<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

<!--

Description:

This is a date formatting utility. The named template "format-date" takes 2 parameters:

1. date - [required] takes an ISO date (2005-12-01)
2. format - [optional] takes a format string.

Format options:

Y - year in 4 digits e.g. 1981, 1992, 2008
y - year in 2 digits e.g. 81, 92, 08
M - month as a full word e.g. January, March, September
m - month in 3 letters e.g. Jan, Mar, Sep
N - month in digits without leading zero
n - month in digits with leading zero
D - day with suffix and no leading zero e.g. 1st, 23rd
d - day in digits with leading zero e.g. 01, 09, 12, 25
x - day in digits with no leading zero e.g. 1, 9, 12, 25
T - time in 24-hours e.g. 18:30
t - time in 12-hours e.g. 6:30pm
W - weekday as a full word e.g. Monday, Tuesday
w - weekday in 3 letters e.g. Mon, Tue, Wed
Z - timezone (offset)

Examples:

M       => January
d M     => 21 September
m D, y  => Sep 21st, 81
n-d-y   => 09-21-81
d/n/y   => 21/09/81
d/n/y t => 21/09/81 6:30pm

-->

<xsl:template name="format-date">
    <xsl:param name="date"/>
    <xsl:param name="format" select="'D M, Y'"/>
    <xsl:choose>
        <xsl:when test="string-length($format) &lt;= 12">
            <xsl:call-template name="date-controller">
                <xsl:with-param name="date" select="$date"/>
                <xsl:with-param name="format" select="$format"/>
            </xsl:call-template>
        </xsl:when>
        <xsl:otherwise>
            <xsl:text>Error: format parameter is not correctly set. You have: </xsl:text>
            <xsl:value-of select="string-length($format)"/>
            <xsl:text>.</xsl:text>
        </xsl:otherwise>
    </xsl:choose>
</xsl:template>

<xsl:template name="date-controller">
    <xsl:param name="date"/>
    <xsl:param name="format"/>
    <xsl:param name="letter" select="substring($format,1,1)"/>
    <xsl:param name="tletter" select="translate($letter,'DMNYTWZ','dmnytwz')"/>
    <xsl:choose>
        <xsl:when test="$tletter = 'y'">
            <xsl:call-template name="format-year">
                <xsl:with-param name="date" select="$date"/>
                <xsl:with-param name="format" select="$letter"/>
            </xsl:call-template>
        </xsl:when>
        <xsl:when test="$tletter = 'm'">
            <xsl:call-template name="format-month">
                <xsl:with-param name="date" select="$date"/>
                <xsl:with-param name="format" select="$letter"/>
            </xsl:call-template>
        </xsl:when>
        <xsl:when test="$tletter = 'n'">
            <xsl:call-template name="format-month">
                <xsl:with-param name="date" select="$date"/>
                <xsl:with-param name="format" select="$letter"/>
            </xsl:call-template>
        </xsl:when>
        <xsl:when test="$tletter = 'd'">
            <xsl:call-template name="format-day">
                <xsl:with-param name="date" select="$date"/>
                <xsl:with-param name="format" select="$letter"/>
            </xsl:call-template>
        </xsl:when>
        <xsl:when test="$tletter = 'x'">
            <xsl:call-template name="format-day">
                <xsl:with-param name="date" select="$date"/>
                <xsl:with-param name="format" select="$letter"/>
            </xsl:call-template>
        </xsl:when>
        <xsl:when test="$tletter = 't'">
            <xsl:call-template name="format-time">
                <xsl:with-param name="time" select="$date/@time"/>
                <xsl:with-param name="format" select="$letter"/>
            </xsl:call-template>
        </xsl:when>
        <xsl:when test="$tletter = 'z'">
            <xsl:call-template name="format-offset">
                <xsl:with-param name="offset" select="$date/@offset"/>
                <xsl:with-param name="format" select="$letter"/>
            </xsl:call-template>
        </xsl:when>
        <xsl:when test="$tletter = 'w'">
            <xsl:call-template name="format-weekday">
                <xsl:with-param name="weekday" select="$date/@weekday"/>
                <xsl:with-param name="format" select="$letter"/>
            </xsl:call-template>
        </xsl:when>
        <xsl:otherwise>
            <xsl:value-of select="$letter"/>
        </xsl:otherwise>
    </xsl:choose>
    <xsl:if test="$letter = not('')">
        <xsl:call-template name="date-controller">
            <xsl:with-param name="date" select="$date"/>
            <xsl:with-param name="format" select="substring($format,2)"/>
        </xsl:call-template>
    </xsl:if>
</xsl:template>

<xsl:template name="format-year">
    <xsl:param name="date"/>
    <xsl:param name="year" select="substring($date,1,4)"/>
    <xsl:param name="format" select="'y'"/>
    <xsl:choose>
        <xsl:when test="$format = 'y'">
            <xsl:value-of select="substring($year,3)"/>
        </xsl:when>
        <xsl:when test="$format = 'Y'">
            <xsl:value-of select="$year"/>
        </xsl:when>
    </xsl:choose>
</xsl:template>

<xsl:template name="format-month">
    <xsl:param name="date"/>
    <xsl:param name="month" select="format-number(substring($date,6,2), '##')"/>
    <xsl:param name="format" select="'m'"/>
    <xsl:param name="month-word">
        <xsl:choose>
            <xsl:when test="$month = 01">January</xsl:when>
            <xsl:when test="$month = 02">February</xsl:when>
            <xsl:when test="$month = 03">March</xsl:when>
            <xsl:when test="$month = 04">April</xsl:when>
            <xsl:when test="$month = 05">May</xsl:when>
            <xsl:when test="$month = 06">Juny</xsl:when>
            <xsl:when test="$month = 07">July</xsl:when>
            <xsl:when test="$month = 08">August</xsl:when>
            <xsl:when test="$month = 09">September</xsl:when>
            <xsl:when test="$month = 10">October</xsl:when>
            <xsl:when test="$month = 11">November</xsl:when>
            <xsl:when test="$month = 12">December</xsl:when>
        </xsl:choose>
    </xsl:param>
    <xsl:choose>
        <xsl:when test="$format = 'm'">
            <xsl:value-of select="substring($month-word, 1,3)"/>
        </xsl:when>
        <xsl:when test="$format = 'M'">
            <xsl:value-of select="$month-word"/>
        </xsl:when>
        <xsl:when test="$format = 'n'">
            <xsl:value-of select="format-number($month, '00')"/>
        </xsl:when>
        <xsl:when test="$format = 'N'">
            <xsl:value-of select="format-number($month, '0')"/>
        </xsl:when>
    </xsl:choose>
</xsl:template>

<xsl:template name="format-day">
    <xsl:param name="date"/>
    <xsl:param name="day" select="format-number(substring($date,9,2),'00')"/>
    <xsl:param name="format" select="'d'"/>
    <xsl:param name="suffix">
        <xsl:choose>
            <xsl:when test="(substring($day,2) = 1) and not(substring($day,1,1) = 1)">st</xsl:when>
            <xsl:when test="(substring($day,2) = 2) and not(substring($day,1,1) = 1)">nd</xsl:when>
            <xsl:when test="(substring($day,2) = 3) and not(substring($day,1,1) = 1)">rd</xsl:when>
            <xsl:otherwise>th</xsl:otherwise>
        </xsl:choose>
    </xsl:param>
    <xsl:choose>
        <xsl:when test="$format = 'd'">
            <xsl:value-of select="$day"/>
        </xsl:when>
        <xsl:when test="$format = 'x'">
            <xsl:value-of select="format-number($day,'0')"/>
        </xsl:when>
        <xsl:when test="$format = 'D'">
            <xsl:value-of select="format-number($day,'0')"/>
            <xsl:value-of select="$suffix"/>
        </xsl:when>
    </xsl:choose>
</xsl:template>

<xsl:template name="format-time">
    <xsl:param name="time"/>
    <xsl:param name="format" select="'T'"/>
    <xsl:choose>
        <xsl:when test="$format = 'T'">
            <xsl:value-of select="$time"/>
        </xsl:when>
        <xsl:when test="$format = 't'">
            <xsl:value-of select="$time"/>
        </xsl:when>
    </xsl:choose>
</xsl:template>

<xsl:template name="format-offset">
    <xsl:param name="offset"/>
    <xsl:param name="format" select="'Z'"/>
    <xsl:choose>
        <xsl:when test="$format = 'Z'">
            <xsl:value-of select="$offset"/>
        </xsl:when>
        <xsl:when test="$format = 'z'">
            <xsl:value-of select="$offset"/>
        </xsl:when>
    </xsl:choose>
</xsl:template>

<xsl:template name="format-weekday">
    <xsl:param name="weekday"/>
    <xsl:param name="format" select="'W'"/>
    <xsl:param name="result">
    <xsl:choose>
        <xsl:when test="$weekday = 1">Monday</xsl:when>
        <xsl:when test="$weekday = 2">Tuesday</xsl:when>
        <xsl:when test="$weekday = 3">Wednesday</xsl:when>
        <xsl:when test="$weekday = 4">Thursday</xsl:when>
        <xsl:when test="$weekday = 5">Friday</xsl:when>
        <xsl:when test="$weekday = 6">Saturday</xsl:when>
        <xsl:when test="$weekday = 7">Sunday</xsl:when>
    </xsl:choose>
    </xsl:param>
    <xsl:choose>
        <xsl:when test="$format = 'W'">
            <xsl:value-of select="$result"/>
        </xsl:when>
        <xsl:when test="$format = 'w'">
            <xsl:value-of select="substring($result,1,3)"/>
        </xsl:when>
    </xsl:choose>
</xsl:template>

</xsl:stylesheet>
