XSL if-子句，其中变量大于或不存在，但不小于

Question

我有一个像这样的XML文件。列表中的所有项目都有一个dateCreated。已使用的项具有dateLastUsed。没有使用过的项没有节点dateLastUsed。

<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="stripped.xsl"?>
<report>
<dateCreated>2016-05-20T12:16:11</dateCreated>
<catalog>
 <description>Older than five, never used</description>
 <call>
  <item>
   <itemID>30580004885005</itemID>
   <dateCreated>2000-02-11</dateCreated>
  </item>
 </call>
</catalog>
<catalog>
 <description>Older than five, but used threee years ago</description>
 <call>
  <item>
   <dateLastUsed>2013-10-25</dateLastUsed>
   <itemID>30580005522235</itemID>
   <dateCreated>1996-06-20</dateCreated>
  </item>
 </call>
</catalog>
<catalog>
 <description>Older than five, used more than five years ago</description>
 <call>
  <item>
   <dateLastUsed>2010-04-12</dateLastUsed>
   <itemID>30580004882085</itemID>
   <dateCreated>2000-02-01</dateCreated>
  </item>
 </call>
</catalog>
<catalog>
 <description>Older than five, but used this year</description>
 <call>
  <item>
   <dateLastUsed>2016-05-18</dateLastUsed>
   <itemID>30580004899105</itemID>
   <dateCreated>2000-03-29</dateCreated>
  </item>
 </call>
</catalog>
<catalog>
 <description>Younger than five, used less than five years ago</description>
 <call>
  <item>
   <dateLastUsed>2016-04-12</dateLastUsed>
   <itemID>30580005334920</itemID>
   <dateCreated>2015-04-25</dateCreated>
  </item>
 </call>
</catalog>
<catalog>
 <description>Younger than five, never used</description>
 <call>
  <item>
   <itemID>30580005334938</itemID>
   <dateCreated>2014-04-25</dateCreated>
  </item>
 </call>
</catalog>
</report>

我想要过滤列表，所以它只包含比5年和2a更老的项目(5年前使用)，或者2b)根本不使用的项目

1很容易用if-子句解决，2a也很容易用第二个if-子句解决，但是如何解决2b呢？

<?xml version="1.0"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="xml" indent="yes"/>
<xsl:param name="fiveYears" select="1825" />
<xsl:template match="/">
    <catalog>
        <xsl:for-each select="report/catalog">

                <xsl:variable name="daysSinceCreated">
                    <xsl:call-template name="date-difference">
                        <xsl:with-param name="date1" select="call/item/dateCreated" />
                        <xsl:with-param name="date2" select="//report/dateCreated" />
                    </xsl:call-template>
                </xsl:variable>

                <xsl:variable name="daysSinceUsed">
                    <xsl:call-template name="date-difference">
                        <xsl:with-param name="date1" select="call/item/dateLastUsed" />
                        <xsl:with-param name="date2" select="//report/dateCreated" />
                    </xsl:call-template>
                </xsl:variable>

                <xsl:if test="$daysSinceCreated > $fiveYears">

                    <xsl:if test="$daysSinceUsed > $fiveYears">

                        <itemline>
                            <description><xsl:value-of select="description"/></description>
                            <dateCreated><xsl:value-of select="call/item/dateCreated"/></dateCreated>
                            <daysSinceCreated><xsl:value-of select="$daysSinceCreated"/></daysSinceCreated>
                            <dateLastUsed><xsl:value-of select="call/item/dateLastUsed"/></dateLastUsed>
                            <daysSinceUsed><xsl:value-of select="$daysSinceUsed"/></daysSinceUsed>
                        </itemline>

                    </xsl:if>

                </xsl:if>
        </xsl:for-each>
    </catalog>
</xsl:template>

<xsl:template name="date-difference">
    <xsl:param name="date1"/>
    <xsl:param name="date2"/>
    <xsl:param name="JDN1">
        <xsl:call-template name="JDN">
            <xsl:with-param name="date" select="$date1" />
        </xsl:call-template>
    </xsl:param>
    <xsl:param name="JDN2">
        <xsl:call-template name="JDN">
            <xsl:with-param name="date" select="$date2" />
        </xsl:call-template>
    </xsl:param>
    <xsl:value-of select="$JDN2 - $JDN1"/>
</xsl:template> 

<xsl:template name="JDN">
    <xsl:param name="date"/>
    <xsl:param name="year" select="substring($date, 1, 4)"/>
    <xsl:param name="month" select="substring($date, 6, 2)"/>
    <xsl:param name="day" select="substring($date, 9, 2)"/>
    <xsl:param name="a" select="floor((14 - $month) div 12)"/>
    <xsl:param name="y" select="$year + 4800 - $a"/>
    <xsl:param name="m" select="$month + 12*$a - 3"/>
    <xsl:value-of select="$day + floor((153*$m + 2) div 5) + 365*$y + floor($y div 4) - floor($y div 100) + floor($y div 400) - 32045" />
</xsl:template> 

</xsl:stylesheet>

Answer 1

我会把你的xsl:if语句组合成这样.

<xsl:if test="($daysSinceCreated > $fiveYears and $daysSinceUsed > $fiveYears) 
  or not(string(call/item/dateLastUsed))">
    <itemline>
      <description><xsl:value-of select="description"/></description>
      <dateCreated><xsl:value-of select="call/item/dateCreated"/></dateCreated>
      <daysSinceCreated><xsl:value-of select="$daysSinceCreated"/></daysSinceCreated>
      <dateLastUsed><xsl:value-of select="call/item/dateLastUsed"/></dateLastUsed>
      <daysSinceUsed><xsl:value-of select="$daysSinceUsed"/></daysSinceUsed>
    </itemline>
</xsl:if>

您还可以使用：or $daysSinceUsed='NaN'，而不是检查string()的结果，因为您仍然在试图计算$daysSinceUsed，即使没有使用它。