Re: [COAS-List] Some Ideas from the UML Spec

[Tim Brinson <tim@protocol.com>]

Tom Culpepper wrote:
> TCC - any luck and way a "+" in front of the role indicates?

The visibility of an attribute can be specified as:

	'+' for public visibility

	'#' for protected visibility

	'-' for private visibility

"The visibility marker may be suppressed. The absence of a visibility
marker indicates that the visibility is not shown (not that it is
undefined or public)."

"Additional kinds of visibility might be defined for certain programming
languages, ...(actually all forms of nonpublic visibility are
language-dependent)."

For now it seems we could suppress the visibility markers since I
believe all attributes are public.  If we add operations in the future
we MAY want to start hiding some of the attributes (making them
private).  For example OBV does allow specifying state as public or
private.  

While I think having operations and private state for OBV is valuable
(for vendor specific work) it may not be as applicable in standard
specifications.  If we have operations on the objects that get passed by
value then the client system has to implement them.  Think about that
for a while.  Currently clients only have to compile the IDL and call
operations - the server (or a local ORB library) is where the operations
are always implemented.  Do we really want to put the burden on clients
to implement operations too (whether they need them or not)?  Although
it may be OK to put operations in the conceptual model (UML) - I haven't
thought through the ramifications of that.


Tim
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