Re: [wsbpel] Issue - 87 - Proposal for Vote - Part 1

[Francisco Curbera <curbera@us.ibm.com>]

Yaron,

There is the problem of several headers (or "application data" units as you
call them) being typed by the same WSDL message type. I don't recall any
limitation as to the uniqueness of the message type used to type a header.
Since WSDL does not let you identify a "message type instance" except when
used for input and output of the WSDL operation the problem you try to
address seems inherently ambiguous to me. Moreover, I don't think there is
an easy solution to this problem that does not involve fixing WSDL 1.1 in
one way or another.

While I understand (but not share, as we have discussed in the past) your
concern for bringing this issue up, I am very uneasy about using BPEL to
make up for the shortcomings of other specifications.

Paco



                                                                                                                                  
                      "Yaron Y. Goland"                                                                                           
                      <ygoland@bea.com>        To:       wsbpeltc <wsbpel@lists.oasis-open.org>                                   
                                               cc:                                                                                
                      09/28/2004 02:35         Subject:  [wsbpel] Issue - 87 - Proposal for Vote - Part 1                         
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                      ygoland                                                                                                     
                                                                                                                                  




The original proposal for vote contained two parts, one that defined the
generic mechanism and another that specified language for specific
bindings. In order to allow us to make forward progress I am removing
the section on specific bindings for this vote and instead just focusing
on the mechanism. This vote will not close issue 87 as, if it is passed,
we will still need to decide if we wish to address any binding specific
issues.

14.9 Application Data

Application data is data transmitted in a message outside
of the normal message channel, specifically data in a message that is
not bound to a WSDL message part referenced in the portType/operation
definition that applies to the sent or received message.

To enable BPEL processes to access application data the from-spec is
extended to include:

<from appDataForMessage="ncname"/>

The value of the appDataForMessage attribute MUST be the name of a WSDL
message type variable. The output of this from-spec will always follow
the schema:

<element name="applicationData" type="bpws:tApplicationData">

<complexType name="tApplicationData">
     <sequence>
        <any processContents="lax" minOccurs="0" maxOccurs="unbounded"/>
     </sequence>
     <anyAttribute processContents="lax"/>
</complexType>

The application data will be recorded inside of the applicationData XML
element.

To enable BPEL processes to set application data the to-spec is extended
to include:

<to appDataForMessage="ncname"/>

The schema of the data assigned using this to-spec MUST follow the
previously defined schema or a bpws:mismatchedAssignmentFailure MUST be
thrown.

When a message is received by the BPEL process any application data
associated with the message MUST be made available via the application
data from-spec. The exact means by which application data is retrieved
from a message is binding specific and the binding definition has final
say as to what data will appear as application data but in general any
parts of the incoming message that do not have bindings to specific WSDL
message parts are considered application data. Similarly when a message
is sent if any application data has been associated with the message
then the application data MUST be sent with the outgoing message using
the rules defined for the particular binding in use.

Any application data associated with a WSDL message type variable is
replaced with application data from the incoming message, if any,
whenever that variable is used to receive a new message.

Schema Changes:

Add to tFrom:

<attribute name="appDataForMessage" type="NCName"/>

Add to to:

<attribute name="appDataForMessage" type="NCName"/>

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