Re: Accessibility of suBclass-fields from suPERclass (reflection)
On 16.08.2014 10:46, Andreas Leitgeb wrote:
Consistent maybe, but why cannot Base access these fields by default?
I'm not complaining about that extra setAccessibility(true), I just
would like to see an example of where a Base-class accessing its children
could be a security issue. I'm not talking of some arbitrary class
attempting access, but about the target class's parent (or grandparent)
class.
I'm probably unaware of some risk, and learning about it was my reason
for the posting.
If I understand your issue correctly: this is not about security but
about design principles. Dependency always goes up the inheritance
chain - not downwards. Meaning, all subclasses have knowledge about
their superclasses but not vice versa.
If you want a superclass to access subclass state you need to provide
means for it, e.g. defining abstract accessor or other methods in the
base class which then must be implemented in subclasses.
There are languages out there that handle this differently. For
example, in Ruby instance variables are immediately accessible for all
instance methods - regardless of their defining class. But then again,
Ruby has a quite different approach to visibility and accessibility.
Kind regards
robert
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