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 Propagation of Objects Exposed at a Package InterfaceLocate this document in the navigation structure

The package concept allows for the propagation of objects of a subpackage's interfaces, and also of objects of any other usable package interface. For both kinds of propagation the following rules apply:

At a package interface of a package X, individual objects from any package interface that is usable from X can be exposed, provided their original package interface allows their propagation.

It is allowed to expose not only single objects of such an original interface, but to expose its complete contents, provided this original interface is marked as propagatable as a whole:

  • Exposing the contents of a whole original interface can be done by including a special pseudo object into the propagating package interface.
  • By including this pseudo object, all objects exposed at the original interface at any given time are included in the propagating interface. If the set of these objects changes (for example, by new objects being added to the original interface), the changes affect the propagating interface accordingly.
  • Further properties of the original interface (such as its access control list and its name) are not transferred to the propagated interface.
  • Marking the pseudo object as propagatable means granting all the propagating interface's clients the permission to propagate all objects of the original interface represented by the pseudo object.

At the propagating interface, the possible list of usage types for the propagated objects can be kept as it is or it can be restricted further. However, the propagating interface cannot assign additional usage types.