Re: Contradictions regarding transitivity of wsdl:import

I don't like this name change either.

Besides the confusion caused by the proposed name change, I find option
2 in Arthur's email a lot more appealing. Since David Booth called it
"a considerably clearer and more straightforward way to go", I would
suggest that examine it more carefully. My impression is that by
aligning the description component with the intuitive concept of a
description document, it will make things easier to grok for users.
The issues around component equivalence don't seem unsolvable.

By the way, I'm assuming that if we go with option 2, wsdl:include would
not cause a second Description component with the same targetNamespace
as the including document to appear but would simply add components to
the existing one.

Roberto


Yalcinalp, Umit wrote:
> Wouldn't this "name change" appear to imply that there are multiple 
> component models rather than multiple descriptions? That is more 
> confusing rather than clarifying IMO.
>  
> -1
>  
> --umit
>  
> 
>     ------------------------------------------------------------------------
>     *From:* www-ws-desc-request@w3.org [mailto:www-ws-desc-request@w3.org]
>     *Sent:* Tuesday, Apr 19, 2005 8:29 AM
>     *To:* Arthur Ryman
>     *Cc:* David Booth; www-ws-desc@w3.org; www-ws-desc-request@w3.org
>     *Subject:* RE: Contradictions regarding transitivity of wsdl:import
> 
>     OK, just wanted to make sure I'd understood the proposal. I think
>     that change is fine. If such a minor change clears up the confusion,
>     I'm all for it!!!
>     Gudge
> 
>         ------------------------------------------------------------------------
>         *From:* Arthur Ryman [mailto:ryman@ca.ibm.com]
>         *Sent:* Tuesday, April 19, 2005 8:18 AM
>         *To:* Martin Gudgin
>         *Cc:* David Booth; www-ws-desc@w3.org; www-ws-desc-request@w3.org
>         *Subject:* RE: Contradictions regarding transitivity of wsdl:import
> 
> 
>         Gudge,
> 
>         That's what I am proposing. What's your opinion?
> 
>         Arthur Ryman,
>         Rational Desktop Tools Development
> 
>         phone: +1-905-413-3077, TL 969-3077
>         assistant: +1-905-413-2411, TL 969-2411
>         fax: +1-905-413-4920, TL 969-4920
>         mobile: +1-416-939-5063, text: 4169395063@fido.ca
>         intranet: http://labweb.torolab.ibm.com/DRY6/
> 
> 
>         *"Martin Gudgin" <mgudgin@microsoft.com>*
>         Sent by: www-ws-desc-request@w3.org
> 
>         04/19/2005 10:35 AM
> 
>         	
>         To
>         	Arthur Ryman/Toronto/IBM@IBMCA
>         cc
>         	"David Booth" <dbooth@w3.org>, <www-ws-desc@w3.org>,
>         <www-ws-desc-request@w3.org>
>         Subject
>         	RE: Contradictions regarding transitivity of wsdl:import
> 
> 
>         	
> 
> 
> 
> 
> 
>         So, to summarize; the plan is to rename, at the component model
>         level, the 'Description' component to be called the 'Component
>         Model' component?
>          
>         Gudge
> 
>         ------------------------------------------------------------------------
>         *From:* Arthur Ryman [mailto:ryman@ca.ibm.com] *
>         Sent:* Tuesday, April 19, 2005 6:07 AM*
>         To:* Martin Gudgin*
>         Cc:* David Booth; www-ws-desc@w3.org; www-ws-desc-request@w3.org*
>         Subject:* RE: Contradictions regarding transitivity of wsdl:import
> 
> 
>         Martin,
> 
>         After your note, David phoned me and we talked for a long time.
>         The conversation pointed out to me that what I considered to be
>         the obvious interpretation of the component model was not so
>         obvious.
> 
>         My interpretation was that the Description component contained
>         all the components from all the documents. i.e., we are only
>         talking about a single component model instance. Any reference
>         from one component must land on another component within the
>         same Description component.
> 
>         However, David thought that the Description component mapped
>         more closely to the <description> element and that it contained
>         only those components that were "visible" to the components
>         defined in the document.
> 
>         I think this confusion could be reduced by adopting Option 1,
>         namely get rid of the Description component and replace it with
>         a new object named "Component Model". That would make is clear
>         that there is no close correspondence with a document.
> 
>         The Component Model object would contain the same properties as
>         the current Description component. These properties contain the
>         "root" components: interfaces, bindings, services, and types.
>         All other components are nested within the root components.
> 
>         Option 1 also has the benefit that we finally define the
>         Component Model in the same amount of detail as we define the
>         components. The spec refers to the component model a lot but
>         never actually defines in much detail.
> 
>         Arthur Ryman,
>         Rational Desktop Tools Development
> 
>         phone: +1-905-413-3077, TL 969-3077
>         assistant: +1-905-413-2411, TL 969-2411
>         fax: +1-905-413-4920, TL 969-4920
>         mobile: +1-416-939-5063, text: 4169395063@fido.ca
>         intranet: http://labweb.torolab.ibm.com/DRY6/
> 
>         *"Martin Gudgin" <mgudgin@microsoft.com>*
>         Sent by: www-ws-desc-request@w3.org
> 
>         04/18/2005 09:56 PM
> 
>         	
>         To
>         	"David Booth" <dbooth@w3.org>, Arthur Ryman/Toronto/IBM@IBMCA
>         cc
>         	<www-ws-desc@w3.org>
>         Subject
>         	RE: Contradictions regarding transitivity of wsdl:import
> 
> 
> 
>         	
> 
> 
> 
> 
> 
> 
> 
>         I didn't think this was where we ended up after my 'illumination'
>         e-mail... What happened?
> 
>         Gudge
> 
>          > -----Original Message-----
>          > From: David Booth [mailto:dbooth@w3.org]
>          > Sent: Monday, April 18, 2005 6:53 PM
>          > To: Arthur Ryman
>          > Cc: Martin Gudgin; www-ws-desc@w3.org
>          > Subject: RE: Contradictions regarding transitivity of wsdl:import
>          >
>          > On Mon, 2005-04-18 at 12:17, Arthur Ryman wrote:
>          > > David,
>          > >
>          > > I don't think this works in general. The reason is that
>         documents
>          > > refer to each other so there really isn't a component model
>         for each
>          > > document..
>          >
>          > I now understand that that is the current design of the component
>          > model.  I was suggesting that instead there should be a
>          > component model
>          > for each WSDL 2.0 document (i.e., each wsdl:description element
>          > information item), along the lines of option 2 that you
>         propose below.
>          >
>          > >
>          > > You could have a document that didn't refer to any other
>          > document, and
>          > > that would have a component model. That is a "leaf" node.
>          > >
>          > > Document can actually have circular references to
>          > eachother. The spec
>          > > permits this. The component model therefore must include
>         all the
>          > > components in order to satisfy the intercomponent references.
>          > >
>          > > My reading of the spec is that all components belong to a
>         single
>          > > instance of the component model. The instance is defined by
>         a root
>          > > document and the set of documents it references.
>          > >
>          > > There are two possible ways we could improve the clarity of
>          > the spec:
>          > >
>          > > Option 1. Rename the Description Component to the Component
>         Model
>          > >
>          > > This actually eliminates the Description component
>         altogether and
>          > > replaces it with an object called the Component Model. The
>          > spec talks
>          > > a lot about the component model, but never actually defines
>          > it. We can
>          > > make it clear that the component model contains all the
>         components
>          > > from all the documents processed.
>          > >
>          > > Option 2. Define the Component Model to be a set of Description
>          > > Components, and restrict each Description component to only
>         contain
>          > > the components defined in it
>          >
>          > Yes, I think this approach would be a considerably clearer
>         and more
>          > straightforward way to go.  However, I would nitpick about
>         the word
>          > "set".  "Directed graph" would be more precise:  A given WSDL 2.0
>          > document would have a single Description component, which may
>         refer to
>          > other Description components (if the original WSDL 2.0
>          > document imports
>          > other documents, for example), thus representing a directed
>         graph.
>          >
>          > >
>          > > This makes the mapping between Description components and
>         documents
>          > > clearer.
>          >
>          > Yes, and we need people to understand our spec.  We have already
>          > received complaints about how hard it is to understand.  
>          >
>          > > It introduces the technical subtlety of what to do about
>         duplicated
>          > > components. We currently allow duplicate components to come
>         from
>          > > different documents as long as the components are
>         equivalent. To
>          > > resolve component references, we need to pick a particular
>         component
>          > > among the set of equivant components (or formally introduce
>          > the notion
>          > > of equivalence class and make component references resolve
>          > to those).
>          >
>          > I think we have that subtlety already, but you're right it
>          > will have to
>          > be resolved differently.  There are several ways it could be
>          > handled.  I
>          > doubt equivalence classes would be needed.  One way is for each
>          > Description component to have an {imported descriptions}
>          > property.  Then
>          > if a new document is imported, ignore it if its corresponding
>          > Description component is already in that set.
>          >
>          >
>          > --
>          > David Booth <dbooth@w3.org>

Received on Tuesday, 19 April 2005 17:34:15 UTC