----- Original Message -----
Sent: Monday,
January 17, 2005 6:15 PM
Subject: RE:
[ciq] RE: CIQ XML Schema Issue &
Resolution
Hi
Stephen
I’ve encountered
this problem a few times in the past while implementing not only CIQ, but
some other standards as well.
Normally strong
typing is best left to the implementation. You’ll always need to tweak the
schema a little bit to fit your requirements, be it the Java binding library
you’re using, various flavours of parsers etc.
I, for example, had
to combine all CIQ schemas into one in order to implement it in webMethods!
Perhaps it would be
interesting to have versions of CIQ schemas ready for implementation for
different platforms/libraries (eg .NET, XMLBeans, webMethods, whatnot).
Having said this, I would be hesitant of putting any of these implementation
specifics into the standard itself. This is the main reason why there are no
strong-typed elements in the standard itself so
far.
As far as upgrading
to future versions of the standards, there always changes you will have to
implement anyway. If you stick to a consistent data typing approach, you’ll
minimise your migration headaches.
This is definitely
not a purist approach, but a practical and pragmatic one borne out of
necessity in dealing with lots of different tools and libraries out there.
I hope my comment
is helpful.
Regards,
--
Hido
Hasimbegovic
eBusiness Consultant | CustomWare Asia Pacific | www.customware.net
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From: Ram
Kumar [mailto:RKumar@msi.com.au]
Sent: Tuesday, 18 January 2005 9:35
AM
To: Viens,
Stephen
Cc:
ciq@lists.oasis-open.org
Subject: [ciq] RE: CIQ XML Schema Issue
& Resolution
Thank you for your detailed
email.
Yes, this is a problem with V2.0
and it is already in our
list of things to do. The future
versions of CIQ will be strongly data typed.
From:
Viens, Stephen [mailto:Stephen.Viens@LibertyMutual.com]
Sent: Tue 1/18/2005 9:33 AM
To: Ram Kumar
Subject: FW: CIQ XML Schema Issue &
Resolution
[Please forgive the
length of this message. I do believe you'll find the subject of
interest]
Ram, CIQ TC,
We're leveraging
the current CIQ standard schema's to implement a web service for managing
client data. We've included the CIQ schemas in the WSDL for our
service to describe the data managed by the service. We're using the
"WSDL First" method of web service development which recommends developing
the service's WSDL first and generating service and client code
(Java, C#, C++, etc) from that using common WSDL2Java code generation
tools.
Unfortunately we've
encountered a problem when trying to generate Java code from the CIQ
schemas. We're using two industry standard WSDL2Java generation tools
- Apache Axis 1.1 and IBM WSAD 5.1 - and we've been presented with the same
problem with both. The purpose of this note is to inform you of the
problem and describe how we've worked around
it.
When type
information for an elements character data is not specified the code
generation tools will produce a Java class without a class variable to
contain character data. In other words, the Java generation tools
assume that if type information isn't supplied for an element's character
data then it must be an "attributes only" element. Here's an
example:
<xs:element name="CustomerID" minOccurs="0"
maxOccurs="unbounded">
<xs:complexType mixed="true">
<xs:attribute name="Type"/>
<xs:attributeGroup ref="grPostal"/>
<xs:anyAttribute namespace="##other"/>
</xs:complexType>
</xs:element>
Here's the Java
code generated from the schema snippet above . You'll note that there is no
class variable to hold a CustomerID value - only the "Type" attribute is
represented.
public class CustomerID
{
private java.lang.Object type;
public CustomerID() {
}
public java.lang.Object getType() {
return type;
}
public void setType(java.lang.Object type) {
this.type = type;
}
}
Only when a
simpleContent element is specified with type information for the element's
character data (xs:string) will the generation tools produce Java that
includes a class variable and getter/setter methods for a CustomerID
value. Below is an example. This is the same schema snippet
shown above with the addition of the "xs:simpleContent" and "xs:extension"
elements:
<xs:element name="CustomerID" minOccurs="0"
maxOccurs="unbounded">
<xs:complexType mixed="true">
<xs:simpleContent>
<xs:extension
base="xs:string">
<xs:attribute name="Type"/>
<xs:attributeGroup ref="grPostal"/>
<xs:anyAttribute namespace="##other"/>
</xs:extension>
</xs:simpleContent>
</xs:complexType>
</xs:element>
Here is the Java
code that is generated from the modified schema. You'll notice that a class
variable for the CustomerID value is now present as well as getValue and
setValue methods:
public class CustomerID
{
private
java.lang.String value;
private java.lang.Object type;
public CustomerID() {
}
public java.lang.String getValue() {
return value;
}
public void setValue(java.lang.String value) {
this.value = value;
}
public java.lang.Object getType() {
return type;
}
public void setType(java.lang.Object type) {
this.type = type;
}
}
The way the
WSDL2Java tools work makes sense in a way. How else would they be able
to know if an element includes (or does not include) character data without
it being explicitly stated in the schema?
Would the CIQ team
consider updating the schemas to include these changes or at least
incorporating these changes into future
versions?
We have been forced
to make many alterations to the CIQ schemas for our web service to leverage
them. We're concerned that we will have to make all of the same
alterations when (if) we decide to upgrade to a new version of CIQ in the
future.
Steve
Stephen
Viens
Enterprise
Architect
Liberty Mutual
Insurance Company
Enterprise IT Services
(EITS)
stephen.viens@libertymutual.com
603-245-3467
(phone)
603-245-5338
(fax)