XSL如何通过ID匹配值递归遍历节点

时间：2012-08-25 01:45:33

标签： xml xslt

我有以下XML示例，我需要一些帮助。 示例XML具有所需的PackageID和SourcePackageID值 匹配其他节点以查找我之后的结果。
我事先道歉，这让我很难解释。 如果您需要更多信息来了解这一点，请告诉我。 ：）

所需的结果是为CompositionPackage中的Usage元素为“TopLevel”的每个Source元素找到MaterialPackage匹配。

有些结果更容易找到，因为它们是一场比赛。其他人虽然需要通过多个匹配来循环才能找到结果。

例如：结果/ Name元素引用具有匹配PackageID的CompositionPackage的PackageName。 但是：result / Source元素需要引用匹配的CompositionPackage的SourcePackageID，然后使用其PackageID查找Material Package的PackageName。

在一个实例中，CompositionPackage / SourcePackageID直接引用MaterialPackage。尽管如果CompositionPackage的/ Operation值为“RepeatTransfer”，它会更难一点，它会在链接到MaterialPackage之前引用另一个CompositionPackage。嗯

任何帮助都会得到真正的赞赏。

示例输入XML：

<AAG version="1.1">
<Preface>
<ContentStorage>
  <MaterialPackage>
    <PackageTracks>
      <TimelineTrack>
        <TrackSegment>
            <ComponentLength>5066</ComponentLength>
        </TrackSegment>
      </TimelineTrack>
    </PackageTracks>
    <PackageName>Tape011</PackageName>
    <PackageID>urn:MM111</PackageID>
  </MaterialPackage>
  <CompositionPackage>
    <PackageTracks>
      <TimelineTrack>
        <TrackSegment>
            <SourcePackageID>urn:MM111</SourcePackageID>
            <ComponentLength>10099</ComponentLength>
        </TrackSegment>
      </TimelineTrack>
    </PackageTracks>
    <Operation>Transfer</Operation>
    <PackageName>NameABC</PackageName>
    <PackageID>urn:CC111</PackageID>
  </CompositionPackage>
  <CompositionPackage>
    <PackageTracks>
      <TimelineTrack>
        <TrackSegment>
            <SourcePackageID>urn:CC333</SourcePackageID>
            <ComponentLength>222</ComponentLength>
        </TrackSegment>
      </TimelineTrack>
    </PackageTracks>
    <Operation>RepeatTransfer</Operation>
    <PackageName>NameBCD</PackageName>
    <PackageID>urn:CC222</PackageID>
  </CompositionPackage>
  <CompositionPackage>
    <PackageTracks>
      <TimelineTrack>
        <TrackSegment>
            <SourcePackageID>urn:MM222</SourcePackageID>
            <ComponentLength>444</ComponentLength>
        </TrackSegment>
      </TimelineTrack>
    </PackageTracks>
    <Operation>Transfer</Operation>
    <PackageName>NameCDE</PackageName>
    <PackageID>urn:CC333</PackageID>
  </CompositionPackage>
  <CompositionPackage>
    <PackageTracks>
      <TimelineTrack>
        <TrackSegment>
            <SourcePackageID>urn:MM333</SourcePackageID>
            <ComponentLength>555</ComponentLength>
        </TrackSegment>
      </TimelineTrack>
    </PackageTracks>
    <Operation>Transfer</Operation>
    <PackageName>NameDEF</PackageName>
    <PackageID>urn:CC444</PackageID>
  </CompositionPackage>
  <MaterialPackage>
    <PackageTracks>
      <TimelineTrack>
        <TrackSegment>
        <ComponentLength>864</ComponentLength>
        </TrackSegment>
      </TimelineTrack>
    </PackageTracks>
    <PackageName>Tape012</PackageName>
    <PackageID>urn:MM222</PackageID>
  </MaterialPackage>
  <MaterialPackage>
    <PackageTracks>
      <TimelineTrack>
        <TrackSegment>
        <ComponentLength>864</ComponentLength>
        </TrackSegment>
      </TimelineTrack>
    </PackageTracks>
    <PackageName>Tape013</PackageName>
    <PackageID>urn:MM333</PackageID>
  </MaterialPackage>
  <CompositionPackage>
    <PackageTracks>
      <TimelineTrack>
        <TrackSegment>
            <Sequence>
                <Source>
                    <SourcePackageID>urn:CC111</SourcePackageID>
                </Source>
                <Source>
                    <SourcePackageID>urn:CC222</SourcePackageID>
                </Source>
                <Unknown>urn:0000</Unknown>
                <Source>
                    <SourcePackageID>urn:CC444</SourcePackageID>
                </Source>
            </Sequence>
        </TrackSegment>
      </TimelineTrack>
    </PackageTracks>
    <Usage>TopLevel</Usage>
    <Operation>Transfer</Operation>
    <PackageName>NameXXX</PackageName>
    <PackageID>urn:CCXXX</PackageID>
  </CompositionPackage>
</ContentStorage>
</Preface>
</AAG>

预期输出XML：

<AAG>
<Preface>
    <Book>
        <Name>NameABC</Name>
        <Source>Tape011</Source>
    </Book>
    <Book>
        <Name>NameBCD</Name>
        <Source>Tape012</Source>
    </Book>
    <Book>
        <Name>NameDEF</Name>
        <Source>Tape013</Source>
    </Book>
</Preface>
</AAG>

当前XSL：

<?xml version="1.0" encoding="UTF-8"?>

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="xml" omit-xml-declaration="no" indent="yes"/>
<xsl:strip-space elements="*"/>

<xsl:template match="@*|node()">
<xsl:copy>
    <xsl:apply-templates select="@*|node()"/>
</xsl:copy>
</xsl:template>

<xsl:template match="AAG">

<AAG>
<Preface>
    <xsl:for-each select="/AAG/Preface/ContentStorage/CompositionPackage/PackageTracks/TimelineTrack/TrackSegment/Sequence[../../../../Usage='TopLevel']">

    <xsl:choose>
        <xsl:when test = "self::Source">
            <Book>
                <Name><xsl:value-of select="../../../../*[self::CompositionPackage or self::MaterialPackage]
                                                            [PackageID=current()
                                                            /SourcePackageID]/PackageName"/></Name>

                <!-- cant work out how to do this bit 
                                    need to find MaterialPackage/PackageName from a CompositionPackage that in turn references another CompositionPackage that in turn references the MaterialPackage. -->
                                    <xsl:choose>
                <xsl:when test = "CompositionPackage[Operation='RepeatTransfer']">
                <Source><xsl:value-of select="../../../../*[self::CompositionPackage or self::MaterialPackage]
                                                            [PackageID=current()
                                                            /SourcePackageID]/PackageName"/></Source>
                </xsl:when>
                <xsl:otherwise>
                <Source><xsl:value-of select="../../../../*[self::CompositionPackage or self::MaterialPackage]
                                                            [PackageID=current()
                                                            /SourcePackageID]/PackageName"/></Source>
                </xsl:otherwise>
                </xsl:choose>
            </Book>
        </xsl:when>

    </xsl:choose>
    </xsl:for-each>

</Preface>
</AAG>

</xsl:template>

1 个答案:

答案 0 :(得分：1)

解决此问题的一种方法是使用 xsl：key 来查找 CompositionPackage 和 MaterialPackage 元素，方法是包ID 

<xsl:key name="CompositionPackage" match="CompositionPackage" use="PackageID"/>
<xsl:key name="MaterialPackage" match="MaterialPackage" use="PackageID"/>

然后，假设您定位在“顶级”来源元素上，您首先要为包选择相关的 CompositionPackage 

<xsl:apply-templates select="key('CompositionPackage', SourcePackageID)" mode="Source" />

请注意模式的使用。这将是必需的，因为在生成的xslt中，将有多个匹配 CompositionPackage 元素的模板。在第一个模板中，您可以先输出 Book 元素

<xsl:template match="CompositionPackage" mode="Source">
   <Book>
      <Name><xsl:value-of select="PackageName" /></Name>
      <Source><xsl:apply-templates select="." /></Source>
   </Book>
</xsl:template>

对于 * Source 元素，您可以启动潜在的递归查找。您可以使用另一个模板来匹配 CompositionPackage 元素，但在此文档中，您将检查该包是否在另一个 CompositionPackage 或 MaterialPackage 中。这将使用键

<xsl:template match="CompositionPackage">
  <xsl:apply-templates select="
    key('MaterialPackage',PackageTracks/TimelineTrack/TrackSegment/SourcePackageID)
    |key('CompositionPackage', PackageTracks/TimelineTrack/TrackSegment/SourcePackageID)"/>
</xsl:template>

如果是 CompositionPackage ，模板将以递归方式匹配自身。但是对于 MatertialPackage ，您只需输出包名称。

这是完整的XSLT 

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
   <xsl:output method="xml" indent="yes"/>
   <xsl:key name="CompositionPackage" match="CompositionPackage" use="PackageID"/>
   <xsl:key name="MaterialPackage" match="MaterialPackage" use="PackageID"/>

   <xsl:template match="/AAG">
      <AAG>
         <Preface>
            <xsl:apply-templates select="Preface/ContentStorage/CompositionPackage[Usage='TopLevel']/PackageTracks/TimelineTrack/TrackSegment/Sequence/Source"/>
         </Preface>
      </AAG>
   </xsl:template>

   <xsl:template match="Source">
      <xsl:apply-templates select="key('CompositionPackage', SourcePackageID)" mode="Source" />
   </xsl:template>

   <xsl:template match="CompositionPackage" mode="Source">
      <Book>
         <Name><xsl:value-of select="PackageName" /></Name>
         <Source>
            <xsl:apply-templates select="." />
         </Source>
      </Book>
   </xsl:template>

   <xsl:template match="CompositionPackage">
      <xsl:apply-templates select="key('MaterialPackage', PackageTracks/TimelineTrack/TrackSegment/SourcePackageID)|key('CompositionPackage', PackageTracks/TimelineTrack/TrackSegment/SourcePackageID)"/>
   </xsl:template>

   <xsl:template match="MaterialPackage">
      <xsl:value-of select="PackageName" />
   </xsl:template>   

   <xsl:template match="@*|node()">
      <xsl:copy>
         <xsl:apply-templates select="@*|node()"/>
      </xsl:copy>
   </xsl:template>
</xsl:stylesheet>

当应用于XSLT时，输出以下内容

<AAG>
   <Preface>
      <Book>
         <Name>NameABC</Name>
         <Source>Tape011</Source>
      </Book>
      <Book>
         <Name>NameBCD</Name>
         <Source>Tape012</Source>
      </Book>
      <Book>
         <Name>NameDEF</Name>
         <Source>Tape013</Source>
      </Book>
   </Preface>
</AAG>
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