XSLT：使用 XSLT 处理分层 XML 数据

Question

我有以下 XML 文档。 每个节点下有许多子节点，但我只对其中的几个感兴趣。 我的目标是在其上运行 xslt 以生成仅包含我对它们感兴趣的元素的 Json 输出。

我采用的方法是首先将其作为 XML 处理（应用所有数据转换、重命名、仅输出我感兴趣的元素等）然后应用另一个 xslt 将其转换为 Json（我在网上找到了一些现成的 xslt，可以去做）。

我现在的问题主要在递归部分，我无法正确完成，我尝试了 for-each/apply-templates/call-template 但我仍然很难解决它。

<MainDoc>
    <MetaData>
        <Name>MainDoc Name</Name>
        <Date>MainDoc Date</Date> <!--not interested in this element-->
    </MetaData>
    <ContentList>
        <Content/>
        <Content/>
        <Content><!--Want to process last content only-->
            <BuildList>
                <Build>
                    <Steps>
                        <Step><!--want to process all of them-->
                            <StepContentParent>
                                <StepContent>
                                    <Title>myTitle1</Title>
                                    <Details>myDetails1</Details>
                                    <Date>Step Date</Date> <!--not interested in this element-->
                                </StepContent>
                            </StepContentParent>
                            <Steps><!--Could be empty or could be the same as the previous Steps (recursion ) -->
                                <Step><!--want to process all of them-->
                                    <StepContentParent>
                                        <StepContent>
                                            <Title>myTitle1.1</Title>
                                            <Details>myDetails1.1</Details>
                                        </StepContent>
                                    </StepContentParent>
                                    <Steps/><!--Could be empty or could be the same as the previous Steps (recursion ) -->
                                    <SubDoc><!-- could be empty -->
                                        <SubDocInstance>
                                            <DocInstance>
                                                <MainDoc><!-- Same as Root (recursion ) -->
                                                    <MetaData>
                                                        <Name>Sub Doc Name</Name>
                                                    </MetaData>
                                                    <ContentList>
                                                        <Content/>
                                                        <Content/>
                                                        <Content><!--Want to process last content only-->
                                                            <BuildList>
                                                                <Build>
                                                                    <Steps>
                                                                        <Step><!--want to process all of them-->
                                                                            <StepContentParent>
                                                                                <StepContent>
                                                                                    <Title>Sub Doc myTitle1</Title>
                                                                                    <Details>Sub Doc myDetails1</Details>
                                                                                </StepContent>
                                                                            </StepContentParent>
                                                                            <Steps><!--Could be empty or could be the same as the previous Steps (recursion ) -->
                                                                                <Step><!--want to process all of them-->
                                                                                    <StepContentParent>
                                                                                        <StepContent>
                                                                                            <Title>Sub Doc myTitle1.1</Title>
                                                                                            <Details>Sub Doc myDetails1.1</Details>
                                                                                        </StepContent>
                                                                                    </StepContentParent>
                                                                                    <Steps/><!--Could be empty or could be the same as the previous Steps (recursion ) -->
                                                                                    <SubDoc><!-- could be empty -->
                                                                                        <SubDocInstance>
                                                                                            <DocInstance>
                                                                                                <MainDoc/><!-- Same as Root (recursion ) -->
                                                                                            </DocInstance>
                                                                                        </SubDocInstance>
                                                                                    </SubDoc>
                                                                                </Step>
                                                                                <step/>
                                                                                <step/>
                                                                            </Steps>
                                                                            <SubDoc><!-- could be empty -->
                                                                                <SubDocInstance>
                                                                                    <DocInstance>
                                                                                        <MainDoc/><!-- Same as Root (recursion ) -->
                                                                                    </DocInstance>
                                                                                </SubDocInstance>
                                                                            </SubDoc>
                                                                        </Step>
                                                                    </Steps>
                                                                </Build>
                                                            </BuildList>
                                                        </Content>
                                                    </ContentList>
                                                </MainDoc>
                                            </DocInstance>
                                        </SubDocInstance>
                                    </SubDoc>
                                </Step>
                                <step/>
                                <step/>
                            </Steps>
                            <SubDoc><!-- could be empty -->
                                <SubDocInstance>
                                    <DocInstance>
                                        <MainDoc/><!-- Same as Root (recursion ) -->
                                    </DocInstance>
                                </SubDocInstance>
                            </SubDoc>
                        </Step>
                        <Step>
                            <StepContentParent>
                                <StepContent>
                                    <Title>myTitle2</Title>
                                    <Details>myDetails2</Details>
                                </StepContent>
                            </StepContentParent>
                            <Steps><!--Could be empty or could be the same as the previous Steps (recursion ) -->
                                <Step><!--want to process all of them-->
                                    <StepContentParent>
                                        <StepContent>
                                            <Title>myTitle2.1</Title>
                                            <Details>myDetails2.1</Details>
                                        </StepContent>
                                    </StepContentParent>
                                    <Steps/><!--Could be empty or could be the same as the previous Steps (recursion ) -->
                                    <SubDoc><!-- could be empty -->
                                        <SubDocInstance>
                                            <DocInstance>
                                                <MainDoc/><!-- Same as Root (recursion ) -->
                                            </DocInstance>
                                        </SubDocInstance>
                                    </SubDoc>
                                </Step>
                                <step/>
                                <step/>
                            </Steps>
                        </Step>
                        <step/>
                        <step/>
                    </Steps>
                </Build>
            </BuildList>
        </Content>
    </ContentList>
</MainDoc>

Answer 1

由于使用带有apply-templates的身份转换具有“内置递归”，我不确定问题是什么，您只需将其用作起点（例如，在 XSLT 3 中使用<xsl:mode on-no-match="shallow-copy"/> )，然后添加与要删除的元素匹配的空模板和/或与要重命名或转换的元素匹配的模板：

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:xs="http://www.w3.org/2001/XMLSchema"
    exclude-result-prefixes="#all"
    version="3.0">

  <xsl:mode on-no-match="shallow-copy"/>

  <xsl:template match="MainDoc/MetaData/Date"/>

  <xsl:template match="StepContentParent/StepContent/Date"/>

  <xsl:template match="ContentList/Content[not(position() = last())]"/>

</xsl:stylesheet>

https://xsltfiddle.liberty-development.net/6pS26my