Question

I am trying to create a gap between rows everytime the value of ‘column3’ changes. At the moment the gap is set to appear every 2 rows which is not what i need.
For example the value of ‘column3’ in the first 10 rows is 1,1,3,3,3,3,5,5,5,5
And i want a gap between the last ‘1’ and first ‘3’ etc.

 <xsl:for-each select="Market">
        <tr>
          <td>
            <xsl:value-of select="Column1"/>
          </td>
          <td>
            <xsl:value-of select="Column2"/>
          </td>
          <td>
            <xsl:value-of select="Column3"/>
          </td>
        </tr>
          <xsl:if test="(position() mod 2 = 0)">
          <tr>
            <td colspan="5" height="25px" />
          </tr>
        </xsl:if>

Answer 1

You could make use of the following-sibling axis in XPath to do this.

<xsl:if test="Column3 != following-sibling::Market[1]/Column3">

i.e. Does the very next Market element have a Column3 element with a different value.

For example, given the following XML

<Markets>
    <Market>
        <Column1>A</Column1>
        <Column3>1</Column3>
    </Market>
    <Market>
        <Column1>A</Column1>
        <Column3>1</Column3>
    </Market>
    <Market>
        <Column1>A</Column1>
        <Column3>3</Column3>
    </Market>
    <Market>
        <Column1>A</Column1>
        <Column3>3</Column3>
    </Market>
    <Market>
        <Column1>A</Column1>
        <Column3>3</Column3>
    </Market>
    <Market>
        <Column1>A</Column1>
        <Column3>3</Column3>
    </Market>
    <Market>
        <Column1>B</Column1>
        <Column3>4</Column3>
    </Market>
    <Market>
        <Column1>B</Column1>
        <Column3>4</Column3>
    </Market>
</Markets>

When you apply the following XSLT

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
   <xsl:output method="html" indent="yes"/>
   <xsl:template match="/Markets">
      <table>
         <xsl:apply-templates select="Market"/>
      </table>
   </xsl:template>

   <xsl:template match="Market">
      <tr>
         <td>
            <xsl:value-of select="Column1"/>
         </td>
         <td>
            <xsl:value-of select="Column3"/>
         </td>
      </tr>
      <xsl:if test="Column3 != following-sibling::Market[1]/Column3">
         <tr>
            <td colspan="2" height="25px"/>
         </tr>
      </xsl:if>
   </xsl:template>
</xsl:stylesheet>

Then the following is output

<table>
   <tr>
      <td>A</td>
      <td>1</td>
   </tr>
   <tr>
      <td>A</td>
      <td>1</td>
   </tr>
   <tr>
      <td colspan="2" height="25px"/>
   </tr>
   <tr>
      <td>A</td>
      <td>3</td>
   </tr>
   <tr>
      <td>A</td>
      <td>3</td>
   </tr>
   <tr>
      <td>A</td>
      <td>3</td>
   </tr>
   <tr>
      <td>A</td>
      <td>3</td>
   </tr>
   <tr>
      <td colspan="2" height="25px"/>
   </tr>
   <tr>
      <td>B</td>
      <td>4</td>
   </tr>
   <tr>
      <td>B</td>
      <td>4</td>
   </tr>
</table>

(Note, I missed out Column2 just for some brevity).