寻求XSLT 2.0分组方案：复杂XML结构转换需求

Hey there! Let's tackle this XML transformation problem step by step using XSLT 2.0's grouping features. First, let's break down the core logic we need to implement based on your source and target structures:

Key Grouping & Mapping Requirements #

• First, group all <rule> elements by the value of <cond colId="1"> (this becomes our RuleIdVal)
• Within each RuleId group, group rules by the value of <act colId="2"> (this becomes our Group Name)
• For each rule in a Group, generate an <EventRule> by mapping values from specific <act> elements using their colId attributes

Complete XSLT Code #

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="2.0"
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:dt="http:///com/tibco/cep/decision/table/model/DecisionTable.ecore"
    exclude-result-prefixes="dt">

    <xsl:output method="xml" indent="yes" encoding="UTF-8"/>

    <!-- Match the root decisionTable element -->
    <xsl:template match="/dt:decisionTable">
        <!-- First level grouping: group rules by RuleId (cond colId="1" expr) -->
        <xsl:for-each-group select="dt:rule" group-by="dt:cond[@colId='1']/@expr">
            <RuleId>
                <RuleIdVal><xsl:value-of select="current-grouping-key()"/></RuleIdVal>
                
                <!-- Second level grouping: group current rules by GroupName (act colId="2" expr) -->
                <xsl:for-each-group select="current-group()" group-by="dt:act[@colId='2']/@expr">
                    <Group>
                        <Name><xsl:value-of select="current-grouping-key()"/></Name>
                        
                        <!-- Generate EventRule for each rule in the current group -->
                        <xsl:for-each select="current-group()">
                            <EventRule>
                                <Sequence><xsl:value-of select="dt:act[@colId='7']/@expr"/></Sequence>
                                <LValue><xsl:value-of select="dt:act[@colId='4']/@expr"/></LValue>
                                <Operator><xsl:value-of select="dt:act[@colId='5']/@expr"/></Operator>
                                <Rvalue><xsl:value-of select="dt:act[@colId='6']/@expr"/></Rvalue>
                                <Action><xsl:value-of select="dt:act[@colId='3']/@expr"/></Action>
                                <Status></Status>
                            </EventRule>
                        </xsl:for-each>
                    </Group>
                </xsl:for-each-group>
            </RuleId>
        </xsl:for-each-group>
    </xsl:template>

    <!-- Default template to ignore unneeded nodes like <columns> -->
    <xsl:template match="*"/>
</xsl:stylesheet>

Key Details Explained #

1. Namespace Handling: The source XML uses a custom namespace, so we declare it with the prefix dt in the stylesheet. This ensures we can correctly select elements like dt:rule and dt:cond without missing them.
2. Two-Level Grouping:
   • The outer xsl:for-each-group clusters all rules by their RuleId value (from the first condition column)
   • The inner xsl:for-each-group further groups rules within each RuleId set by their GroupName (from the second action column)
3. Value Mapping: For each rule in the inner group, we pull values directly from <act> elements using their colId attributes to match the target XML's structure (e.g., colId="7" maps to <Sequence>)
4. Clean Output: The default template <xsl:template match="*"/> ensures non-relevant elements like <columns> from the source don't appear in the final output.

This stylesheet will generate exactly the target XML structure you requested, with proper grouping and value mapping.

内容的提问来源于stack exchange，提问作者bala