Re: [ebxml-bp] Dynamic (late) binding proposal - take 3 now withdiagram

["Anders W. Tell" <anderst@toolsmiths.se>]

David RR Webber wrote:

>However - we need to recognize that having a generalized
>mechanism in place - negates the need for continual
>schema changes in the future - that's the whole point.
>So - while for the specific TTP need we've opened that
>up because of a specific short term use case- in general future
>use cases should be seeking to use the external
>context system - rather than burdening the base
>schema with yet more complexity.
>  
>
I think we need exact semantics defined where it belongs and adding 
external references to highly flexible context programming languages 
makes the whole situation very difficult to overlook. I dont think a 
system developers need a context programming language when they can use 
XSLT. 

Another aspect is that BPSS is a Contract between parties and the 
parties have to be carefull on what they put in there.

Using external references to a mechanism that allows you to do anything 
including exchanging information between business partner is making BPSS 
obsolete. The trick with specs such as BPSS is to know exactly what to 
put in there and not, separation of concerns.

Problems with external references include:
* what happens when the referenced dockument is not available?
* how do you make sure that both parties has the same version?
* how do you verify that the referenced dockument you has not changed 
during execution?
* how to verify above in case of dispute?
* what is the effect of basing decisions on values that are not 
available to both parties?
  (which happens if you link and switch based on information not 
prevously exchanged
   such as asking an internal business system for information)


>Also - and this is critical - implementations that use
>schema level tweaks are hidden and not able to
>expose these to the business level - for verification.
>  
>
I dont see how above statement work in practice since XSD itself doest 
cary semantics, could you elaborate?

>Not to mention potential schema parser issues.
>  
>
Must be the trivial part, with so many XSD experts in the group ;)


cheers
/ander
-- 

/////////////////////////////////////
/ Business Collaboration Toolsmiths /
/ website: <www.toolsmiths.se>      /
/ email: <anderst@toolsmiths.se>    /
/ phone:  +46 8 562 262 30          /
/ mobile: +46 70 546 66 03          /
/////////////////////////////////////