Summary of Restrictions when Using Packages

When using packages, you should be aware of the following restrictions.

• You cannot export any of the following.

  • Imported classes.

  • Inherited properties and methods on a subclass. To export an inherited method, you must export the superclass or reimplement the inherited method on the exported class.

  • A RootSchema subschema copy class.

  • Subclasses of the Application, Global, or WebSession class.

  • Any system (that is, RootSchema) classes; for example, the Object or the Dictionary class.

  • Constructor (create) or destructor (delete) methods.

  • Event methods (for example, the timerEvent method, notification event methods, and control event methods), nor can you re-implement them in the importing schema.

  • Global constants.

  • External functions.

  • Properties that have protected access.

• As class names must be unique within a package, a single package cannot export both a class and a subschema copy of that class.

• Package names must be unique within a schema, across both imported and exported packages.

• A schema that exports a package cannot also import it. Schemas cannot import any packages that were exported from the same schema branch.

• Imported classes cannot participate in inverse relationships with local classes.

• You cannot subclass imported classes.

• A class can be imported once only, from one package only, within a specific schema branch. You cannot import a class more than once into a schema branch.

• You cannot remap imported classes to different database files.

• You cannot add local mapping methods to imported classes.