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Often a class has an attribute for which many of the class instances will assign the same value to that attribute. Reading
and write this same attribute-value pair is very tedious. Therefore, the HUTN supports the shorthand of omitting the attribute-value
pair if the value is intended to be the default value. Note that the default value cannot be determined from the MOF model
and so user/modeler input is needed. Default values for an attribute on a class are configured using the DefaultValueConfig
metaclass (see 5.1.8, “DefaultValueConfig?).
The effect of this on an HUTN producer is that the attribute’s representation need not be shown if its value is the same as
its default value. For a consumer, the absence of the attribute in the object declaration can be taken to mean that it has
as its value the attribute’s default value.
Since classes that use an attribute as an identifier must be identified, an attribute selected as such may not be assigned
a default value. Similarly, attributes configured
for parametric display (as described in 4.3.6, “Parametric Form?) are also not
configurable for a default value. As described in 4.3.2, “Keywords and Adjectives,?
the use of a default value on a single-valued boolean-valued attribute affects the behavior of its keyword and adjective forms.