RE: [xml-dev] Are people really using Identity constraints specif ied in XML schema?

From
Bullard, Claude L (Len) <>
To
"Bullard, Claude L (Len)" <>, 'Michael Kay' <>, "'Roger L. Costello'" <>,
Date
2004-08-23T14:55:17Z
ID
<>
Thread
RE: [xml-dev] Are people really using Identity constraints specif ied in XML schema?
Let's ask the question another way.  Considering that a schema 
only knows how to do one thing, test conformance of an instance 
to itself, where should a schema sit in a model-view-controller 
architecture?  

A user interface is likely doing all of the following:

"
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnpag/html/
uipab-ch01.asp
1 Managing the flow of information through the user interface components 
2 Managing the transitions between stages of a user interface process 
3 Modifying user process flow in response to exceptions 
4 Separating the conceptual user interaction flow from the implementation or
device where it occurs 
5 Maintaining internal business-related state, usually by holding on to one
or more business entities that are affected by
  the user interaction 
6 Accumulating data taken from many UI components to perform a batch update
at the server 
7 Keeping track of the progress of a task in a user interface process"

It seems to me that items 3,5 and 6 are pertinent.  Would I want to use the
schema 
to find exceptions that modify user process flow given this also affects
transition 
management?  Likely not.  Maintain internal business state?  No.  Verify
that data 
taken from many components are valid priot to performing a batch update?
Ok. That 
looks like a good candidate.  But is it?

len