XSLT技术问询：如何按Person/UsrAddress/Code正确分组Reservation节点

问题场景 #

现有如下XML导出文档：

<?xml version='1.0' encoding='UTF-8'?>
<document>
    <header>
        <creation-date>2022-08-09T08:46:00</creation-date>
        <SequenceOfDocument>10</SequenceOfDocument>
    </header>
    <businessobjects>
        <Reservation>
            <BeginDateTime>2022-07-29T16:00:00</BeginDateTime>
            <OrderNumber>606.00</OrderNumber>
            <Person>
                <UsrAddress>
                    <Code>0393</Code>
                </UsrAddress>
            </Person>
            <TotalActualCostExclVAT>30.00</TotalActualCostExclVAT>
            <ParentOrderRef/>
        </Reservation>
        <Reservation>
            <BeginDateTime>2022-07-29T16:00:00</BeginDateTime>
            <OrderNumber>606.01</OrderNumber>
            <RefBODefinitionUserDefined>UsrReservationEquipment</RefBODefinitionUserDefined>
            <Person>
                <UsrAddress>
                    <Code>0393</Code>
                </UsrAddress>
            </Person>
            <TotalActualCostExclVAT>40.00</TotalActualCostExclVAT>
            <ParentOrderRef>606.00</ParentOrderRef>
        </Reservation>
        
        <Reservation>
            <BeginDateTime>2022-07-29T16:00:00</BeginDateTime>
            <OrderNumber>607.00</OrderNumber>
            <RefBODefinitionUserDefined>UsrReservationEquipment</RefBODefinitionUserDefined>
            <Person>
                <UsrAddress>
                    <Code>0500</Code>
                </UsrAddress>
            </Person>
            <TotalActualCostExclVAT>50.00</TotalActualCostExclVAT>
            <ParentOrderRef></ParentOrderRef>
        </Reservation>
    </businessobjects>
</document>

需要将所有Reservation节点按Person/UsrAddress/Code分组，生成如下结构的XML：

<SalesOrderHeader>
    <SalesOrderHeaderFields>
        <CustomerNumber>0393</CustomerNumber>
    </SalesOrderHeaderFields>
    <ItemFields>
        <_USERFIELD1>606.00</_USERFIELD1>
    </ItemFields>
    <ItemFields>
        <_USERFIELD1>606.01</_USERFIELD1>
    </ItemFields>
</SalesOrderHeader>

<SalesOrderHeader>
    <SalesOrderHeaderFields>
        <CustomerNumber>0500</CustomerNumber>
    </SalesOrderHeaderFields>
    <ItemFields>
        <_USERFIELD1>607.00</_USERFIELD1>
    </ItemFields>
</SalesOrderHeader>

错误原因分析 #

原尝试的代码中，group-by="/Person/UsrAddress/Code"使用了绝对路径，会从XML根节点开始查找Person元素，而当前上下文是Reservation节点，正确的路径应该是相对路径Person/UsrAddress/Code。此外，需确保使用支持XSLT 2.0及以上版本的处理器（如Saxon），因为<xsl:for-each-group>是XSLT 2.0引入的特性。

完整XSLT解决方案 #

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <!-- 匹配根节点 -->
    <xsl:template match="/document">
        <!-- 遍历businessobjects下的Reservation节点，按Person/UsrAddress/Code分组 -->
        <xsl:for-each-group select="businessobjects/Reservation" group-by="Person/UsrAddress/Code">
            <!-- 生成每个分组的SalesOrderHeader -->
            <SalesOrderHeader>
                <SalesOrderHeaderFields>
                    <!-- 使用分组键作为CustomerNumber -->
                    <CustomerNumber><xsl:value-of select="current-grouping-key()"/></CustomerNumber>
                </SalesOrderHeaderFields>
                <!-- 遍历当前分组内的所有Reservation节点 -->
                <xsl:for-each select="current-group()">
                    <ItemFields>
                        <_USERFIELD1><xsl:value-of select="OrderNumber"/></_USERFIELD1>
                    </ItemFields>
                </xsl:for-each>
            </SalesOrderHeader>
            <!-- 添加换行分隔不同的SalesOrderHeader -->
            <xsl:text>&#10;</xsl:text>
        </xsl:for-each-group>
    </xsl:template>
</xsl:stylesheet>

关键说明 #

• group-by="Person/UsrAddress/Code"：基于当前Reservation节点下的相对路径获取分组键，确保正确匹配每个Reservation对应的地址码。
• current-grouping-key()：直接获取当前分组的键值（即地址码），用于填充CustomerNumber。
• current-group()：返回当前分组内的所有Reservation节点，遍历生成对应的ItemFields。

内容的提问来源于stack exchange，提问作者Ma Kul