OBJECT REFERENCE phrase

Syntax rules

1. The USAGE OBJECT REFERENCE clause should only be specified on level 01 or within a type description entry with the attribute STRONG. Deviations are permitted as an extension.

2. The USAGE OBJECT REFERENCE clause may not be specified on the group level in data definitions.

3. The USAGE OBJECT REFERENCE clause may not be specified in the FILE SECTION.

4. The ACTIVE-CLASS phrase may be specified only in a factory definition, an object definition, or a method definition.

5. The USAGE OBJECT REFERENCE clause may not be specified in structures in which the EXTERNAL or DYNAMIC clauses are used on level 01.

6. No VALUE clauses may be specified for data items defined with a USAGE OBJECT REFERENCE clause.

7. Data items to which a USAGE OBJECT REFERENCE clause applies may have neither a REDEFINES clause, nor be referenced directly from any such clause. In addition, these data items may not be indirectly contained in any redefined or redefining structure.

8. Data items and structures to which a USAGE OBJECT REFERENCE clause applies may not be renamed (with a RENAMES clause).

9. For groups that have defined data items with a USAGE OBJECT REFERENCE clause, no VALUE clause may be specified on the group level.

10. No condition name (level number 88) may be specified for data items with a USAGE OBJECT REFERENCE clause.

11. The data item specified in the KEY phrase of an OCCURS clause may not be defined with a USAGE OBJECT REFERENCE clause.

General rules

A data item described with a USAGE OBJECT REFERENCE clause is an object reference. The following rules apply:

1. If none of the optional phrases is specified, this data item is called a universal object reference. Its content may be a reference to any object.

2. interface-name and class-name must be the names of the containing interface and class definitions, respectively, or must be listed accordingly in the REPOSITORY paragraph.

3. If interface-name-1 is specified, the object referenced by the data item be an object whose interface conforms with interface-1.

4. If class-name-1 is specified, the object referenced by this data item must be an object of the class identified by class-name-1 or of a subclass thereof, subject to the following rules:

   1. If the ONLY phrase is not specified, but the FACTORY phrase is used, the object referenced by this data item must be the factory object of the associated class or a subclass thereof. If FACTORY is not specified, the object referenced by this data item must be an object of the specified class or a subclass thereof.

   2. If the ONLY phrase is specified, then the same rules apply as given under a), except that no reference to a subclass is possible.

5. If ACTIVE-CLASS is specified, the object referenced by this data item must be an object of the class of the object that was used to invoke the method in which the object reference is defined. If FACTORY is specified, then the object reference refers to the factory object of that class; otherwise, to an object of that class.