xpath - if else结构

Question

我正在尝试使用xpath.

这是我用于实验的xml:

<moves>
    <roll player="1">6</roll>
    <piece nr="1" player="1" field="1"/>
    <roll player="2">4</roll>
    <roll player="2">6</roll>
    <piece nr="5" player="2" field="11"/>
    <roll player="1">4</roll>
    <piece nr="1" player="1" field="5"/>
    <roll player="2">6</roll>
    <piece nr="5" player="2" field="17"/>
    <roll player="1">6</roll>
    <piece nr="2" player="1" field="1"/>
    <roll player="2">6</roll>
    <piece nr="6" player="2" field="11"/>
</moves>

那么如何在xpath中实现if else呢？

就像第二个动作来自玩家一,然后做f.ex:给它回来......

更新1:

好的,这就是我的意思:

boolean(/game/moves/roll[2]/@player=1

如果第二个元素是玩家1,那么这会让我回来,所以现在我想添加一个其他路径,如果它会是？那么如何添加呢？

Answer 1

使用XPath 2.0表达式,如下所示:

if(/moves/roll[2]/@player eq '1')
  then 'player: 1'
  else ('player: ', data(/moves/roll[2]/@player) )

基于XSLT 2.0的验证:

<xsl:stylesheet version="2.0"
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
 xmlns:xs="http://www.w3.org/2001/XMLSchema">
 <xsl:output method="text"/>

 <xsl:template match="/">
  <xsl:sequence select=
  "if(/moves/roll[2]/@player eq '1')
      then 'player: 1'
      else ('player: ', data(/moves/roll[2]/@player) )
  "/>
 </xsl:template>
</xsl:stylesheet>

在提供的XML文档上应用此转换时:

<moves>
    <roll player="1">6</roll>
    <piece nr="1" player="1" field="1"/>
    <roll player="2">4</roll>
    <roll player="2">6</roll>
    <piece nr="5" player="2" field="11"/>
    <roll player="1">4</roll>
    <piece nr="1" player="1" field="5"/>
    <roll player="2">6</roll>
    <piece nr="5" player="2" field="17"/>
    <roll player="1">6</roll>
    <piece nr="2" player="1" field="1"/>
    <roll player="2">6</roll>
    <piece nr="6" player="2" field="11"/>
</moves>

评估上面的XPath表达式,并将评估结果复制到输出:

player:  2