Re: [sca-c-cpp] NEW ISSUE: C++ mapping of multi-valued parameters

[Andrew Borley <BORLEY@uk.ibm.com>]

This issue has been assigned ID CCPP-106
by the jira system.
See http://www.osoa.org/jira/browse/CCPP-106

Andrew

____________________________________________________________

Andrew Borley
Websphere ESB Development
Tel: 245393 Ext: +44 (0) 1962 815393 Mob: +44 (0) 7971 805547
E-mail: borley@uk.ibm.com
Mailpoint 211, IBM (UK) Ltd, Hursley Park, Winchester, Hants, SO21 2JN
____________________________________________________________

From:	Bryan Aupperle <aupperle@us.ibm.com>
To:	sca-c-cpp@lists.oasis-open.org
Date:	11/03/2010 18:40
Subject:	[sca-c-cpp] NEW ISSUE: C++ mapping of multi-valued parameters

---

Target C++ C&I Spec (CD 05) 

Description: Section 9.3 defines the data mapping between C++ and WSDL/XML.
 The mapping is defined for simple types and complex types
but there is no definition for multi-value
elements (C++ arrays, list, vectors etc. and XML elements with maxOccurs
> 1).  If the XML element is contained in a complex type, but not
directly mapped to a function parameter/return type, the normal SDO mapping
rules apply, the resulting property has isMany=true.  However, if
the element is defining a function parameter/return type, there is no containing
DataObject. and the mapping is not defined.

For example: 
<wsdl:definitions
name="Service4Service"
        targetNamespace="http://test.sca.oasisopen.org/"
xmlns:tns="http://test.sca.oasisopen.org/"
        xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
        xmlns:SOAP="http://schemas.xmlsoap.org/wsdl/soap/"
xmlns:SOAP11="http://schemas.xmlsoap.org/wsdl/soap/">
        <wsdl:types>
                <xs:schema
attributeFormDefault="qualified"
                    
   elementFormDefault="unqualified"
targetNamespace="http://test.sca.oasisopen.org/"
                    
   xmlns:xs="http://www.w3.org/2001/XMLSchema">
                    
   <xs:import
/>
                    
   <xs:element
name="operation1Response">
                    
           <xs:complexType>
                    
                   <xs:sequence>
                    
                     
     <xs:element
minOccurs="0"
name="return"
nillable="true"
                    
                     
             type="xs:string"
/>
                    
                   </xs:sequence>
                    
           </xs:complexType>
                    
   </xs:element>
                    
   <xs:element
name="operation1">
                    
           <xs:complexType>
                    
               <xs:sequence>
                    
   <xs:element
name="arg0"
type="xs:string"
minOccurs="0"
maxOccurs="unbounded"/>
                    </xs:sequence>
                    
           </xs:complexType>
                    
   </xs:element>
                </xs:schema>
        </wsdl:types>
        <wsdl:message
name="operation1Response">
                <wsdl:part
name="operation1Response"
element="tns:operation1Response">
                </wsdl:part>
        </wsdl:message>
        <wsdl:message
name="operation1">
                <wsdl:part
name="operation1"
element="tns:operation1">
                </wsdl:part>
        </wsdl:message>
        <wsdl:portType
name="Service4">
                <wsdl:operation
name="operation1">
                    
   <wsdl:input
message="tns:operation1">
                    
   </wsdl:input>
                    
   <wsdl:output
message="tns:operation1Response">
                    
   </wsdl:output>
                </wsdl:operation>
        </wsdl:portType>
</wsdl:definitions>
The element arg0 in the global element operation1 defines a single input
parameter to operation1, but this element has maxOccurs=unbounded. so the
type of the parameter needs to allow multiple values.  Mapping this
to a DataObject would result in unnecessary overhead, more complicated
client and implementation code and a lack of clarity as to the name of
the property in the DataObject actually containing the data.

Proposal: 
Direction 
When mapping from C++ to WSDL/XML map parameters/return types with a type
that is an array, or a list, vector (probably double ended queue and its
variations - queue, stack and priority queue - as well) to an XML element
with maxOccurs=unbounded. 
When mapping from WSDL/XML to C++ map elements with maxOccurs > 1 that
define parameters/return types to a list<type> where type is either
the simple type of the element or DataObjectPtr>

Bryan Aupperle, Ph.D.
STSM, WebSphere Enterprise Platform Software Solution Architect

Research Triangle Park,  NC 
+1 919-254-7508 (T/L 444-7508)
Internet Address: aupperle@us.ibm.com

---

Unless stated otherwise above:
IBM United Kingdom Limited - Registered in England and Wales with number 741598.
Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU