Unable to parse a xml field value from a variable as document version using document-version-uri function in MarkLogic

Question

I am trying the below xquery to add the field value from the xml field - SystemRef which is set in the variable root.

I wanted to see the version of the document as - EDI_22000043.xml_2022-11-29T13:59:00.739688Z But I am getting the result as this - EDI_.xml_2022-11-29T14:10:28.466401Z

Xquery :

xquery version "1.0-ml";
import module namespace temporal = "http://marklogic.com/xdmp/temporal" 
    at "/MarkLogic/temporal.xqy";   
let $root := 
<EDILogFile>
    <ID>f1258d4ae0df43d5a1e05ce9139f0ed2</ID>
    <SystemRef>22000043</SystemRef>
  <system-Start>(fn:current-time())</system-Start>
  <system-End></system-End>
  <DateCreated>2022-09-09T19:07:46.3492849+01:00</DateCreated>
    <TimeSaved>240</TimeSaved>
    <Production>true</Production>
    <Partner>Ellerman</Partner>
    <MessageType>Invoice</MessageType>
    <Fail>true</Fail>
    <ManyReasons/>
    <SubmissionUser>System</SubmissionUser>
    <InternalBusinessUnit>Finance</InternalBusinessUnit>
    <Direction>Inbound</Direction>
</EDILogFile>
return (
temporal:statement-set-document-version-uri("EDI_22000043.xml",(fn:concat("EDI","_",$root/EDILogFile/SystemRef/text(),".","xml","_",fn:current-dateTime()))),
temporal:document-insert("UnitemporalColl-SysAxesInDoc", "EDI_22000043.xml", $root)
)

Answer 1

Your $root variable is the EDILogFile element, not a document. So, the context for an XPath is starting from the EDILogFile element (you are "standing on" that element and it's immediate child is SystemRef.

If you select a document from the database you are "standing" on the document-node() and it's immediate child node would be the EDILogFile element, and that XPath would work as expected. However, since you have let a local variable that is just an Element you need to make an adjustment.

You should use the XPath: $root/SystemRef/text() instead of $root/EDILogFile/SystemRef/text().