Last Update Monday, June 18, 2001 10:24 AM
|1.0||18 June 2001||K. Schopmeyer|
In reviewing the changes needed to enable the property list, it was noted that the CIM Operations over HTTP specification clearly states that the possible definitions for proertylist are:
Further, NULL is the default if the propertylist parameter is not included in the request. However we are today defining an empty array as the default. In fact, we do not have the concept of NULL.
The concept of NULL is defined in the document CIM Operations over HTTP specificaion as follows
This notation uses the NULL qualifier to indicate parameters whose values may be specified as NULL in a method call. A NULL (unassigned) value for a parameter is specified by an <IPARAMVALUE> element with no subelement. For parameters which do not possess the NULL qualifier, the CIM Client MUST specify a value for the parameter by including a suitable subelement for the <IPARAMVALUE> element for that parameter.
NULL is referenced in the CIM specification as follows
All types can be initialized to the predefined constant NULL, which indicates no value has been provided. The details of the internal implementation of the NULL value are not mandated by this document.Thus we have to be able to support the concept of NULL on any CIM type and in particular to values.
It would appear that we need to implement the concept of NULL in general on CIMValue to be compliant with the CIM specifications. Doing this will allow us to then correctly implement the NULL in the property list also. In effect, this becomes a qualifier on each CIMValue
The areas that we appear to have to change include the following:
NOTE: There has been some discussion of the possibility of adding the concept of UNKNOWN to CIMValue in addition to NULL. However, this is not in any of the specifications today and we see not reason to consider it further unless it is proposed as an extension to the CIM Specification.
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