XPATH expression to get Array node

Question

Hi
I have a problem with an XPATH expression in BPEL. I want to get to a particular node in the following result set ..
<return xmlns:ns2="http://schemas.xmlsoap.org/soap/encoding/" xmlns:ns3="http://com.quion.taken.services/ITakenService.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="ns2:Array" ns2:arrayType="ns3:com_quion_dto_taken_BouwnotaVoorraadDTO[2]">
<item xsi:type="ns3:com_quion_dto_taken_BouwnotaVoorraadDTO">
<begunstigde xsi:type="xsd:string">Sjoerd</begunstigde>
<datum xsi:type="xsd:dateTime">2005-10-31T23:00:00.000Z</datum>
<bedrag xsi:type="xsd:string">1000.0</bedrag>
<geldLeningId xsi:type="xsd:string">4.0</geldLeningId>
<rekeningnummer xsi:type="xsd:string">1234</rekeningnummer>
<notaId xsi:type="xsd:string">1.0</notaId>
</item>
<item xsi:type="ns3:com_quion_dto_taken_BouwnotaVoorraadDTO">
<begunstigde xsi:type="xsd:string">Laszlo</begunstigde>
<datum xsi:type="xsd:dateTime">2005-10-31T23:00:00.000Z</datum>
<bedrag xsi:type="xsd:string">1.0</bedrag>
<geldLeningId xsi:type="xsd:string">4.0</geldLeningId>
<rekeningnummer xsi:type="xsd:string">5678</rekeningnummer>
<notaId xsi:type="xsd:string">2.0</notaId>
</item>
</return>
The first thing is that my variable in BPEL does not show the ïtem"level", it shows for example 'return/notaId'.
However I can get to the second node by keying in
EXPRESSION 1:
bpws:getVariableData('invokeGetBouwnotaVoorraadVoorLening_getBouwnotaVoorraadVoorLening_OutputVariable','return','/return/item[1]/notaId')
No I want to dynamically determine the particular node instance. I do this as follows [copied from the Array sample]:
EXPRESSION 2:
bpws:getVariableData('invokeGetBouwnotaVoorraadVoorLening_getBouwnotaVoorraadVoorLening_OutputVariable','return','/return/item[', bpws:getVariableData('i'),']/notaId')
BPEL throws the following error
assignNotaId (faulted)
[2005/11/09 09:49:36] Updated variable "invokeTaskManager_initiateTask_InputVariable" More...
<invokeTaskManager_initiateTask_InputVariable>
<part xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" name="payload">
<task xmlns="http://services.oracle.com/bpel/task">
<taskId />
<title />
<creationDate />
<creator />
<modifyDate />
<modifier />
<assignee>jstein</assignee>
<status />
<expired />
<expirationDate />
<duration />
<priority />
<template />
<customKey />
<conclusion />
<attachment />
</task>
</part>
</invokeTaskManager_initiateTask_InputVariable>
[2005/11/09 09:49:36] Error in evaluate <from> expression at line "172". The result is empty for the XPath expression : "bpws:getVariableData('invokeGetBouwnotaVoorraadVoorLening_getBouwnotaVoorraadVoorLening_OutputVariable','return','/return/item[', bpws:getVariableData('i'),']/notaId')".
[2005/11/09 09:49:36] "{http://schemas.xmlsoap.org/ws/2003/03/business-process/}selectionFailure" has been thrown. less
<selectionFailure xmlns="http://schemas.xmlsoap.org/ws/2003/03/business-process/">
<part name="summary">
<summary>empty variable/expression result. xpath variable/expression expression "bpws:getVariableData('invokeGetBouwnotaVoorraadVoorLening_getBouwnotaVoorraadVoorLening_OutputVariable','return','/return/item[', bpws:getVariableData('i'),']/notaId')" is empty at line 172, when attempting reading/copying it. Please make sure the variable/expression result "bpws:getVariableData('invokeGetBouwnotaVoorraadVoorLening_getBouwnotaVoorraadVoorLening_OutputVariable','return','/return/item[', bpws:getVariableData('i'),']/notaId')" is not empty.</summary>
What is wrong with my expression 2?
Thanks
Jan Willem

Answer 1

This Example works fine for arrays that are part of a WSDL message.
But in 10.1.3.1 this does not work with a array that is part of an XSD declaration
for Example XSD snippet
<xsd:element name="itemList">
          <xsd:complexType>
               <xsd:sequence>
                    <xsd:element maxOccurs="unbounded" minOccurs="1" ref="tns:Item" />
               </xsd:sequence>
          </xsd:complexType>
     </xsd:element>
using the following in assign statement
<copy>
<from expression="concat('/ns9:itemList/ns9:Item[',string(bpws:getVariableData('index')),']')"/>
<to variable="idxXpath"/>
</copy>
<copy>
<from expression="bpws:getVariableData('OutputItemList',bpws:getVariableData('idxXpath'))"/>
<to variable="idx_item"/>
</copy>
gives a compiler error that is
Error(176):
[Error ORABPEL-10085]: invalid argument
[Description]: in line 176 of "D:\OnlineShopping_1\bpel\OnlineShopping.bpel", the second argument "bpws:getVariableData("idxXpath")" for getVariableData is not a literal expression.
[Potential fix]: Please correct the second argument, you might need to escape using single quote or " to make it literal.
Can anyone site the reason for the same or a possible solution?
Message was edited by:
user607972