WIP try to handle constraint violations involving more than one column

1              else:
2                  continue
3              break
4          else:
5              assert 0
6 -        key = rschema.type + '-subject'
7 -        # use .get since a constraint may be associated to an attribute that isn't edited (e.g.
8 -        # constraint between two attributes). This should be the purpose of an api rework at some
9 -        # point, we currently rely on the fact that such constraint will provide a dedicated user
10 -        # message not relying on the `value` argument
11 -        value = self.entity.cw_edited.get(rschema.type)
12 -        msg, args = constraint.failed_message(key, value, self.entity)
13 +        rtype = rschema.type
14 +        # if the constraint involves more than one column, try to find one which was modified
15 +        if rtype not in self.entity.cw_edited:
16 +            from yams.constraints import Attribute
17 +            if constraint.type() == 'BoundaryConstraint':
18 +                if isinstance(constraint.boundary, Attribute) and constraint.boundary.attr in self.entity.cw_edited:
19 +                    rtype = constraint.boundary.attr
20 +            elif constraint.type() == 'IntervalBoundConstraint':
21 +                if isinstance(constraint.minvalue, Attribute) and constraint.minvalue.attr in self.entity.cw_edited:
22 +                    rtype = constraint.minvalue.attr
23 +                elif isinstance(constraint.maxvalue, Attribute) and constraint.maxvalue.attr in self.entity.cw_edited:
24 +                    rtype = constraint.maxvalue.attr
25 +        key = rtype + '-subject'
26 +        msg, args = constraint.failed_message(key, self.entity, rtype)
27          raise ValidationError(self.entity.eid, {key: msg}, args)