Re: [xsl] Can a streaming loop be inside a non-streaming loop?

["Martin Honnen martin.honnen@xxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

On 08/08/2025 13:27, Roger L Costello costello@xxxxxxxxx wrote:
> Hi Folks,
>
> I have an XML document, idents.xml, that contains a list of identifiers. For
each identifier, I want to loop--in a streaming fashion--over all the records
in a huge file (records.xml). Here's what I've tried:
>
> <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:output method="xml" />
>
>      <xsl:variable name="identifiers" select="doc('idents.xml')/*"/>
>
>      <xsl:template name="main">
>          <xsl:source-document href="records.xml"
>                                                  streamable="yes">
>              <results>
>                  <xsl:variable name="records" select="/*"/>
>                  <xsl:for-each select="$identifiers/identifier">
>                      <xsl:variable name="ident" select="."/>
>                      <xsl:for-each select="$records/record">
>                          <xsl:variable name="record" select="copy-of(.)"/>
>                          ...  (use $ident to process $record)
>                      </xsl:for-each>
>                  </xsl:for-each>
>              </results>
>          </xsl:source-document>
>      </xsl:template>
>
> </xsl:stylesheet>
>
> Running the above XSLT results in the following error message:
>
> XTSE3430  The body of the xsl:source-document instruction is not streamable
>    *  Operand {records} of {let $records := ...} selects streamed nodes in a
context that
>    allows arbitrary navigation
>
> What is the correct way to do this?
>
Can't you just stream through, materialize each "record" and then
process each repeatedly with the identifier list?

<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:output method="xml" />

     <xsl:variable name="identifiers" select="doc('idents.xml')/*"/>

     <xsl:template name="main">
         <xsl:source-document href="records.xml"
                                                 streamable="yes">
             <results>

                     <xsl:for-each select="records/record">
                         <xsl:variable name="record" select="copy-of(.)"/>
                         <xsl:for-each select="$identifiers/identifier">
                            <xsl:variable name="ident" select="."/>
                            ...  (use $ident to process $record)
                         </xsl:for-each>
                     </xsl:for-each>
                 </xsl:for-each>
             </results>
         </xsl:source-document>
     </xsl:template>

</xsl:stylesheet>