Dan, two questions.
- I must be missing something,
but what is the sense of a property having two (or more) “initial”
values?
- I believe there is a difference
between an initial and a default value. An initial value is the
value that of a property upon setting up the property (e.g. creating the
instance that has the property). A default value is the value of the
property when a value is not otherwise specified for it. The
semantics are slightly different—e.g., the client might be primarily
interested in the default value of a property is the server does not
provide a value; the initial value is always established by the server.
Which semantics are you intending for wsrmd:InitialValues?
Kirk Wilson
Architect, Development
Office of the CTO
603 823-7146
-----Original Message-----
From: Daniel Jemiolo [mailto:danjemiolo@us.ibm.com]
Sent: Thursday, April 06, 2006
2:40 PM
To: wsrf@lists.oasis-open.org
Subject: [wsrf] Proposed
resolution - re: InitialValues for properties in WS-RMD
On the TC call on 4/3/06, I proposed that we (re-)add
the concept of initial values to the WS-RMD spec. This issue does not have a
number yet. Below is a description of the issue and the proposed resolution.
When
programming against the RMD spec, it is often necessary to seed a property with
a set of initial values that are known at design time. A better term might be
"default" values. The difference between these initial values and the
concept of static values already in the spec is that initial values should be
mutable, while static values are not.
The
definition of initial values in an RMD document would be just like that of
static values. For example, a property named MyProperty of type integer might
have the following definition:
<wsrmd:Property
path="myns:MyProperty" ... >
<wsrmd:InitialValues>
<myns:MyProperty>123</myns:MyProperty>
<myns:MyProperty>456</myns:MyProperty>
</wsrmd:InitialValues>
</wsrmd:Property>
If
the property is mutable, these initial values may be deleted or updated over
the resource's lifetime. Again, this is different from static values because
even on mutable properties, static instances are never deleted or updated.
The
proposed resolution is to add the initial values concept to RMD by copying the
section on static values (8.4), doing a search-and-replace (StaticValues ->
InitialValues), and modifying the two introductory sentences to describe the
role of initial values. The schema and infoset figures (in section 8 and
appendices) will also need to be updated to reflect this option.
Dan Jemiolo
IBM Corporation
Research Triangle Park, NC
+++ I'm an engineer. I make slides that people can't read. Sometimes I eat
donuts. +++