Question

I have an xml document that looks something like this:

<units>
    <unit>
       <year></year>
       <month></month>
       <qty></qty>
    </unit>
</units>

I want to create a crosstab view of this data in html with each row represented by a year, each column represented by a month, and each value containing the sum of the qty’s for the specific year/month. Something a little like this:

      Jan  Feb   Mar   Apr.... etc
2010  345    0    12     0
2011    1   23   344     0
2012   99    1    23     0.... etc

My primary question is this: is crosstab even possible with xslt?

My follow-up question would be can you point an xslt newbie, such as myself, in the right direction to get started trying to make this work?

SAMPLE DATA:

<units>
    <unit>
        <year>2010</year>
        <month>9</month>
        <qty>13320</qty>
    </unit>
    <unit>
        <year>2010</year>
        <month>9</month>
        <qty>2445</qty>
    </unit>
    <unit>
        <year>2010</year>
        <month>10</month>
        <qty>8949</qty>
    </unit>
    <unit>
        <year>2010</year>
        <month>10</month>
        <qty>13650</qty>
    </unit>
    <unit>
        <year>2010</year>
        <month>11</month>
        <qty>4091</qty>
    </unit>
    <unit>
        <year>2010</year>
        <month>11</month>
        <qty>6600</qty>
    </unit>
    <unit>
        <year>2010</year>
        <month>12</month>
        <qty>686</qty>
    </unit>
    <unit>
        <year>2010</year>
        <month>12</month>
        <qty>678</qty>
    </unit>

    <unit>
        <year>2011</year>
        <month>1</month>
        <qty>1234</qty>
    </unit>
    <unit>
        <year>2011</year>
        <month>1</month>
        <qty>12345</qty>
    </unit>
    <unit>
         <year>2011</year>
        <month>2</month>
        <qty>4500</qty>
    </unit>
    <unit>
        <year>2011</year>
        <month>2</month>
        <qty>999</qty>
    </unit>
    <unit>
        <year>2011</year>
        <month>3</month>
        <qty>166</qty>
    </unit>
    <unit>
         <year>2011</year>
        <month>3</month>
        <qty>456666</qty>
    </unit>
    <unit>
        <year>2011</year>
        <month>4</month>
        <qty>41113</qty>
    </unit>
    <unit>
        <year>2011</year>
        <month>4</month>
        <qty>1150</qty>
    </unit>
    <unit>
        <year>2011</year>
        <month>5</month>
        <qty>4150</qty>
    </unit>
    <unit>
        <year>2011</year>
        <month>5</month>
        <qty>491</qty>
    </unit>
    <unit>
        <year>2011</year>
        <month>6</month>
        <qty>11250</qty>
    </unit>
    <unit>
        <year>2011</year>
        <month>6</month>
        <qty>3400</qty>
    </unit>
    <unit>
         <year>2011</year>
        <month>7</month>
        <qty>485</qty>
    </unit>
    <unit>
        <year>2011</year>
        <month>7</month>
        <qty>90</qty>
    </unit>
    <unit>
        <year>2011</year>
        <month>8</month>
        <qty>1606</qty>
    </unit>
    <unit>
         <year>2011</year>
        <month>8</month>
        <qty>202000</qty>
    </unit>
    <unit>
        <year>2011</year>
        <month>9</month>
        <qty>45333</qty>
    </unit>
    <unit>
        <year>2011</year>
        <month>9</month>
        <qty>13650</qty>
    </unit>
    <unit>
        <year>2011</year>
        <month>10</month>
        <qty>4050</qty>
    </unit>
    <unit>
        <year>2011</year>
        <month>10</month>
        <qty>431</qty>
    </unit>
    <unit>
        <year>2011</year>
        <month>11</month>
        <qty>45713</qty>
    </unit>
    <unit>
        <year>2011</year>
        <month>11</month>
        <qty>13690</qty>
    </unit>
    <unit>
        <year>2011</year>
        <month>12</month>
        <qty>4050</qty>
    </unit>
    <unit>
        <year>2011</year>
        <month>12</month>
        <qty>431</qty>
    </unit>

    <unit>
        <year>2012</year>
        <month>1</month>
        <qty>2500</qty>
    </unit>
    <unit>
        <year>2012</year>
        <month>1</month>
        <qty>34100</qty>
    </unit>
    <unit>
        <year>2012</year>
        <month>2</month>
        <qty>400</qty>
    </unit>
    <unit>
        <year>2012</year>
        <month>2</month>
        <qty>99</qty>
    </unit>
    <unit>
        <year>2012</year>
        <month>3</month>
        <qty>1606</qty>
    </unit>
    <unit>
        <year>2012</year>
        <month>3</month>
        <qty>202000</qty>
    </unit>
    <unit>
        <year>2012</year>
        <month>4</month>
        <qty>53773</qty>
    </unit>
    <unit>
        <year>2012</year>
        <month>4</month>
        <qty>13650</qty>
    </unit>
    <unit>
        <year>2012</year>
        <month>5</month>
        <qty>4150</qty>
    </unit>
    <unit>
        <year>2012</year>
        <month>5</month>
        <qty>4231</qty>
    </unit>
    <unit>
        <year>2012</year>
        <month>6</month>
        <qty>278</qty>
    </unit>
    <unit>
        <year>2012</year>
        <month>6</month>
        <qty>6100</qty>
    </unit>
    <unit>
        <year>2012</year>
        <month>7</month>
        <qty>406</qty>
    </unit>
    <unit>
        <year>2012</year>
        <month>7</month>
        <qty>95</qty>
    </unit>

</units>

Answer 1

Here is an XSLT 1.0 solution (there might be some work needed to make the numbers align properly):

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
 <xsl:output omit-xml-declaration="yes" indent="yes"/>
 <xsl:key name="kUnitByY" match="unit" use="year"/>
 <xsl:key name="kUnitByYM" match="unit" use="concat(year,'|',month)"/>

 <xsl:template match="/*">
<xsl:text>      Jan  Feb  Mar  Apr  May  Jun  Jul  Aug  Sep  Oct  Nov  Dec</xsl:text>
  <xsl:apply-templates select=
   "unit[generate-id()=generate-id(key('kUnitByY',year)[1])]">
    <xsl:sort select="year" data-type="number"/>
   </xsl:apply-templates>
 </xsl:template>

 <xsl:template match="unit">
  <xsl:value-of select="concat('&#xA;',year,'  ')"/>

  <xsl:variable name="vCur" select="."/>

  <xsl:for-each select="(//node()|//namespace::*)[not(position() >12)]">
    <xsl:value-of select=
    "sum(key('kUnitByYM', concat($vCur/year,'|',position()))/qty)"/>
    <xsl:text>    </xsl:text>
  </xsl:for-each>
 </xsl:template>
</xsl:stylesheet>

When this transformation is applied on the following XML document (none was provided !!!):

2010
2
3

2010
3
44

2010
9
44

2011
1
5

2011
3
11

2011
6
11

2011
4
15

the wanted, correct result is produced:

      Jan  Feb  Mar  Apr  May  Jun  Jul  Aug  Sep  Oct  Nov  Dec
2010  0    3    44    0    0    0    0    0    44    0    0    0    
2011  5    0    11    15    0    11    0    0    0    0    0    0