[英]How to merge (with overwrite) two xml documents?
Suppose I have an A document like this: 假设我有一个这样的A文档:
<document>
<element>
<value>1</value>
<wom>bat</wom>
</element>
<bar>
<baz />
<baz />
<baz />
</bar>
</document>
and a B document like this: 和这样的B文档:
<document>
<element>
<value>2</value>
</element>
<bar>
</bar>
</document>
With the result which looks like this: 结果如下:
<document>
<element>
<value>2</value>
<wom>bat</wom>
</element>
<bar>
</bar>
</document>
So what I'd like to achieve is to overwrite values in a tag (like in element
) in document A with values provided from document B but leave the sibling values untouched. 因此,我想要实现的是使用文档B中提供的值覆盖文档A中标签中的值(如element
中的值),而兄弟值保持不变。 If the tag in B however is empty (leaf) I want its counterpart in A to be emptied as well. 如果B中的标签是空的(叶子),我也希望将A中的标签也清空。 I've checked this question but it is merging not overwriting. 我检查了这个问题,但它不是合并而已。 How can I solve this problem? 我怎么解决这个问题?
Clarification: A and B documents have the same structure but B has less elements. 说明性: A和B文档具有相同的结构,但是B的元素较少。 I have to empty every element in A which is empty in B and I have to overwrite every inner element in an element if it is not empty (see my example). 我必须清空A中的每个元素,而B中为空,并且如果它不为空,则必须覆盖元素中的每个内部元素(请参见我的示例)。
One approach could be to navigate over DocumentA, but passing in a parameter set to the equivalent node in Document B. 一种方法是在DocumentA上导航,但将参数集传递给Document B中的等效节点。
To start with, match the document node of A, and start the matching off with the document node from B 首先,匹配A的文档节点,然后从B的文档节点开始匹配
<xsl:template match="/">
<xsl:apply-templates>
<xsl:with-param name="parentB" select="document('DocB.xml')"/>
</xsl:apply-templates>
</xsl:template>
Then, you would have a template matching any element (in A) with the current (parent) node in B as the parameter 然后,您将拥有一个模板,该模板将A中的任何元素与B中的当前(父)节点作为参数匹配
<xsl:template match="*">
<xsl:param name="parentB"/>
To find the equivalent 'child' node in B, you would first find the current position of the A node (should there be more than one child of the same name), and then check if such a child exists under the parent B node 要在B中找到等效的“子”节点,您首先要找到A节点的当前位置(如果有多个同名子节点),然后检查在父B节点下是否存在这样的子节点
<xsl:variable name="posA">
<xsl:number />
</xsl:variable>
<xsl:variable name="nodeB" select="$parentB/*[local-name() = local-name(current())][number($posA)]"/>
Then, it is just a case of determining whether to copy the A or B node. 然后,仅是确定是否复制A或B节点的情况。 To copy the B node, the B node would have to exist, and not have any child elements (it might have child text nodes though, which would be copied 要复制B节点,B节点必须存在,并且不具有任何子元素(尽管它可能具有子文本节点,但将被复制)
<xsl:when test="$nodeB and not($nodeB/*)">
<xsl:copy-of select="$nodeB/node()"/>
</xsl:when>
Otherwise, continue processing the A node (passing in the current B node as a parameter). 否则,继续处理A节点(将当前B节点作为参数传递)。
Try this XSLT 试试这个XSLT
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="xml" indent="yes"/>
<xsl:template match="/">
<xsl:apply-templates>
<xsl:with-param name="parentB" select="document('DocB.xml')"/>
</xsl:apply-templates>
</xsl:template>
<xsl:template match="*">
<xsl:param name="parentB"/>
<xsl:variable name="posA">
<xsl:number />
</xsl:variable>
<xsl:variable name="nodeB" select="$parentB/*[local-name() = local-name(current())][number($posA)]"/>
<xsl:copy>
<xsl:choose>
<xsl:when test="$nodeB and not($nodeB/*)">
<xsl:copy-of select="$nodeB/node()"/>
</xsl:when>
<xsl:otherwise>
<xsl:apply-templates select="@*|node()">
<xsl:with-param name="parentB" select="$nodeB"/>
</xsl:apply-templates>
</xsl:otherwise>
</xsl:choose>
</xsl:copy>
</xsl:template>
<xsl:template match="@*|node()[not(self::*)]">
<xsl:copy>
<xsl:apply-templates select="@*|node()"/>
</xsl:copy>
</xsl:template>
</xsl:stylesheet>
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