REx6: [xsl] GMT to BST converter

[cknell@xxxxxxxxxx]

I have cleared up the problems I know about. Here is a tidier and shorter version of the stylesheet with the template in question. I have modified the stylesheet so I could test multiple inputs on a single run.

First my test input document:

<?xml version="1.0" encoding="UTF-8" ?>
<date-list>
 <Date>Sunday, 27 March, 2005, 01:21 GMT</Date>
 <Date>Sunday, 27 May, 2005, 01:21 GMT</Date>
 <Date>Sunday, 27 October, 2005, 01:21 GMT</Date>
 <Date>Sunday, 27 January, 2005, 01:21 GMT</Date>
 <Date>Sunday, 27 June, 2005, 23:21 GMT</Date>
</date-list>

The output document:
<?xml version="1.0" encoding="UTF-8"?>
<date-list>
  <Date>Sunday, 27 March, 2005, 2:21 BST</Date>
  <Date>Sunday, 27 May, 2005, 2:21 BST</Date>
  <Date>Sunday, 27 October, 2005, 01:21 GMT</Date>
  <Date>Sunday, 27 January, 2005, 01:21 GMT</Date>
  <Date>Monday, 28 June, 2005, 00:21 BST</Date>
</date-list>

The stylesheet:
<?xml version="1.0" encoding="UTF-8" ?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform";>
 <xsl:output method="xml" indent="yes" encoding="UTF-8" />
 <xsl:strip-space elements="*" />

 <xsl:template match="/">
   <xsl:apply-templates />
 </xsl:template>

 <xsl:template match="date-list">
   <date-list>
   <xsl:apply-templates />
 </date-list>
 </xsl:template>

 <xsl:template match="Date">
   <!-- Some convenience variables -->
     <!-- Day of the Week (e.g., Sunday) -->
     <xsl:variable name="DOW" select="substring-before(., ', ')" />

     <!-- Date and month substring (e.g., 14 January) -->
     <xsl:variable name="dm" select="substring-before(substring-after(.,', '),', ')" />

     <!-- Month name (e.g., January) -->
     <xsl:variable name="M" select="substring-after($dm,' ')" />

     <!-- Day number (e.g., 14) -->
     <xsl:variable name="D" select="substring-before($dm,' ')" />

     <!-- Hour:Minutes -->
     <xsl:variable name="h" select="substring-before(substring-after(substring-after(substring-after(.,$dm), ', '), ', '), ' GMT')" />

     <!-- Year with surrounding characters -->
     <xsl:variable name="y" select="substring-after(substring-before(., $h),$dm)" />

     <!-- Year stripped of surrounding characters -->
     <xsl:variable name="Y" select="substring-before(substring-after($y, ', '), ',')" />

   <xsl:variable name="BST-in-effect">
     <xsl:choose>
       <xsl:when test="$M = 'November' or $M = 'December' or $M = 'January' or $M = 'February'">False</xsl:when>
       <xsl:when test="$M = 'April' or $M = 'May' or $M = 'June' or $M = 'July' or $M = 'August' or $M = 'September'">True</xsl:when>
       <xsl:when test="$M = 'October'">
           <xsl:choose>
             <xsl:when test="$DOW = 'Sunday' and $D &gt; 24">False</xsl:when>
             <xsl:when test="$DOW = 'Monday' and $D &gt; 25">False</xsl:when>
             <xsl:when test="$DOW = 'Tuesday' and $D &gt; 26">False</xsl:when>
             <xsl:when test="$DOW = 'Wednesday' and $D &gt; 27">False</xsl:when>
             <xsl:when test="$DOW = 'Thursday' and $D &gt; 28">False</xsl:when>
             <xsl:when test="$DOW = 'Friday' and $D &gt; 29">False</xsl:when>
             <xsl:when test="$DOW = 'Saturday' and $D &gt; 30">False</xsl:when>
             <xsl:otherwise>True</xsl:otherwise>
           </xsl:choose>
         </xsl:when>
         <xsl:when test="$M='March'">
           <!-- Edge cases for changing to BST -->
           <xsl:choose>
             <xsl:when test="$DOW = 'Sunday' and $D &gt; 24">True</xsl:when>
             <xsl:when test="$DOW = 'Monday' and $D &gt; 25">True</xsl:when>
             <xsl:when test="$DOW = 'Tuesday' and $D &gt; 26">True</xsl:when>
             <xsl:when test="$DOW = 'Wednesday' and $D &gt; 27">True</xsl:when>
             <xsl:when test="$DOW = 'Thursday' and $D &gt; 28">True</xsl:when>
             <xsl:when test="$DOW = 'Friday' and $D &gt; 29">True</xsl:when>
             <xsl:when test="$DOW = 'Saturday' and $D &gt; 30">True</xsl:when>
             <xsl:otherwise>False</xsl:otherwise>
           </xsl:choose>
         </xsl:when>
     </xsl:choose>
   </xsl:variable>

   <xsl:choose>
     <xsl:when test="$BST-in-effect = 'False'">
       <xsl:copy-of select="." />
     </xsl:when>
     <xsl:otherwise>
     <!-- BST is in effect. Adjustments to the day of week, date, month, and hour may be necessary -->
       <xsl:variable name="D-BST">
         <!-- Check to see if the date must roll over -->
         <xsl:choose>
           <xsl:when test="number(substring-before($h, ':')) = 23">
             <xsl:choose>
               <!-- Cases where the roll-over brings the first day of the subsequent month -->
               <xsl:when test="$M = 'March' and $D = '31'">1</xsl:when>
                 <xsl:when test="$M = 'April' and $D = '30'">1</xsl:when>
                 <xsl:when test="$M = 'May' and $D = '31'">1</xsl:when>
                 <xsl:when test="$M = 'June' and $D = '30'">1</xsl:when>
                 <xsl:when test="$M = 'July' and $D = '31'">1</xsl:when>
                 <xsl:when test="$M = 'August' and $D = '31'">1</xsl:when>
                 <xsl:when test="$M = 'September' and $D = '30'">1</xsl:when>
                 <!-- Necessary only to add one to the current date -->
                 <xsl:otherwise><xsl:value-of select="number($D) + 1" /></xsl:otherwise>
             </xsl:choose>
           </xsl:when>
           <!-- No adjustment necessary -->
           <xsl:otherwise><xsl:value-of select="$D" /></xsl:otherwise>
         </xsl:choose>
       </xsl:variable>
       <xsl:variable name="DOW-BST">
         <!-- Check to see if the day of the week must roll over -->
         <xsl:choose>
           <xsl:when test="number(substring-before($h, ':')) = 23">
             <xsl:choose>
               <xsl:when test="$DOW = 'Sunday'">Monday</xsl:when>
               <xsl:when test="$DOW = 'Monday'">Tuesday</xsl:when>
               <xsl:when test="$DOW = 'Tuesday'">Wednesday</xsl:when>
               <xsl:when test="$DOW = 'Wednesday'">Thursday</xsl:when>
               <xsl:when test="$DOW = 'Thursday'">Friday</xsl:when>
               <xsl:when test="$DOW = 'Friday'">Saturday</xsl:when>
               <xsl:when test="$DOW = 'Saturday'">Sunday</xsl:when>
             </xsl:choose>
           </xsl:when>
           <xsl:otherwise><xsl:value-of select="$DOW" /></xsl:otherwise>
         </xsl:choose>
       </xsl:variable>
       <xsl:variable name="H-BST">
         <!-- Adjust the hour if necessary -->
         <xsl:choose>
           <xsl:when test="number(substring-before($h, ':')) = 23"><xsl:value-of select="concat('00:', substring-after($h, ':'))" /></xsl:when>
           <xsl:otherwise><xsl:value-of select="concat(number(substring-before($h, ':')) + 1, ':', substring-after($h, ':'))" /></xsl:otherwise>
         </xsl:choose>
       </xsl:variable>
       <xsl:variable name="M-BST">
         <!-- Adjust the month if necessary -->
         <xsl:choose>
           <xsl:when test="number(substring-before($h, ':')) = 23">
             <xsl:choose>
               <xsl:when test="$M = 'March' and $D = '31'">April</xsl:when>
               <xsl:when test="$M = 'April' and $D = '30'">May</xsl:when>
               <xsl:when test="$M = 'May' and $D = '31'">June</xsl:when>
               <xsl:when test="$M = 'June' and $D = '30'">July</xsl:when>
               <xsl:when test="$M = 'July' and $D = '31'">August</xsl:when>
               <xsl:when test="$M = 'August' and $D = '31'">September</xsl:when>
               <xsl:when test="$M = 'September' and $D = '30'">October</xsl:when>
               <xsl:otherwise><xsl:value-of select="$M" /></xsl:otherwise>
             </xsl:choose>
           </xsl:when>
           <xsl:otherwise><xsl:value-of select="$M" /></xsl:otherwise>
         </xsl:choose>
       </xsl:variable>
       <Date><xsl:value-of select="$DOW-BST" />, <xsl:value-of select="concat($D-BST, ' ')" /> <xsl:value-of select="$M-BST" />, <xsl:value-of select="$Y" />, <xsl:value-of select="$H-BST" /> BST</Date>
     </xsl:otherwise>
   </xsl:choose>
 </xsl:template>

</xsl:stylesheet>
--
Charles Knell
cknell@xxxxxxxxxx - email



-----Original Message-----
From:     cknell@xxxxxxxxxx
Sent:     Mon, 18 Apr 2005 07:42:38 -0400
To:       xsl-list@xxxxxxxxxxxxxxxxxxxxxx
Subject:  RE: RE: RE: RE: RE: [xsl] GMT to BST converter

There are some omissions, one of which I have corrected (see the reply to Dave Pawson), but there are no hard-coded specific dates and times. Please tell me where you see them and I'll explain what I think they really are.
--
Charles Knell
cknell@xxxxxxxxxx - email



-----Original Message-----
From:     tom tom <tomxsllist@xxxxxxxxxxx>
Sent:     Mon, 18 Apr 2005 11:05:11 +0100
To:       xsl-list@xxxxxxxxxxxxxxxxxxxxxx
Subject:  RE: RE: RE: RE: [xsl] GMT to BST converter

Thanks Charles, though as you have specific dates and times hardcoded I'm 
presuming that it's only good for this year?