Loop through XML?

Andy-7M · May 4th, 2007, 03:30 AM

Hi there,

how do I loop through an XML document, and change/delete only <gco:CharacterString> elements?

The other part of the document should be untouched.

The problem is, I cannot display the exact copy of XML (doing XSLT XML -> XML, Xalan) and the search criteria doesn't seem to work:

Code:

    <xsl:template match="//gco:CharacterString"> 
    <xsl:value-of select="./text()"/>

Any guidelines here?

joefawcett · May 4th, 2007, 03:56 AM

You need the identity template with an extra template to match gco:CharacterString.

Code:

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:gco="gco namespace uri goes here">

  <xsl:template match="node()|@*">

    <xsl:copy>

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


  <xsl:template match="gco:CharacterString">

  </xsl:template>
</xsl:stylesheet>

--

Joe (Microsoft MVP - XML)

Andy-7M · May 4th, 2007, 06:17 AM

Joe,

the code you wrote does find some of the elements, but <gco:CharacterString>. And it returns me plain text, without any tree structure...

Andy-7M · May 4th, 2007, 06:33 AM

I re-wrote the code:

Code:

    <xsl:template match="* | @* | text()">

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

    </xsl:template>

Now I am able to make a copy of my tree and I am able to see nodes, attributes and text as an output result.

The only question -- <gco:CharacterString> removal -- is still vague for me.

joefawcett · May 4th, 2007, 08:10 AM

The change you made is somewhat irrelevant as the node() test includes the text() test. Why not show the source XML and clarify what you want to happen to the <gco:CharacterString> element. Do you want it removed, along with its children or just removed?

As to the output format I'm not sure how you are trying to view it but I have used the identity template countless times and it always returns XML.

--

Joe (Microsoft MVP - XML)

Andy-7M · May 4th, 2007, 09:20 AM

Well, say we got a chunk of code, which is more than enough, I think:

Code:

<citation>
   <CI_Citation>
      <title xsi:type="PT_FreeText_PropertyType">
         <gco:CharacterString>Dataset of the TDEM measurement campaign in Uveghuta, 2002 
         </gco:CharacterString>
      <PT_FreeText>
         textGroup # 13
      </PT_FreeText>
      </title>
   </CI_Citation>
</citation>

Currently, I am doing a transformation, using XSLT, of course. The main goal is to transform the XML document, to another XML document, removing some unnecessary tags or whatsoever. So, long story short, this is what I want to do (quite self-explanatory code):

Code:

<citation>
   <CI_Citation>
      <title xsi:type="PT_FreeText_PropertyType">
         Dataset of the TDEM measurement campaign in Uveghuta, 2002
      <PT_FreeText>
         textGroup # 13
      </PT_FreeText>
      </title>
   </CI_Citation>
</citation>

Well, at least I have moved one step further by being able to transform the exact copy of the document.

Sorry if those questions look too basic. It's just that I need to do this quick transformation. And with the knowledge of XSLT for a couple of days along with reading half of the book, sometimes I found myself stuck at it.

Any input is appreciated.

Andy-7M · May 5th, 2007, 12:45 AM

OK, another step further.

The recent XSL code:

Code:

<?xml version="1.0" encoding="ISO-8859-1"?> 
<xsl:stylesheet version="1.0" 

    xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:default="http://www.isotc211.org/2005/gmd"
    xmlns:gco="http://www.isotc211.org/2005/gco" 
    xmlns:gml="http://www.opengis.net/gml" 
    xmlns:xlink="http://www.w3.org/1999/xlink" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

<xsl:output method="xml"/>


    <xsl:variable name="lang">#xpointer(//*[@id='hu'])</xsl:variable>
    <xsl:variable name="lang_hu" select="//identificationInfo//title[@locale]"/>

    <xsl:template match="* | @* | text()">

        <xsl:copy>
            <xsl:apply-templates select="* | @* | text()"/>
            <xsl:apply-templates select="gco:CharacterString"/>
        </xsl:copy>

        <xsl:if test="$lang = $lang_hu">
            <xsl:value-of select="//@locale/text()"/>
        </xsl:if>

    </xsl:template>

        <xsl:template match="gco:CharacterString">

        </xsl:template> 


</xsl:stylesheet>

Don't mind the declaration and usage of variables. Still got to work on it.

The thing is, now I can display all the document along with _deleted_ <gco:CharacterString>. What I want to do, is preserve the text value of <gco:CharacterString> and move it one branch higher.

I know I have to improve the bolded template probably this way:
(1) copy the text value of <gco:CharacterString>
(2) delete the node
(3) insert the text value one step higher, probably the parent branch (using ".." I guess?)

Or am I misunderstanding the algorithm?

Andy

joefawcett · May 5th, 2007, 02:55 AM

You can just use the template I suggested originally. Just change the override to:

Code:

<xsl:template match="gco:CharacterString">
  <xsl:appply-templates/>
</xsl:template>

--

Joe (Microsoft MVP - XML)

Andy-7M · May 5th, 2007, 06:03 AM

Nice.

Thanks Joe