Trouble with sum() and position()

bbenick · October 23rd, 2009, 03:59 PM

I'm trying to sum up values by groups of 5 using a recursive call template, but something strange is happening.

Here is my input document:

Code:

<LOB full="Happyguard">
			<day date="10/05/09" lob="Happyguard" totalFailed="13"></day>
			<day date="10/06/09" lob="Happyguard" totalFailed="11"></day>
			<day date="10/07/09" lob="Happyguard" totalFailed="8"></day>
			<day date="10/08/09" lob="Happyguard" totalFailed="33"></day>
			<day date="10/09/09" lob="Happyguard" totalFailed="45"></day>
			<day date="10/12/09" lob="Happyguard" totalFailed="9"></day>
			<day date="10/13/09" lob="Happyguard" totalFailed="1"></day>
			<day date="10/14/09" lob="Happyguard" totalFailed="78"></day>
			<day date="10/15/09" lob="Happyguard" totalFailed="42"></day>
			<day date="10/16/09" lob="Happyguard" totalFailed="72"></day>
			<day date="10/19/09" lob="Happyguard" totalFailed="11"></day>
			<day date="10/20/09" lob="Happyguard" totalFailed="38"></day>
			<day date="10/21/09" lob="Happyguard" totalFailed="42"></day>
			<day date="10/22/09" lob="Happyguard" totalFailed="0"></day>
		</LOB>

This is the transformation:

Code:

<xsl:template match="/">
		<xsl:for-each select="LOB">
			<xsl:call-template name="aggregateWeek"/>
		</xsl:for-each>
	</xsl:template>

	<xsl:template name="aggregateWeek">
		<xsl:param name="startPosition" select="1"/>
		<xsl:variable name="countDays" select="count(day)"/>
		<xsl:variable name="endPosition">
			<xsl:choose>
				<xsl:when test="$countDays gt ($startPosition + 4)">
					<xsl:value-of select="($startPosition + 4)"/>
				</xsl:when>
				<xsl:otherwise>
					<xsl:value-of select="$countDays"/>
				</xsl:otherwise>
			</xsl:choose>
		</xsl:variable>
		<xsl:element name="week">
			<xsl:attribute name="lob" select="@full"/>
			<xsl:attribute name="startDate" select="day[position()=$startPosition]/@date"/>
			<xsl:attribute name="endDate" select="day[position()=$endPosition]/@date"/>
			<xsl:attribute name="totalFailed" select="sum(day[position() ge $startPosition][position() le xs:integer($endPosition)]/@totalFailed)"/>
		</xsl:element>
		<xsl:if test="xs:integer($endPosition) lt $countDays">
			<xsl:call-template name="aggregateWeek">
				<xsl:with-param name="startPosition" select="($startPosition + 5)"/>
			</xsl:call-template>
		</xsl:if>
	</xsl:template>
</xsl:stylesheet>

Here is the output I'm getting:

Code:

<week startDate="10/05/09" lob="Happyguard" totalFailed="110" endDate="10/09/09"></week>
		<week startDate="10/12/09" lob="Happyguard" totalFailed="293" endDate="10/16/09"></week>
		<week startDate="10/19/09" lob="Happyguard" totalFailed="91" endDate="10/22/09"></week>

Notice week 2 is not correct. Nodes 1-5 sum correctly. Nodes 11-14 sum correctly. But with week 2, it's almost as if it's summing from nodes 6-14. Can anyone shed light onto what is happening here?

Thanks

mhkay · October 23rd, 2009, 04:09 PM

Try replacing

Code:

day[position() ge $startPosition][position() le xs:integer($endPosition)]

by

Code:

day[position() ge $startPosition and position() le xs:integer($endPosition)]

In the second predicate, position() refers to the position of a node in the sequence after applying the first predicate, not the position in the original sequence.

Alternatively, write

Code:

day[position() = ($startPosition to $endPosition)]

And I would suggest adding

Code:

as="xs:integer"

to the relevant xsl:variable and xsl:param declarations.