XSLT foreach repeating nodes to flat

问题:

I have an XML schema that I need to extract values from but I am not having much luck.

The souce schema is:

<Reading>
   <State>
      <StateValues>
         <Name>
         <Value>
      </StateValues>
   </State>
<Reading>

An example of the XML would be:

<Reading>
   <State>
      <StateValues>
         <Name>Reading1</Name>
         <Value>1234</Value>
      </StateValues>
      <StateValues>
         <Name>Reading2</Name>
         <Value>2345</Value>
      </StateValues>
   </State>
   <State>
      <StateValues>
         <Name>Reading3</Name>
         <Value>4321</Value>
      </StateValues>
   </State>
<Reading>

I need a result that is:

<Readings>
  <Reading1>1234</Reading1>
  <Reading2>2345</Reading2>
  <Reading3>4321</Reading3>
</Readings>

I have no control over the schemas.

I have been trying to use a xsl:foreach with an xsl:if that checks the name but I just get the first value repeated 3 times. Any tips? I've been trying to figure this out for 2 days and I am not an XSLT expert...

Thanks. EDIT : Sorry for not posting my XSLT. I had tried several versions and didn't think it would be useful. Here it is:

Blockquote

<xsl:element name="ns0:Readings">
   <xsl:element name="ns0:Current">
         <xsl:for-each select="/*[local-name()='gatewayInterface' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='Reading' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='State' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='StateValues' and namespace-uri()='http://biztalk.gateway.com']">               
            <xsl:choose>
               <xsl:when test="Name='TOTAL'">
            <xsl:element name="ns0:Total">
                <xsl:value-of select="/*[local-name()='gatewayInterface' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='Reading' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='State' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='StateValues' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='Name' and namespace-uri()='http://biztalk.gateway.com']/text()='Total'" />
            </xsl:element>
           </xsl:when>
        </xsl:choose>
        <xsl:choose>
           <xsl:when test="/*[local-name()='gatewayInterface' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='Reading' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='State' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='StateValues' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='Name' and namespace-uri()='http://biztalk.gateway.com']/text()='Reading1'">
        <xsl:element name="ns0:Reading1">
            <xsl:value-of select="/*[local-name()='gatewayInterface' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='Reading' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='State' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='StateValues' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='Name' and namespace-uri()='http://biztalk.gateway.com']/text()" />
            </xsl:element>
           </xsl:when>
        </xsl:choose>
        <xsl:choose>
           <xsl:when test="/*[local-name()='gatewayInterface' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='Reading' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='State' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='StateValues' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='Name' and namespace-uri()='http://biztalk.gateway.com']/text() = 'Reading2'">
        <xsl:element name="ns0:Reading2">
            <xsl:value-of select="/*[local-name()='gatewayInterface' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='Reading' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='State' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='StateValues' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='Name' and namespace-uri()='http://biztalk.gateway.com']/text()" />
            </xsl:element>
           </xsl:when>
        </xsl:choose>
        <xsl:choose>
           <xsl:when test="/*[local-name()='gatewayInterface' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='Reading' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='State' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='StateValues' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='Name' and namespace-uri()='http://biztalk.gateway.com']/text() = 'Reading3'">
        <xsl:element name="ns0:Reading3">
            <xsl:value-of select="/*[local-name()='gatewayInterface' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='Reading' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='State' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='StateValues' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='Name' and namespace-uri()='http://biztalk.gateway.com']/text()" />
            </xsl:element>
           </xsl:when>
        </xsl:choose>
        <xsl:choose>
           <xsl:when test="/*[local-name()='gatewayInterface' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='Reading' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='State' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='StateValues' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='Name' and namespace-uri()='http://biztalk.gateway.com']/text() = 'Reading4'">
        <xsl:element name="ns0:Reading4">
            <xsl:value-of select="/*[local-name()='gatewayInterface' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='Reading' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='State' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='StateValues' and namespace-uri()='http://biztalk.gateway.com']/*[local-name()='Name' and namespace-uri()='http://biztalk.gateway.com']/text()" />
            </xsl:element>
           </xsl:when>
        </xsl:choose>
     </xsl:for-each>
   </xsl:element>
</xsl:element>

回答1:

foreach and if are usually the wrong approach in XSLT. It is far more effective to apply templates to patterns. In this case you can use two: the first sets up the root element and matches the elements you want to work with:

<xsl:template match='/'>
  <Readings>
    <xsl:apply-templates select='Reading/State/StateValues'/>
  </Readings>
</xsl:template>

and a second that the above triggers when a match is found that will do the core work. The complexity here is creating an element dynamically which means using the {XPath} syntax to get the name from the input document:

<xsl:template match='StateValues'>
  <xsl:element name='{Name}'>
    <xsl:value-of select='Value' />
  </xsl:element>
</xsl:template>