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RE: toRole and fromRole names and type references and similar.

From: Tony Fletcher <tony_fletcher@btopenworld.com>
Date: Mon, 21 Mar 2005 12:46:08 -0000
To: "'Gary Brown'" <gary@enigmatec.net>, <public-ws-chor@w3.org>
Message-ID: <000201c52e13$f5440860$6501a8c0@corp.choreology.com>
Dear Gary,
 
Thank you for your response.  The intent was not role instances but rather
instances of roleTypes - which is a role!
 
That is the point I am making.  At present we set up the participantType,
roleType and ChannelType definitions, but then each time we use a role we
have to give it a name and say what type it is.  If you look towards the
bottom of my mail you will see I have suggested adding a roleAssignments
element where one could say what roles the choreography used give them names
and say what type they were and then we could just use the role name and
omit the type reference elsewhere.

<roleAssignments name="ncname" ">

   <roleAssignment role name="ncname" roleType="qname" />+

</roleAssignments>

 
Maybe even better would be to have an element where one assigned a name to a
participant and said what type it was and gave names to each role in that
participant - we define participantTypes at present but never seem to use
participants (of a given type).
 
So we would then have:

<participantType name="ncname">

   <roleType typeRef="qname" />+

</participantType>

and something like

<participant name="ncname" typeRef="qname">

   <role name="ncname" typeRef="qname" />+

</participantType>

where the typeRef of the participant needs to match an 'ncname' of a
participantType and the typeRef (s) of the role(s) need to match the
corresponding 'ncname'(s) of a roleType contained in that participantType.
 
Best Regards     Tony
A M Fletcher
Home: 35, Wimborne Avenue, IPSWICH  IP3  8QW
Tel: +44 (0) 1473 729537   Mobile: +44 (0) 7801 948219
 amfletcher@iee.org       (also tony_fletcher@btopenworld.com)
 
-----Original Message-----
From: Gary Brown [mailto:gary@enigmatec.net] 
Sent: 21 March 2005 08:57
To: Tony Fletcher; public-ws-chor@w3.org
Subject: Re: toRole and fromRole names and type references and similar.


Hi Tony,
 
I am not sure why we need the name and type reference, can you give a
concrete example? As we don't have the concept of role instances, I would
assume that a single attribute (whether called name or type ref) would be
sufficient.
 
Regards
Gary

----- Original Message ----- 
From: Tony Fletcher <mailto:tony_fletcher@btopenworld.com>  
To: public-ws-chor@w3.org 
Sent: Saturday, March 19, 2005 11:04 PM
Subject: toRole and fromRole names and type references and similar.

Dear Colleagues,
 
In trying to sort out roletypes from roles for issues 1018 and 1018
I wonder if we should not change the interaction syntax defined in 2.5.2.3
from


                                                     Interaction Syntax


The syntax of the <emph>interaction</emph> construct is:



<interaction  name="ncname"

              channelVariable="qname"

              operation="ncname"

              align="true"|"false"?

              initiate="true"|"false"? >

 

   <participate  relationshipType="qname"

                 fromRole="qname" toRole="qname" />

 

   <exchange  name="ncname"

              informationType="qname"?|channelType="qname"?

              action="request"|"respond" >

     <send      variable="XPath-expression"? 

                recordReference="list of ncname"?   

                causeException="true"|"false"? />

     <receive   variable="XPath-expression"? 

                recordReference="list of ncname"? 

                causeException="true"|"false"? />

   </exchange>*

 

   <timeout  time-to-complete="XPath-expression"

             fromRoleRecordReference="list of ncname"?

             toRoleRecordReference="list of ncname"? />?

 

   <record  name="ncname"

            when="before"|"after"|"timeout"

            causeException="true"|"false"? >

     <source  variable="XPath-expression"? | expression="Xpath-expression"?
/>

     <target  variable="XPath-expression" />

   </record>*

</interaction>

to


                                                     Interaction Syntax


The syntax of the <emph>interaction</emph> construct is:



<interaction  name="ncname"

              channelVariable="qname"

              operation="ncname"

              align="true"|"false"?

              initiate="true"|"false"? >

 

   <participate  relationshipType="qname"

                 fromRole="ncnameqname" fromRoleType="qname"

                 toRole="ncnameqname" toRoleType="qname"

   />

 

   <exchange  name="ncname"

              informationType="qname"?|channelType="qname"?

              action="request"|"respond" >

     <send      variable="XPath-expression"? 

                recordReference="list of ncname"?   

                causeException="true"|"false"? />

     <receive   variable="XPath-expression"? 

                recordReference="list of ncname"? 

                causeException="true"|"false"? />

   </exchange>*

 

   <timeout  time-to-complete="XPath-expression"

             fromRoleRecordReference="list of ncname"?

             toRoleRecordReference="list of ncname"? />?

 

   <record  name="ncname"

            when="before"|"after"|"timeout"

            causeException="true"|"false"? >

     <source  variable="XPath-expression"? | expression="Xpath-expression"?
/>

     <target  variable="XPath-expression" />

   </record>*

</interaction>

 
That is that we should give the roles names as well as showing what type the
correspond to.
 
Similarly for perform.  Should we not change


<perform  choreographyName="qname" 

          choreographyInstanceId="XPath-expression"? >

   <bind  name="ncname">

     <this variable="XPath-expression" role="qname"/>

     <free variable="XPath-expression" role="qname"/>

   </bind>*

   Choreography-Notation?

</perform>

to


<perform  choreographyName="qname" 

          choreographyInstanceId="XPath-expression"? >

   <bind  name="ncname">

     <this variable="XPath-expression" role="ncname" roleTypeRef="qname"/>

     <free variable="XPath-expression" role="ncname" roleTypeRef="qname"/>

   </bind>*

   Choreography-Notation?

</perform>

 
I propose to change the syntax of assign from
 

<assign  roleType="qname">

   <copy  name="ncname" causeException="true"|"false"? >

      <source  variable="XPath-expression"?|expression="Xpath-expression"?
/>

      <target  variable="XPath-expression" />

   </copy>+

</assign>

to
 

<assign  role="ncname" roleType="qname">

   <copy  name="ncname" causeException="true"|"false"? >

      <source  variable="XPath-expression"?|expression="Xpath-expression"?
/>

      <target  variable="XPath-expression" />

   </copy>+

</assign>

 
I propose to change the syntax for noAction from 

 

<noAction roleType="qname? />

 

to 

 

<noAction role="ncname"? roleType="qname"? />

 

 
 
although having one place in a choreography where we say what roles are
involved and what the type of each role is would probably be better then
doing it in several places like this and having to check consistency.
Perhaps something like


<roleAssignments name="ncname" ">

   <roleAssignment role name="ncname" roleType="qname" />+

</roleAssignments>

 
then noAction would become

<noAction role="ncname"? />

 
and similar elsewhere.
 
 
 
 


Best Regards     Tony
A M Fletcher
 
Cohesions  (TM)
 
Business transaction management software for application coordination
www.choreology.com <http://www.choreology.com/> 
 
Choreology Ltd., 68 Lombard Street, London EC3V 9LJ     UK
Tel: +44 (0) 1473 729537   Mobile: +44 (0) 7801 948219
tony.fletcher@choreology.com     (Home: amfletcher@iee.org)

 
Received on Monday, 21 March 2005 12:46:42 UTC

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