Issue 2174:  Add support for default values to MofAttribute (mof-rtf)
Source:  (, )
Nature:  Revision
Severity:  Significant
Summary: Summary: It has been suggested that Model should be extended to allow
 attributes to specified to have default values. Default values can be
 defined in the MOF Model by adding an attribute of type "any" to
 MofAttribute.  [Default expressions are too hard.]
 
 

Resolution: 
Revised Text: 
Actions taken:
November 6, 1998: received issue
July 23, 1999: Deferred
Discussion: 
The following alternatives are available for default constructors in the specific interfaces:
1. If an Attribute has a default value, the corresponding specific create operation has
no initialiser parameter for that attribute.
2. When necessary, provide two constructor / factory operations in the specific inter-faces,
one with initialisers for attributes with defaults, one without.
3. No support for default initialisation in specific factory operation. The client must
use the Reflective operation to get default constructor behaviour.
In the Reflective interface, there are various options. For example:
1. Parameters are positional, with nil Any values as position holders and trailing pa-rameters
possibly omitted.
2. Parameters are Designator / Value pairs, supplied in any order. This requires an
operation signature change.
Discussion: (crawley@dstc.edu.au)
Of the alternatives available, I prefer alternative 2 for specific interfaces and alternative 1
for reflective interfaces. However, I would prefer to treat this as out of scope of the RTF,
since there is no pressing need for default values
MOF RTF Burlingame - Deferred to MOF 2.0. This is an extension to the MOF and a po-tentially
useful one. The following alternatives are available for default constructors in the specific interfaces: 

If an Attribute has a default value, the corresponding specific create operation has no initialiser parameter for that attribute. 
When necessary, provide two constructor / factory operations in the specific inter-faces, one with initialisers for attributes with defaults, one without. 
No support for default initialisation in specific factory operation. The client must use the Reflective operation to get default constructor behaviour. 
In the Reflective interface, there are various options. For example: 
Parameters are positional, with nil Any values as position holders and trailing pa-rameters possibly omitted. 
Parameters are Designator / Value pairs, supplied in any order. This requires an operation signature change 

End of Annotations:=====
Return-Path: <crawley@dstc.edu.au>
To: mof-rtf@omg.org, issues@omg.org
Subject: Add support for default values to MofAttribute
Date: Fri, 06 Nov 1998 13:54:01 +1000
From: Stephen Crawley <crawley@dstc.edu.au>


["new issue 4" from Seattle RTF doc.]

Source: DSTC (Dr. Stephen Crawley, crawley@dstc.edu.au)
Nature: Revision
Severity: Significant
Summary: It has been suggested that Model should be extended to allow
attributes to specified to have default values. Default values can be
defined in the MOF Model by adding an attribute of type "any" to
MofAttribute.  [Default expressions are too hard.]

The following alternatives are available for default constructors in
the specific interfaces:

1) If an Attribute has a default value, the corresponding specific
create operation has no initialiser parameter for that attribute.

2) When necessary, provide two constructor / factory operations in the
specific interfaces, one with initialisers for attributes with
defaults, one without.

3) No support for default initialisation in specific factory
operation. The client must use the Reflective operation to get default
constructor behaviour.

In the Reflective interface, there are various options. For example:

1) Parameters are positional, with nil Any values as position holders
and trailing parameters possibly omitted.

2) Parameters are Designator / Value pairs, supplied in any
order. This requires an operation signature change.

[My preference is alternative 2 for specific interfaces and
alternative 1 for reflective interfaces.]