XSl - 需要转型帮助

Question

我是XSLT新手，正在努力解决以下转型问题。

我有一个看起来像这样的XML ...

<Groups> 
<Group> 
    <GroupSelector>52</GroupSelector> 
    <GroupDescription>Group 52</GroupDescription> 
    <GroupValue>ABCD</GroupValue> 
</Group> 
<Group> 
    <GroupSelector>27</GroupSelector> 
    <GroupDescription>Group 27</GroupDescription> 
    <GroupValue>PQRS</GroupValue> 
</Group> 
<Group> 
    <GroupSelector>20</GroupSelector> 
    <GroupDescription>Group 20</GroupDescription> 
    <GroupValue>XYZA</GroupValue> 
</Group> 
<Group> 
    <GroupSelector>15</GroupSelector> 
    <GroupDescription>Group 15</GroupDescription> 
    <GroupValue>MNOP</GroupValue> 
</Group> 
</Groups> 

有可能是0到n个“集团

我试图使用XSLT找到一个‘集团’，其中'GroupSelector'的值是20并且像这样创建输出;

<GroupSelection ElementName="FoundGroup" Missing="false">20</GroupSelection> 
<GroupSelection ElementName="GroupDes" Missing="false">Group 20</GroupSelection> 
<GroupSelection ElementName="GroupVal" Missing="false">XYZA</GroupSelection> 

如果没有在n“集团的具有‘GroupSelector’具有值20，输出应该是这样;

<GroupSelection ElementName="FoundGroup" Missing="true"/> 
<GroupSelection ElementName="GroupDes" Missing="true"/> 
<GroupSelection ElementName="GroupVal" Missing="true"/> 

请帮忙。提前致谢。

萝拉

Answer 1

这个简单的（短，只有一个模板，无模式，无轴）和强大的（参数与任何可能的组ID工作）改造：在应用时

<xsl:stylesheet version="1.0" 
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> 
<xsl:output omit-xml-declaration="yes" indent="yes"/> 

<xsl:param name="pGroupId" select="'20'"/> 

<xsl:variable name="vGroup" select= 
    "/*/Group[GroupSelector=$pGroupId]"/> 

<xsl:template match="/"> 
    <GroupSelection ElementName="FoundGroup" 
        Missing="{not($vGroup)}"> 
     <xsl:apply-templates select="$vGroup/GroupSelector"/> 
    </GroupSelection> 
    <GroupSelection ElementName="GroupDes" 
       Missing="{not($vGroup)}"> 
     <xsl:apply-templates select="$vGroup/GroupDescription"/> 
    </GroupSelection> 
    <GroupSelection ElementName="GroupVal" 
        Missing="{not($vGroup)}"> 
     <xsl:apply-templates select="$vGroup/GroupValue"/> 
    </GroupSelection> 
</xsl:template> 
</xsl:stylesheet> 

在提供的XML文档上：

<Groups> 
<Group> 
    <GroupSelector>52</GroupSelector> 
    <GroupDescription>Group 52</GroupDescription> 
    <GroupValue>ABCD</GroupValue> 
</Group> 
<Group> 
    <GroupSelector>27</GroupSelector> 
    <GroupDescription>Group 27</GroupDescription> 
    <GroupValue>PQRS</GroupValue> 
</Group> 
<Group> 
    <GroupSelector>20</GroupSelector> 
    <GroupDescription>Group 20</GroupDescription> 
    <GroupValue>XYZA</GroupValue> 
</Group> 
<Group> 
    <GroupSelector>15</GroupSelector> 
    <GroupDescription>Group 15</GroupDescription> 
    <GroupValue>MNOP</GroupValue> 
</Group> 
</Groups> 

产生想要的，正确的结果：

<GroupSelection ElementName="FoundGroup" Missing="false">20</GroupSelection> 
<GroupSelection ElementName="GroupDes" Missing="false">Group 20</GroupSelection> 
<GroupSelection ElementName="GroupVal" Missing="false">XYZA</GroupSelection> 

如果上面的文件中，我们改变：

<GroupSelector>20</GroupSelector> 

到：

<GroupSelector>21</GroupSelector> 

并应用相同的变换在修改过的XML文档上，再次想，正确的结果产生：

<GroupSelection ElementName="FoundGroup" Missing="true"/> 
<GroupSelection ElementName="GroupDes" Missing="true"/> 
<GroupSelection ElementName="GroupVal" Missing="true"/> 

说明：使用范围：

1. <xsl:variable>

2. AVT（属性值模板）。

3. XSLT处理模型和文本节点的内置模板。

Answer 2

如果您不需要参数变换，两个模板与文字结果元素（不AVT）是不够的：

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0"> 
    <xsl:output indent="yes"/> 
    <xsl:strip-space elements="*"/> 
    <xsl:template match="text()"/> 

    <xsl:template match="/*/Group[GroupSelector=20]"> 
     <GroupSelection ElementName="FoundGroup" Missing="false"> 
      <xsl:value-of select="GroupSelector"/> 
     </GroupSelection> 
     <GroupSelection ElementName="GroupDes" Missing="false"> 
      <xsl:value-of select="GroupDescription"/> 
     </GroupSelection> 
     <GroupSelection ElementName="GroupVal" Missing="false"> 
      <xsl:value-of select="GroupValue"/> 
     </GroupSelection> 
    </xsl:template> 

    <xsl:template match="/*/Group[ 
     not(following::Group) 
     and not(preceding::Group[GroupSelector=20]) 
     and not(GroupSelector=20)]"> 
     <GroupSelection ElementName="FoundGroup" Missing="true"/> 
     <GroupSelection ElementName="GroupDes" Missing="true"/> 
     <GroupSelection ElementName="GroupVal" Missing="true"/> 
    </xsl:template> 

</xsl:stylesheet> 

否则，如果该组选择是可变的（你需要变换参数）你可以容纳有用的模板模式模式将上述溶液：

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0"> 
    <xsl:output indent="yes"/> 
    <xsl:strip-space elements="*"/> 
    <xsl:param name="selector" select="20"/> 

    <xsl:template match="/*/Group"> 
     <xsl:apply-templates select="self::*[GroupSelector=$selector]" 
      mode="selection"/> 
     <xsl:apply-templates select="self::*[ 
      not(following::Group) 
      and not(preceding::Group[GroupSelector=$selector]) 
      and not(GroupSelector=$selector)]" 
      mode="noselection"/> 
    </xsl:template> 

    <xsl:template match="Group" mode="selection"> 
     <GroupSelection ElementName="FoundGroup" Missing="false"> 
      <xsl:value-of select="GroupSelector"/> 
     </GroupSelection> 
     <GroupSelection ElementName="GroupDes" Missing="false"> 
      <xsl:value-of select="GroupDescription"/> 
     </GroupSelection> 
     <GroupSelection ElementName="GroupVal" Missing="false"> 
      <xsl:value-of select="GroupValue"/> 
     </GroupSelection> 
    </xsl:template> 

    <xsl:template match="Group" mode="noselection"> 
     <GroupSelection ElementName="FoundGroup" Missing="true"/> 
     <GroupSelection ElementName="GroupDes" Missing="true"/> 
     <GroupSelection ElementName="GroupVal" Missing="true"/> 
    </xsl:template> 

</xsl:stylesheet> 

显然，在XSLT 2.0你可以用变量直接工作，写类似：

<xsl:template match="/*/Group[GroupSelector=$selector]"> 

因此，使事情变得更简单。