connect data from different elements of xml file while making xml to xml transformation with xslt-CodePudding

So, I have xml file with structure:

`<root>
    <messages>
        <message id="1005">
            <title>message1</title>
            <text>text1</text1>
        </message>
        <message id="1012">
            <title>message2</title>
            <text>text2</text1>
        </message>
        <message id="13001">
            <title>message3</title>
            <text>text3</text1>
        </message>  
    </messages>
    <data>
        <sender>
            <name>sender1</name>
            <messages>
                <message id="1005" time="12:00"/>
                <message id="1012" time="12:30"/>
            </messages>
        </sender>
        <sender>
            <name>sender2</name>
            <messages>
                <message id="10012" time="2:00"/>
                <message id="13001" time="13:20"/>
            </messages>
        </sender>
    </data>
<root>`

Output I need for each message:

`<Record>
    <Message>
        <MessageID>1005</MessageID>
        <MessageTitle>message1</MessageTitle>
        <time>12:00</time>
        <sender>sender1</sender>
    </message>
</Record>`

I understand what needs to be done to output the id and title from the source file. Problem is I don't know how to make this kind of sql join connection to output time and sender from another element.

CodePudding user response：

Here's a simple way this could be done using a key.

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    version="1.0">
  
  <xsl:output method="xml" indent="yes"/>
  
  <xsl:key name="message_key" match="message[ancestor::data]" use="@id"/>

  <xsl:template match="/">
    <Records>
      <xsl:apply-templates select="root/messages/message"/>
    </Records>
  </xsl:template>
  
  <xsl:template match="message">
    <Record>
      <Message>
        <MessageID><xsl:value-of select="@id"/></MessageID>
        <MessageTitle><xsl:value-of select="title"/></MessageTitle>
        <time><xsl:value-of select="key('message_key',@id)/@time"/></time>
        <sender><xsl:value-of select="key('message_key',@id)/../../name"/></sender>
      </Message>
    </Record>
  </xsl:template>
  
</xsl:stylesheet>

See it working here: https://xsltfiddle.liberty-development.net/3NqjwkK