, 04:45 AM

You want a transformation that defines an identity rule to copy elements by default:

Code:

<xsl:template match="*">
  <xsl:copy><xsl:apply-templates/></xsl:copy>
</xsl:template>

and then rules to avoid copying POChild, POChild1, and POChild2 elements if they have no text content:

Code:

<xsl:template match="n:POChild[not(normalize-space())]"/>
<xsl:template match="n:POChild1[not(normalize-space())]"/>
<xsl:template match="n:POChild2[not(normalize-space())]"/>

The namespace prefix "n" should be bound to the right namespace by adding

xmlns:n="http://HelloWorld.POSchema"

to your xsl:stylesheet element. Of course you can use a different namespace prefix if you prefer.

JohnKiller · September 18th, 2012, 06:13 AM

Hello Michael,
Thank you for your reply.
Is there any way to put them in one template, like we deal with the node without namespace? <xsl:template match="PO">

mhkay · September 18th, 2012, 06:24 AM

Why on earth would you want to put code in a single template when it can be broken up cleanly into several independent templates?

JohnKiller · September 18th, 2012, 06:30 AM

Since I really do not know how to assemble all the templates together, and the relationships among them. The material which I found online make me confusing. And when I tested the templates, it cannot work right.

mhkay · September 18th, 2012, 04:24 PM

>The material which I found online make me confusing

Did you know that Wrox publishes books on XML, and that this forum is primarily intended for readers of those books?

If you're not used to learning from books, I can really recommend it. Unlike most online resources, books are carefully designed, written, edited, and proofread, and Wrox has a high reputation for the quality of the reviewers who ensure that the material is consistent, correct, and well-presented.

JohnKiller · September 18th, 2012, 07:40 PM

Sound great! Yes, I have several Wrox books, but no one is related to XML and XSLT.

I searched Wrox Bookstore/E-Books, there are a lot of books related to XML and XSLT. Would you give me recommendation which book is better?

Thank you!

shil · October 18th, 2012, 09:50 AM

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:ns0="http://HelloWorld.POSchema">
<xsl:output method="xml"/>
<xsl:template match="/">
<xsl:apply-templates select="ns0:PO"/>
</xsl:template>
<xsl:template match="ns0:PO">
<xsl:element name="PO">
<xsl:copy-of select="child::* except PORoot" copy-namespaces="no"/>
<xsl:apply-templates select="PORoot"/>
</xsl:element>
</xsl:template>
<xsl:template match="PORoot">
<xsl:element name="PORoot">
<xsl:apply-templates/>
</xsl:element>
</xsl:template>
<xsl:template match="POChild">
<xsl:if test="child::* and child::*[text()!=' ']">
<xsl:element name="POChild">
<xsl:for-each select="child::*">
<xsl:if test="text()!= ' '">
<xsl:copy-of select="." copy-namespaces="no"/>
</xsl:if>
</xsl:for-each>
</xsl:element>
</xsl:if>
</xsl:template>
<xsl:template match="PORoot1">
<xsl:if test="text()!=' '">
<xsl:element name="PORoot1">
<xsl:value-of select="."/>
</xsl:element>
</xsl:if>
</xsl:template>

<xsl:template match="PORoot2">
<xsl:if test="text()!=' '">
<xsl:element name="PORoot2">
<xsl:value-of select="."/>
</xsl:element>
</xsl:if>
</xsl:template>
</xsl:stylesheet>