Property and Value handles

Property handles form a hierarchical structure, where each property handle represents a property (collection or reference) in an instance hierarchy. A property handle contains a pointer, which refers to a handle (property) node in a property handle hierarchy. Property nodes, which are referred from the Property handle, provide instance, cursor and metadata functionality.

Property handles can be constructed or opened. It does not make any difference for the property handle, how it has been created. Since a property handle is nothing else than a pointer to a property cursor, which handles collections and selected instances, constructing or opening a property handle just provides a property node pointer in the property handle.

For most constructor functions equivalent open() functions have been provided, i.e. in contrast to upper handles one may open a property handle implicitly by calling the constructor. When opening property handles in OSI, the open() function has to be called explicitly.

For accessing object instance data (attributes), value handles provide appropriate access functionality. instance and cursor functionality.