在XSLT中使用函数还是使用模板？

Question

在XSLT中函数和模板的优缺点是什么？

我想发送一个unix-timestamp，然后得到一个类似于“今天”、“明天”或“下周”的答案。哪种方法最适合这样做？

Answer 1

选择<xsl:function>而不是命名模板的主要原因是函数的可组合性要高得多。

编写一个生成所需结果的 <xsl:function> 非常容易和方便

 <xsl:function name="my:when" as="xs:string">
  <xsl:param name="pDateTime" as="xs:dateTime"/>

  <xsl:sequence select=
  "for $vToday in xs:dateTime(current-date()),
       $vTomorrow in $vToday
                    + xs:dayTimeDuration('P1D'),
       $vDayAfterTomorrow in $vTomorrow
                    + xs:dayTimeDuration('P1D'),
       $vNextWeek in $vToday
                    + 7* xs:dayTimeDuration('P1D'),
       $vNextFortnight in $vNextWeek
                    + 7* xs:dayTimeDuration('P1D')

       return
         if($pDateTime lt $vToday)
           then 'in the Past'
           else if($pDateTime lt $vTomorrow)
             then 'Today'
             else if($pDateTime lt $vDayAfterTomorrow)
              then 'Tomorrow'
             else if($pDateTime lt $vNextWeek)
              then 'This week'
             else if($pDateTime lt $vNextFortnight)
              then 'Next week'
              else 'In the Future'
  "/>
 </xsl:function>

这里的是一个完整的转换

<xsl:stylesheet version="2.0"
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
 xmlns:xs="http://www.w3.org/2001/XMLSchema"
 xmlns:my="my:my">
 <xsl:output omit-xml-declaration="yes"/>

 <xsl:template match="/">
  <xsl:sequence select="my:when(current-dateTime())"/>,
  <xsl:sequence select="my:when(current-dateTime()
                               +xs:dayTimeDuration('P1D'))"/>,
  <xsl:sequence select="my:when(current-dateTime()
                               +xs:dayTimeDuration('P2D'))"/>,
  <xsl:sequence select="my:when(current-dateTime()
                               +xs:dayTimeDuration('P3D'))"/>,
  <xsl:sequence select="my:when(current-dateTime()
                               +xs:dayTimeDuration('P4D'))"/>,
  <xsl:sequence select="my:when(current-dateTime()
                               +xs:dayTimeDuration('P5D'))"/>,
  <xsl:sequence select="my:when(current-dateTime()
                               +xs:dayTimeDuration('P6D'))"/>,
  <xsl:sequence select="my:when(current-dateTime()
                               +xs:dayTimeDuration('P7D'))"/>,
  <xsl:sequence select="my:when(current-dateTime()
                               +xs:dayTimeDuration('P8D'))"/>,
  <xsl:sequence select="my:when(current-dateTime()
                               +xs:dayTimeDuration('P9D'))"/>
 </xsl:template>

 <xsl:function name="my:when" as="xs:string">
  <xsl:param name="pDateTime" as="xs:dateTime"/>

  <xsl:sequence select=
  "for $vToday in xs:dateTime(current-date()),
       $vTomorrow in $vToday
                    + xs:dayTimeDuration('P1D'),
       $vDayAfterTomorrow in $vTomorrow
                    + xs:dayTimeDuration('P1D'),
       $vNextWeek in $vToday
                    + 7* xs:dayTimeDuration('P1D'),
       $vNextFortnight in $vNextWeek
                    + 7* xs:dayTimeDuration('P1D')

       return
         if($pDateTime lt $vToday)
           then 'in the Past'
           else if($pDateTime lt $vTomorrow)
             then 'Today'
             else if($pDateTime lt $vDayAfterTomorrow)
              then 'Tomorrow'
             else if($pDateTime lt $vNextWeek)
              then 'This week'
             else if($pDateTime lt $vNextFortnight)
              then 'Next week'
              else 'In the Future'
  "/>
 </xsl:function>
</xsl:stylesheet>

当应用此转换(对任何文档--未使用)时，将生成所需的正确结果

  Today,
  Tomorrow,
  This week,
  This week,
  This week,
  This week,
  This week,
  Next week,
  Next week,
  Next week

Answer 2

在这种情况下，外部函数是最合适的。

XSLT最适合模式匹配和转换，而不是计算。