topicType

`topicType`
	NPCL XML Schema

`topicType`

This element describes a single Topic Type in the schema. It contains the Occurrence and Role Player Constraints that apply to this Topic Type.

<npcl:topicType id="..." abstract="true|false">
  <npcl:subjectIdentifier>
    ...
  </npcl:subjectIdentifier>
  <npcl:displayName>...</npcl:displayName>
  <npcl:rolePlayerConstraint 
      roleTypeRef="..." 
      associationTypeRef="..." 
      minCardinality="..." 
      maxCardinality="..."/>
  <npcl:occurrenceConstraint 
      occurrenceTypeRef="..." 
      minCardinality="..." 
      maxCardinality="..."/>
  <npcl:extension type="...">
    ...
  </npcl:extension>
  <npcl:subclasses> ... </npcl:subclasses>
</topicType>

npcl:topicType/@id

REQUIRED. An internal identifier for the type. This is used only for reference purposes inside the NPCL XML document.

npcl:topicType/@abstract

OPTIONAL. A boolean value that indicates if this type is abstract. If not specified, this attribute value defaults to "false".

npcl:topicType/npcl:subjectIdentifier

REQUIRED, REPEATABLE. Contains a subject identifier URI for the type.

npcl:topicType/npcl:displayName

Contains a human-readable display label for the type.

npcl:topicType/npcl:rolePlayerConstraint

This element specifies a single Role Player Constraint that applies to this Topic Type.

The roleTypeRef attribute is REQUIRED and contains the internal identifier of the Role Type that is allowed by the Role Player Constraint. This must match the value of the id attribute on a roleType element in the NPCL XML document.

The associationTypeRef attribute is OPTIONAL and contains the internal identifier of the Association Type that is allowed by the Role Player Constraint. This must match the value of the id attribute on an associationType element in the NPCL XML document. If this attribute is ommitted, then the Role Player Constraint applies to all roles of the specified Role Type, regardless of the type of association they are in.

The minCardinality attribute specifies the Minimum Cardinality Facet for the constraint. This attribute is REQUIRED and its value must be a non-negative integer.

The maxCardinality attribute specifies the Maximum Cardinality Facet for the constraint. This attribute is REQUIRED and its value must be either a non-negative integer or the string value "unbounded" (indicating that there is no upper limit on this constraint.

npcl:topicType/npcl:occurrenceConstraint

This element specifies a single Occurrence Cosntraint that applies to this Topic Type.

The occurrenceTypeRef attribute is REQUIRED and contains the internal identifier of the Occurrence Type that is allowed by the Occurrence Constraint. This must match the value of the id attribute on an occurrenceType element in the NPCL XML document.

The minCardinality attribute specifies the Minimum Cardinality Facet for the constraint. This attribute is REQUIRED and its value must be a non-negative integer.

npcl:topicType/npcl:extension

Contains a single typed extension value for the type. The value is the string content of this element. The type is specified as a URI in the type attribute of this elment.

npcl:topicType/npcl:subclasses

Contains a list of the subclasses of this type. This element structure is described in detail below.


`abstractType` Element		`occurrenceType` Element