Question

这是我上一个问题的跟进； Sorting on attribute collected from reference list

现在，我添加了两个VisitedCity元素，它们位于世界的一部分中，未在用于排序的参考列表中列出。我希望所有这些元素最终都在列表的末尾，并按第二个（日期）键在内部排序。

这是更新的源xml：

<?xml version="1.0" encoding="UTF-8"?> <Atlas>
    <Cities>
        <City id="1" worldPart="Africa">
            <Name>Luxor</Name>
            <Founded>-3200</Founded>
            <Location>Egypt</Location>
        </City>
        <City id="2" worldPart="Africa">
            <Name>Tripoli</Name>
            <Founded>-700</Founded>
            <Location>Libya</Location>
        </City>
        <City id="3" worldPart="Americas">
            <Name>Cholula</Name>
            <Founded>-200</Founded>
            <Location>Mexico</Location>
        </City>
        <City id="4" worldPart="Americas">
            <Name>Flores</Name>
            <Founded>-1000</Founded>
            <Location>Guatemala</Location>
        </City>
        <City id="5" worldPart="Europe">
            <Name>Argos</Name>
            <Founded>-5000</Founded>
            <Location>Greece</Location>
        </City>
        <City id="6" worldPart="Europe">
            <Name>Athens</Name>
            <Founded>-4000</Founded>
            <Location>Greece</Location>
        </City>
        <City id="7" worldPart="Asia">
            <Name>Varanasi</Name>
            <Founded>-1800</Founded>
            <Location>India</Location>
        </City>
        <City id="8" worldPart="Asia">
            <Name>Jakarta</Name>
            <Founded>397</Founded>
            <Location>Indonesia</Location>
        </City>
    </Cities>
    <VisitedCities lastUpdate="2018-09-10">
        <VisitedCity cityID="6">
            <Date>1883-08-26</Date>
            <Visitor>Dora</Visitor>
        </VisitedCity>
        <VisitedCity cityID="3">
            <Date>1907-01-02</Date>
            <Visitor>Nemo</Visitor>
        </VisitedCity>
        <VisitedCity cityID="4">
            <Date>1940-02-08</Date>
            <Visitor>Jimenez</Visitor>
        </VisitedCity>
        <VisitedCity cityID="7">
            <Date>2006-09-11</Date>
            <Visitor>Cook</Visitor>
        </VisitedCity>
        <VisitedCity cityID="2">
            <Date>1886-06-10</Date>
            <Visitor>James T. Kirk</Visitor>
        </VisitedCity>
        <VisitedCity cityID="8">
            <Date>1996-11-10</Date>
            <Visitor>Andree</Visitor>
        </VisitedCity>
    </VisitedCities> </Atlas>

所需的输出如下：

<?xml version="1.0" encoding="UTF-8"?>
<Atlas>
    <Cities>
        <City id="1" worldPart="Africa">
            <Name>Luxor</Name>
            <Founded>-3200</Founded>
            <Location>Egypt</Location>
        </City>
        <City id="2" worldPart="Africa">
            <Name>Tripoli</Name>
            <Founded>-700</Founded>
            <Location>Libya</Location>
        </City>
        <City id="3" worldPart="Americas">
            <Name>Cholula</Name>
            <Founded>-200</Founded>
            <Location>Mexico</Location>
        </City>
        <City id="4" worldPart="Americas">
            <Name>Flores</Name>
            <Founded>-1000</Founded>
            <Location>Guatemala</Location>
        </City>
        <City id="5" worldPart="Europe">
            <Name>Argos</Name>
            <Founded>-5000</Founded>
            <Location>Greece</Location>
        </City>
        <City id="6" worldPart="Europe">
            <Name>Athens</Name>
            <Founded>-4000</Founded>
            <Location>Greece</Location>
        </City>
        <City id="7" worldPart="Asia">
            <Name>Varanasi</Name>
            <Founded>-1800</Founded>
            <Location>India</Location>
        </City>
        <City id="8" worldPart="Asia">
            <Name>Jakarta</Name>
            <Founded>397</Founded>
            <Location>Indonesia</Location>
        </City>
    </Cities>
    <VisitedCities lastUpdate="2018-09-10">
        <VisitedCity cityID="2">
            <Date>1886-06-10</Date>
            <Visitor>James T. Kirk</Visitor>
        </VisitedCity>
        <VisitedCity cityID="6">
            <Date>1883-08-26</Date>
            <Visitor>Dora</Visitor>
        </VisitedCity>
        <VisitedCity cityID="3">
            <Date>1907-01-02</Date>
            <Visitor>Nemo</Visitor>
        </VisitedCity>
        <VisitedCity cityID="4">
            <Date>1940-02-08</Date>
            <Visitor>Jimenez</Visitor>
        </VisitedCity>
        <VisitedCity cityID="8">
            <Date>1996-11-10</Date>
            <Visitor>Andree</Visitor>
        </VisitedCity>
        <VisitedCity cityID="7">
            <Date>2006-09-11</Date>
            <Visitor>Cook</Visitor>
        </VisitedCity>
    </VisitedCities>
</Atlas>

据我了解，Martin Honnen在previous solution中使用的index-of（）将包含空序列值，这些值会导致这些城市被丢弃或排在所有其他城市之前。有没有一种方法可以定义一个“后备”值来代替这些空值？还是我需要建立一个完整的参考列表来避免这种情况？

还是我完全误解了index-of（）？请帮助我对这些不幸的城市进行分类！我使用XSLT 2.0。

Answer 1

如果没有找到该项目，index-of函数将返回空序列，因此您可以决定进行检查，并在这种情况下返回count($sort-order) + 1，XPath中的一种紧凑方法是

<xsl:sort select="(index-of($sort-order, key('city-by-id', @cityID)/@worldPart), count($sort-order) + 1)[1]"/>

https://xsltfiddle.liberty-development.net/eiZQaFJ/1

更长但也许更容易掌握的版本是使用`

if (empty(index-of($sort-order, key('city-by-id', @cityID)/@worldPart))) then count($sort-order) + 1 else index-of($sort-order, key('city-by-id', @cityID)/@worldPart)

排序类别不在参考列表中的元素

1 个答案: