Re: bidirectional relations between nodes of the same type

[P . van Kemenade]

Hi

So basicaly all relations in mmbase are unidirectional. unidirectional 
meaning
that a relation may only exist from nodes of type A to nodes of type B.
ok ... that clarifies a lot

I agree, we really need a crystal clear definition of directionality.
I propose we simply start avoiding the word, because everybody seems 
to mean something else with it.
QED :-)

I think hank was proposing that bidir relations should actually be bidir
at the time of their creation; that their direction must be stored (& 
never swapped).
That is a whole new approach, am I right ?
it seems to conflict with the opening lines of this message.

Michiel calls this 'relatively unimportant' because -to him- bidir and 
unidir
are a matter of visibility of the relation in a given direction after 
they
have been created (which is the current practice).
Something you might call "bidir / unidir retrieval" or something.

ANY SWAPPING OF SOURCE AND
DESTIONATION SHOULD BE CONSIDERED A BUG.
Swapping of source and destination (should) only occur(s) if there is 
only an allowed relation in
that direction (and not the in the requested one).
but why would you swap fields at all ? the only argument I can think
of is editors (or editinterfaces) being fuzzy about what relation they
want to create; that is an interface matter, and should be solved
on that level. returning an error on invalid input seems appropriate.
(if type a and type b are the same. the system works in a complete new 
manner)
that was the original problem.

in this case, I suppose mmbase doesnt swap fields;
if such relations are unidir, would mmbase still recognize directions ?
and if  they are bidir ?
(in real life, i see no point in not seeing specific relations in a
certain direction at all. if some frontend doesnt want to use specific
relations, it's easy enough to recognize and ignore them)
thanks,
*pike
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