xslt: create a schedule - xslt

Question

can someone tell me, how can I create a list of dates using xslt using a start- and end date and a parameter for the calculation period, so sth like the input
<root>
<startdate>2014/01/01</startdate>
<enddate>2015/02/20</enddate>
<period>daily</period>
</root>
gives me a list
<root>
<date>2014/01/01</date>
<date>2014/01/02</date>
...
<date>2014/02/20</date>
</root>
My node period can have values in
daily
weekly
fortnightly
monthly
So the last 3 would give me lists like
<root>
<date>2014/01/01</date>
<date>2014/01/08</date>
...
<date>2015/02/18</date>
</root>
<root>
<date>2014/01/01</date>
<date>2014/01/15</date>
...
<date>2015/02/11</date>
</root>
<root>
<date>2014/01/01</date>
<date>2014/02/01</date>
...
<date>2015/02/01</date>
</root>
with the last date smaller or equal the enddate. The date formats I would use are YYYYMMDD and DD/MM/YYYY, but I would probably be able to adapt any other date format.
Someone knows how to do this?
Thanks very much!

Answer 1

First, you must use YYYY-MM-DD format if you want your dates to be recognized as such.
Now, here's a quick-and-dirty way to achieve the requested result:
XSLT 2.0
<xsl:stylesheet version="2.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
exclude-result-prefixes="xs">
<xsl:output method="xml" version="1.0" encoding="utf-8" indent="yes"/>
<xsl:template match="/root">
<result>
<xsl:call-template name="enumerate-dates">
<xsl:with-param name="startdate" select="startdate"/>
<xsl:with-param name="enddate" select="enddate"/>
<xsl:with-param name="period" select="period"/>
</xsl:call-template>
</result>
</xsl:template>
<xsl:template name="enumerate-dates">
<xsl:param name="startdate" as="xs:date"/>
<xsl:param name="enddate" as="xs:date"/>
<xsl:param name="period"/>
<xsl:if test="$startdate le $enddate">
<date><xsl:value-of select="$startdate" /></date>
<xsl:call-template name="enumerate-dates">
<xsl:with-param name="startdate">
<xsl:choose>
<xsl:when test="$period='daily'">
<xsl:value-of select="$startdate + xs:dayTimeDuration('P1D')" />
</xsl:when>
<xsl:when test="$period='weekly'">
<xsl:value-of select="$startdate + xs:dayTimeDuration('P7D')" />
</xsl:when>
<xsl:when test="$period='fortnightly'">
<xsl:value-of select="$startdate + xs:dayTimeDuration('P14D')" />
</xsl:when>
<xsl:when test="$period='monthly'">
<xsl:value-of select="$startdate + xs:yearMonthDuration('P1M')" />
</xsl:when>
</xsl:choose>
</xsl:with-param>
<xsl:with-param name="enddate" select="$enddate"/>
<xsl:with-param name="period" select="$period"/>
</xsl:call-template>
</xsl:if>
</xsl:template>
</xsl:stylesheet>
Applied to an example input of:
<root>
<startdate>2013-12-15</startdate>
<enddate>2014-03-08</enddate>
<period>fortnightly</period>
</root>
the result is:
<?xml version="1.0" encoding="utf-8"?>
<result>
<date>2013-12-15</date>
<date>2013-12-29</date>
<date>2014-01-12</date>
<date>2014-01-26</date>
<date>2014-02-09</date>
<date>2014-02-23</date>
</result>