Nested classes can access static fields, properties and methods within the containing classes using the syntax:
self::memberName
The optional SHARING PARENT phrase in the nested class definition enables the nested class to access the instance fields, properties and methods in the containing class.
class-id ContainingClass.
...
class-id Nested1.
...
end class.
class-id Nested2 sharing parent.
...
end class.
end class.
Nested classes with the SHARING PARENT phrase may only be instantiated from within an instance method in the enclosing class. They can access the instance members from that containing class using the self:: syntax, even when those instance members are private.
Such a nested class contains an implicit reference to an instance of its containing class. The nested class uses this reference to access the enclosing class's instance members. This means that the containing class instance will not be garbage collected until all references to the inner class held externally have themselves been garbage collected.
For example:
class-id ContainingClass.
01 companyName string value "Micro Focus".
method-id instance1.
01 o type Nested2.
set o to new Nested2
...
end method
class-id Nested2 SHARING PARENT.
method-id method2
display self::companyName
end method.
end class.
end class.
Nested classes defined without the SHARING PARENT phrase may be declared as public, private or internal. Depending on the visibility specified, they can be instantiated from any context, not just from the containing class, and not just from instance methods. They cannot access instance members of the containing class with the self:: syntax, but only do it using an explicit object reference.