RE: [wsrf] Issue WSRF9

["Murray, Bryan P." <bryan.murray@hp.com>]

Tim,

I was not asking about a use-case for dynamic properties, but for a
use-case that requires a schema to be retrieved at runtime from a
WS-Resource for dynamic properties.

Bryan

-----Original Message-----
From: Tim Banks [mailto:tim_banks@uk.ibm.com] 
Sent: Monday, June 21, 2004 11:19 AM
To: Vambenepe, William N
Cc: wsrf@lists.oasis-open.org; Heather Kreger
Subject: Fw: [wsrf] Issue WSRF9







Hi William,

I (like Bryan) have been wondering what use cases there are for the
dynamic use of properties alluded to by issue 9  and it was suggested to
me that
WSDM may have some (and you are the link man with WSDM).   Perhaps the
WSDM
group could give us some input?

Regards, Tim Banks
IBM TP Architecture & Technology. Hursley, UK.
Phone: External +44 1962 815639, Internal 245639
----- Forwarded by Tim Banks/UK/IBM on 21/06/2004 19:16 -----

"Murray, Bryan P." <bryan.murray@hp.com> wrote on 21/06/2004 18:07:15:

>    I understand the need to know which properties are currently 
> present
>    in the property document given that the property document supports
>    dynamic properties. However, I would like to see a use-case
> describing
>    the need to retrieve at runtime the schema for any properties.
>
>    The only reason I can think of for retrieving properties which an
>    application does not already understand is if the application
> simply
>    displays properties to a human or copies the property somewhere.
> If
>    the application understands the namespace of the property it can
>
>    locate the type from the WSDL/schema for the namespace. Otherwise,
>    simple properties (no child XML elements) can be displayed
> without
>    understanding their type by just treating the text node as a
> string.
>    The application can choose to either not display complex
> properties or
>    to list attributes and child elements with their values.
> Grandchild
>    elements or attributes will ultimately make this too complicated
> to do
>    at some point.
>
>    Other, more complex, applications will need to understand not only 
> the
>    syntax of the properties they are retrieving, but also the 
> semantics
>    of those properties in order to interact with them appropriately. 
> The
>    syntax can be found in WSDL/schema files, but the semantics needs 
> to
>    be understood by the programmer writing the property retrieval 
> code. I
>    am confused as to how an application could interact with a property

> it
>    does not understand beyond simply displaying or copying its value. 
> If
>    an application does understand a property that falls into the 
> xsd:any
>    portion of the resource property document schema, it does not need 
> the
>    schema - it already knows the type of this property.
>
>    If there is no need beyond displaying or copying the value of an
>
>    unknown property I suggest that we not provide the ability to 
> retrieve
>    the schema at runtime.
>
>    Can someone offer a use-case that shows where my thinking is
>    deficient?
>
>    Bryan
>