This differs from the previous information in this chapter because there is a difference in how XPath queries are constructed for the two WSDL message styles. For an RPC-style message, the top-level element (and therefore the first node in an XPath query string) is the part name (payload in the previous example). In document-style messages, the top-level node is the element name (for example, loanApplication).

The following examples (WSDL file and BPEL file) show what an XPath query string looks like if an application named LoanServices were in RPC style.

<message name="LoanServiceResultMessage">
   <part name="payload" type="s1:LoanOfferType"/>
</message>

<complexType name="LoanOfferType">
   <sequence>
      <element name="providerName" type="string"/>
      <element name="selected" type="boolean"/>
      <element name="approved" type="boolean"/>
      <element name="APR" type="double"/>
   </sequence>
</complexType>

<variable name="output"
          messageType="tns:LoanServiceResultMessage"/>
...
<assign>
   <copy>
      <from expression="9.9"/>
      <to variable="output" part="payload" query="/payload/APR"/>
   </copy>
</assign>