I want to copy a big xml as-it-is but need to change just one value in it.

For example let's say I have the below xml:

<?xml version="1.0" encoding="UTF-8"?>
<root>
    <row>
        <col1>A</col1>
        <col2>B</col2>
        <col3>C</col3>
        <col4>D</col4>
        <col5>E</col5>
        <col6>F</col6>
        <col7>G</col7>
        <col8>H</col8>
        <col9>I</col9>
        <col10>J</col10>
    </row>
    <row>
        <col1>A</col1>
        <col2>B</col2>
        <col3>C</col3>
        <col4>D</col4>
        <col5>E</col5>
        <col6>F</col6>
        <col7>G</col7>
        <col9>I</col9>
        <col10>J</col10>
    </row>
</root>

Now, I want the entire xml as it is but modify one value - col8

Expected output file:

    <?xml version="1.0" encoding="UTF-8"?>
    <root>
        <row>
            <col1>A</col1>
            <col2>B</col2>
            <col3>C</col3>
            <col4>D</col4>
            <col5>E</col5>
            <col6>F</col6>
            <col7>G</col7>
            <col8>NEW</col8>   <------ Updated data
            <col9>I</col9>
            <col10>J</col10>
        </row>
        <row>
            <col1>A</col1>
            <col2>B</col2>
            <col3>C</col3>
            <col4>D</col4>
            <col5>E</col5>
            <col6>F</col6>
            <col7>G</col7>
            <col8>ADD</col8>   <------ Added data
            <col9>I</col9>
            <col10>J</col10>
        <row>
    </root>

My xml has around 5000 lines of data in which I have to update just one value. copy-of seems to copy everything and not allowing me to update one value. Please help if this is possible.

CodePudding user response：

Try the standard approach:

XSLT 3.0

<xsl:stylesheet version="3.0" 
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="xml" version="1.0" encoding="UTF-8" indent="yes"/>

<xsl:mode on-no-match="shallow-copy"/>

<xsl:template match="col8">
    <xsl:copy>NEW</xsl:copy>
</xsl:template>

</xsl:stylesheet>

CodePudding user response：

To inject missing col8 entries, add one more template:

<xsl:template match="col7[not(../col8)]">
  <xsl:copy-of select="."/>
  <col8>ADD</col8>
</xsl:template>

This assumes that col7 always exists.

CodePudding user response：

If you need if you need to work with "col8" differently if it exists or it does not, you could do it like this :

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    version="3.0">

  <xsl:mode on-no-match="shallow-copy"/>

  <xsl:output method="xml" indent="yes" html-version="5"/>

  <!-- Case where col8 exists -->
  <xsl:template match="col8">
    <xsl:copy>NEW</xsl:copy>
  </xsl:template>
  
  <!-- Case where col8 needs to be added -->
  <xsl:template match="row[not(col8)]">
    <xsl:copy>
      <xsl:apply-templates/>
      <col8>ADD</col8>
    </xsl:copy>
  </xsl:template>
  
</xsl:stylesheet>

Else this would take care of both cases :

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    version="3.0">

  <xsl:mode on-no-match="shallow-copy"/>

  <xsl:output method="xml" indent="yes" html-version="5"/>
  
  <xsl:template match="row">
    <xsl:copy>
      <xsl:apply-templates select="*[not(self::col8)]"/>
      <col8>NEW DATA</col8>
    </xsl:copy>
  </xsl:template>
  
</xsl:stylesheet>

And if you need the columns to be in numerical order :

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    version="3.0">

  <xsl:mode on-no-match="shallow-copy"/>

  <xsl:output method="xml" indent="yes" html-version="5"/>
  
  <xsl:template match="row">
    <xsl:variable name="temp">
        <xsl:apply-templates select="*[not(self::col8)]"/>
        <col8>NEW DATA</col8>
    </xsl:variable>
    <xsl:copy>
      <xsl:for-each select="$temp/*">
        <xsl:sort select="replace(name(.),'col','')" data-type="number"/>
        <xsl:sequence select="."/>
      </xsl:for-each>
    </xsl:copy>
    
  </xsl:template>
  
</xsl:stylesheet>