XSLT 2.0按值和元素分组XML节点并处理特定节点值问题

需求概述 #

• 按applicationId对<Application>节点进行分组
• 分组后按子元素名称去重，每个元素仅保留一个实例
• 针对<cust_overallduedilligencestatus>节点，若同一applicationId分组内存在id为197280的项，最终保留该值；无此值则保留原有内容

输入XML #

<?xml version='1.0' encoding='UTF-8'?>
<Applications>
    <Application>
        <applicationId>280</applicationId>
        <cust_IDCheckIDCollation>
            <Option>
                <id>197249</id>
            </Option>
        </cust_IDCheckIDCollation>
        <cust_overallduedilligencestatus>
            <Option>
                <id>197276</id>
            </Option>
        </cust_overallduedilligencestatus>
    </Application>
    <Application>
        <applicationId>292</applicationId>
        <cust_IDCheckIDCollation>
            <Option>
                <id>197249</id>
            </Option>
        </cust_IDCheckIDCollation>
        <cust_overallduedilligencestatus>
            <Option>
                <id>197276</id>
            </Option>
        </cust_overallduedilligencestatus>
    </Application>
    <Application>
        <applicationId>280</applicationId>
        <cust_OnlineReferenceCheck>
            <Option>
                <id>197249</id>
            </Option>
        </cust_OnlineReferenceCheck>
        <cust_overallduedilligencestatus>
            <Option>
                <id>197276</id>
            </Option>
        </cust_overallduedilligencestatus>
    </Application>
    <Application>
        <applicationId>292</applicationId>
        <cust_OnlineReferenceCheck>
            <Option>
                <id>197249</id>
            </Option>
        </cust_OnlineReferenceCheck>
        <cust_overallduedilligencestatus>
            <Option>
                <id>197276</id>
            </Option>
        </cust_overallduedilligencestatus>
    </Application>
    <Application>
        <applicationId>280</applicationId>
        <cust_AustralianWorkRights>
            <Option>
                <id>197250</id>
            </Option>
        </cust_AustralianWorkRights>
        <cust_overallduedilligencestatus>
            <Option>
                <id>197276</id>
            </Option>
        </cust_overallduedilligencestatus>
    </Application>
    <Application>
        <applicationId>292</applicationId>
        <cust_AustralianWorkRights>
            <Option>
                <id>197250</id>
            </Option>
        </cust_AustralianWorkRights>
        <cust_overallduedilligencestatus>
            <Option>
                <id>197276</id>
            </Option>
        </cust_overallduedilligencestatus>
    </Application>
    <Application>
        <applicationId>280</applicationId>
        <cust_NationalPoliceCheck>
            <Option>
                <id>197249</id>
            </Option>
        </cust_NationalPoliceCheck>
        <cust_overallduedilligencestatus>
            <Option>
                <id>197280</id>
            </Option>
        </cust_overallduedilligencestatus>
    </Application>
    <Application>
        <applicationId>292</applicationId>
        <cust_NationalPoliceCheck>
            <Option>
                <id>197249</id>
            </Option>
        </cust_NationalPoliceCheck>
        <cust_overallduedilligencestatus>
            <Option>
                <id>197276</id>
            </Option>
        </cust_overallduedilligencestatus>
    </Application>
</Applications>

期望输出XML #

<Applications>
    <Application>
        <applicationId>280</applicationId>
        <cust_IDCheckIDCollation>
            <Option>
                <id>197249</id>
            </Option>
        </cust_IDCheckIDCollation>
        <cust_overallduedilligencestatus>
            <Option>
                <id>197280</id>
            </Option>
        </cust_overallduedilligencestatus>
        <cust_OnlineReferenceCheck>
            <Option>
                <id>197249</id>
            </Option>
        </cust_OnlineReferenceCheck>
        <cust_AustralianWorkRights>
            <Option>
                <id>197250</id>
            </Option>
        </cust_AustralianWorkRights>
        <cust_NationalPoliceCheck>
            <Option>
                <id>197249</id>
            </Option>
        </cust_NationalPoliceCheck>
    </Application>
    <Application>
        <applicationId>292</applicationId>
        <cust_IDCheckIDCollation>
            <Option>
                <id>197249</id>
            </Option>
        </cust_IDCheckIDCollation>
        <cust_overallduedilligencestatus>
            <Option>
                <id>197280</id>
            </Option>
        </cust_overallduedilligencestatus>
        <cust_OnlineReferenceCheck>
            <Option>
                <id>197249</id>
            </Option>
        </cust_OnlineReferenceCheck>
        <cust_AustralianWorkRights>
            <Option>
                <id>197250</id>
            </Option>
        </cust_AustralianWorkRights>
        <cust_NationalPoliceCheck>
            <Option>
                <id>197249</id>
            </Option>
        </cust_NationalPoliceCheck>
    </Application>
</Applications>

现有XSLT代码（仅实现分组去重） #

<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="xml" indent="yes"/>
<xsl:template match="/Applications">
    <xsl:copy>
        <xsl:for-each-group select="Application" group-by="applicationId">
            <xsl:copy>
                <xsl:copy-of select="applicationId"/>
                <xsl:for-each-group select="current-group()/(* except applicationId)" group-by="name()">
                    <xsl:copy-of select="current-group()[1]"/>
                </xsl:for-each-group>
            </xsl:copy>
        </xsl:for-each-group>
    </xsl:copy>
</xsl:template>   
</xsl:stylesheet>

解决方案：修改后的XSLT代码 #

核心思路：在子元素分组时，对<cust_overallduedilligencestatus>节点单独判断，优先保留id=197280的项，其他元素按原有逻辑取第一个实例。

<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:output method="xml" indent="yes"/>
    
    <xsl:template match="/Applications">
        <xsl:copy>
            <!-- 按applicationId分组 -->
            <xsl:for-each-group select="Application" group-by="applicationId">
                <xsl:copy>
                    <xsl:copy-of select="applicationId"/>
                    <!-- 按子元素名称分组去重 -->
                    <xsl:for-each-group select="current-group()/(* except applicationId)" group-by="name()">
                        <xsl:choose>
                            <!-- 处理cust_overallduedilligencestatus节点 -->
                            <xsl:when test="current-grouping-key() = 'cust_overallduedilligencestatus'">
                                <!-- 优先选取id=197280的项，不存在则取第一个 -->
                                <xsl:copy-of select="current-group()[Option/id = '197280'] | current-group()[not(current-group()[Option/id = '197280'])][1]"/>
                            </xsl:when>
                            <!-- 其他元素直接取第一个 -->
                            <xsl:otherwise>
                                <xsl:copy-of select="current-group()[1]"/>
                            </xsl:otherwise>
                        </xsl:choose>
                    </xsl:for-each-group>
                </xsl:copy>
            </xsl:for-each-group>
        </xsl:copy>
    </xsl:template>   
</xsl:stylesheet>

关键逻辑说明 #

• 使用current-grouping-key()判断当前分组的元素名称是否为cust_overallduedilligencestatus
• 用current-group()[Option/id = '197280']筛选出该分组内id为197280的节点，若存在则保留；若不存在则通过current-group()[not(...)][1]取第一个节点
• 其他元素保持原有去重逻辑，取分组内第一个实例

内容的提问来源于stack exchange，提问作者Madhu N G