At 10:37 +0200 24-05-2005, Michiel Meeuwissen wrote:
> The implementation in
org.mmbase.bridge.BasicRelationManager#mayCreateRelation
only checks against security.
So why not change that? You showed how to do it!
I'm afraid it will break functionality in other
uses of the bridge, for example the EditWizards.
In the EditWizards it is possible to create a
relation without explicitly specifying whether it
is from source to destination or from destination
to source iirc.
> Next when a
relation is created in
BasicRelationManager#createRelation it checks if
the relation is valid in
> BasicRelation#checkValid() which 'looks' at both
sides of the relation: it first checks whether
source -> destination is present in TypeRel and
then reverses it and checks destination -> source
;-) IIRC a relation with either direction is
valid on the bridge.
In taglib the createrelation tag throws an
exception when you try to create a relation with
the wrong directionality. So in a way this code
is now in the right spot.
I think it is weird that the tag throws an exception and the bridge does
not, while the tag does nothing more than calling a bridge function:
RelationManager rm = getCloudVar().getRelationManager(role.getString(this));
Node sourceNode = getNode(source.getString(this));
Node destinationNode = getNode(destination.getString(this));
Relation r = rm.createRelation(sourceNode, destinationNode);
r.commit();
So, that means that RelationManager#createRelation throws an excpetion
when you turn source and destination around.
True.
That would make perfect sense to me, though the 'turn-around'
functionality about which you speaks sounds familiar too.
I think there must be symmetry in the bridge in the first place. You
cannot have checked 'mayCreateRelation' and then to find that the relation
you make with excactly the same arguments in 'createRelation' gives an
excpetion informing that you are not allowed.
That ambiguity lives in
org.mmbase.corebuilders.InsRel#alignRelNode() i
found out. It reverses the direction when it
encounters a relation that it does not recognize.
Then InsRel tries to swap them to produce a
correct relation node.
Allthough I would not be be against working around such issues in the
taglib if necessary, I don't quite understand yet what is going on in
bridge here, and I have the feeling that the problem which you try to
solve here, would occur in bridge-only code too, because the
tag-implementations were so very straight-forward.
I agree. And in this i believe the bridge to be correct.
---Andr�
--
Andr� van Toly
http://www.toly.nl mobile +31(0)627233562
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