The JAX-RPC spec prohibits use of attributes as content of the wrapper
element, but it says nothing regarding attributes as content of the elements
which are children of the wrapper element. Many other implementations
support attributes as content of the child elements.
So this is prohibited:
<element name="wrapper">
<complexType>
<sequence>
<element name="foo" type="string"/>
</sequence>
<attribute name="bar" type="string"/>
</complexType>
</element>
But this should be okay:
<element name="wrapper">
<complexType>
<sequence>
<element name="foo" type="string"/>
<element name="bar" type="tns:bar"/>
</sequence>
</complexType>
</element>
<complexType name="bar">
<sequence>
<element name="bat" type="string"/>
</sequence>
<attribute name="baz" type="string"/>
</complexType>
Unfortunately, the WS-I Basic Profile doesn't talk about wrapped versus
document style, so there's no definitive source of enlightenment for the
correct way to implement wrapped style. Axis document style supports
interoperability with .NET wrapped style when using attributes, so I don't
view this as a serious problem, although obviously lack of support for
attributes in the wrapper element reduces the ease of use of Axis.
Given that code generated by a wsdl2java tool is always dependent on the
associated SOAP engine, I don't see a breach of JAX-RPC compliance in this
small area as a particularly bad thing. I think more seamless
interoperability with .NET is always desirable. But I suspect that others
might feel differently.
I also suggest that folks submit feedback to the JAX-RPC Expert Group and
request support for attributes in wrapped style in JAX-RPC 2.0.
Anne
-----Original Message-----
From: Liu, Scott [mailto:[EMAIL PROTECTED]
Sent: Monday, September 13, 2004 1:59 PM
To: [EMAIL PROTECTED]
Subject: RE: The Attributes and the UN-"wrapper" style
Not that Axis does not support attributes at all it does support it in
general. It just does not support it for the "wrapper element", which is
not really wrong since JAX-RPC spec specifies so. I could "fix" Axis to
support it for this element which would be against the spec. I would
like to know from our experts that why the JAX-RPC spec does not support
it even though it is a such easy thing to do.
I am also interested to know if Axis should support attributes on
"wrapper element" if we do not use the "wrapper" style since the JAX-RPC
does not mention anything on this.
I have read comments on the topic from Anne Thomas Manes
(http://www.burtongroup.com/weblogs/annethomasmanes/archives/cat_apache_
axis.html). It is very helpful in understanding encoding style and
programming style.
Thanks,
Scott
-----Original Message-----
From: Peter White [mailto:[EMAIL PROTECTED]
Sent: Monday, September 13, 2004 6:36 AM
To: [EMAIL PROTECTED]
Subject: RE: The Attributes and the UN-"wrapper" style
I have actually seen axis support document style (very close to wrapped)
attributes in version 1.0 RC1...
Here is a document-style encoded WSDL schema Snippet of a Email Add
element:
<xs:simpleType name="EmailKind">
<xs:restriction base="xs:string">
<xs:enumeration value="Home"/>
<xs:enumeration value="Work"/>
<xs:enumeration value="Mobile"/>
<xs:enumeration value="Other"/>
</xs:restriction>
</xs:simpleType>
<xs:complexType name="EmailAddType">
<xs:sequence>
<xs:element name="email"
type="xs:string"/>
</xs:sequence>
<xs:attribute name="emailKind"
use="required" type="m1:EmailKind"/>
</xs:complexType>
When run through WSDL2Java, I get a class called EmailAddType with
methods like getEmailKind and setEmailKind. The autogenerated
deserializer knows that emailKind is coming in as an attribute and that
email is coming in as a string. So when I make the request that has
<EmailAddType emailKind="Home"><email>[EMAIL PROTECTED]</email></EmailAddType>
in it... Axis will deserialize it into an EmailAddType object with a
stored email of "[EMAIL PROTECTED]" and an emailKind of "Home"
The tricky things I've found are: That if I had named the attribute
EmailKind instead of emailKind (and the email element Email)... The
deserializer would have blown up because it didn't match a jax-rpc
naming convention (lower case letters first in sub-elements of the
complex request). Also, simple types don't maintain minoccurs and
maxoccurs information. So <xs:element name="email" type="xs:string"
minOccurs="0"/> would not register with WSDL2Java, and when you deploy
your app to axis... It would show the WSDL without that minOccurs
attribute. You'd have to work aroun it by using an ArrayOfEmails
element and defining the limits there.
Either way, it seems Axis does have conventions for taking the
attributes and just sneaking them into the objects created with a little
"this is an attribute of this type, not part of the sequence" flag.
In Wrapped you specify which parts go with the method in the WSDL by
mapping the soap requests to the method invocations. (and in document,
you have to make sure not to have more than one soap binding - message
mapping with the same name, because the standard is less tightly bound)
EmailAddType is contained in ArrayOfEmailAdds.. Which is contained in
the CustomerAdd Element, which is what is used by the AddCustomerRequest
element, which is mapped to the AddCustomer SOAP service.
So yea, it sounds like you defintely want to stick with wrapped rather
than RPC because the schema used in wrapper will define attributes...
And I've actually seen wrapped attributes snuck into class objects by
axis so I think if you just try it you'll be pleasantly surprised (or
have you tried it and had it not work?), unless they removed the
functionality in 1.1/1.2.
-----Original Message-----
From: Jeff Greif [mailto:[EMAIL PROTECTED]
Sent: Friday, September 10, 2004 10:09 PM
To: [EMAIL PROTECTED]
Subject: Re: The Attributes and the UN-"wrapper" style
A speculation (I'm not an expert):
If you have
<wrapper someatt="somevalue">
<part1>...</part1>
<part2>...</part2>
</wrapper>
being converted to a method call on the server:
ServiceClass.someMethod(part1, part2) the attributes are lost.
There is no way in wsdl to specify "parts" which correspond to
attributes in wsdl.
As for using attributes in the non-wrapped implementation, in the wsdl,
you cannot tell whether a document style service will be implemented as
the wrapped form or the someMethod(wrapper) form, so the client would
not be able to tell whether the attributes would be lost in the server
or not. The implementation should be able to change transparently
between the two forms without affecting the abstract description or the
client.
Jeff
----- Original Message -----
From: "Liu, Scott" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Friday, September 10, 2004 4:31 PM
Subject: The Attributes and the UN-"wrapper" style
Hi, All,
There has been discussion about the "wrapper" style and the attributes
in the past. And Axis does not support wrapper element attributes since
JAX-RPC spec says that the wrapper element should not have attributes. I
have no problem with it. But I do like people to clarify the following
questions.
1. I know that it might be against the spec to have attributes for the
wrapper element. But it is such a simple change on Axis to support
attributes (I made minor change on client code generated with Axis tool
and it worked) I am wondering why the JAX-RPC insists that there is no
attributes for the wrapper element (.NET supports the attributes
anyway)? Does anyone know the story behind this?
2. I did not read the whole JAX-RPC spec and so what I said might be
wrong. Correct me if it is the case.
Since attributes are such a big part of xml schema and if I use the
attributes to go with the UN-wrapped style does Axis support it? My test
revealed that it did not with v1.1. Is there a patch or will it be
supported in Axis 1.2 for un-wrapped style?
Your explanation is highly appreciated,
Thanks,
Scott
