MDMI_ — Explicit datatypes in datatype rule

The DataRule rules are dealing with datatypes. It will be difficult to find a rule language and complex to write rules unless the structures of the datatypes (especially complex datatypes) in the rule are explicit and discoverable.

Even though datatypes are not part of the standard, there are restrictions required for the form of datatypes, especially complex datatypes. Section 8.4 of the document will be revised to take into account these requirements. The specific change to the model will be to include a "datatype" attribute in the "DataRule" class with a multiplicity of [1...*] to provide explicit references to the datatypes used in the rule expression. This is necessary so that DataRules expressions can be properly parsed.
While the class specification for DataRule does not change much, a large amount of explanatory text is included in the Beta 2 document to properly resolve this issue. First, there is the addition of a URI "reference" property in the MDMIDatatype class. In addition, associations are removed from the MDMIDatatype class and the MDMIDatatype class is simply used to define the type of any "datatype" property in the model. This was necessary in order to define the type for DataRule's new property, "datatype".
Then a section is added that presents an example of a metamodel for a "complex datatype" so the need for the explicit "datatype" property is clearer, as it exposes the type of structure that a DataRule language would have to access.