+
+ # update the bbox of the changeset and save it too.
+ # discussion on the mailing list gave the following definition for
+ # the bounding box update procedure of a relation:
+ #
+ # adding or removing nodes or ways from a relation causes them to be
+ # added to the changeset bounding box. adding a relation member or
+ # changing tag values causes all node and way members to be added to the
+ # bounding box. this is similar to how the map call does things and is
+ # reasonable on the assumption that adding or removing members doesn't
+ # materially change the rest of the relation.
+ any_relations =
+ changed_members.collect { |id,type| type == "relation" }.
+ inject(false) { |b,s| b or s }
+
+ if tags_changed or any_relations
+ # add all non-relation bounding boxes to the changeset
+ # FIXME: check for tag changes along with element deletions and
+ # make sure that the deleted element's bounding box is hit.
+ self.members.each do |type, id, role|
+ if type != "relation"
+ update_changeset_element(type, id)
+ end
+ end
+ else
+ # add only changed members to the changeset
+ changed_members.each do |id, type|
+ update_changeset_element(type, id)
+ end
+ end
+
+ # tell the changeset we updated one element only
+ changeset.add_changes! 1
+
+ # save the (maybe updated) changeset bounding box
+ changeset.save!
+ end
+ end
+
+ ##
+ # updates the changeset bounding box to contain the bounding box of
+ # the element with given +type+ and +id+. this only works with nodes
+ # and ways at the moment, as they're the only elements to respond to
+ # the :bbox call.
+ def update_changeset_element(type, id)
+ element = Kernel.const_get(type.capitalize).find(id)
+ changeset.update_bbox! element.bbox
+ end
+
+ def delete_with_history!(new_relation, user)
+ if self.visible
+ check_consistency(self, new_relation, user)
+ if RelationMember.find(:first, :joins => "INNER JOIN current_relations ON current_relations.id=current_relation_members.id", :conditions => [ "visible = ? AND member_type='relation' and member_id=? ", true, self.id ])
+ raise OSM::APIPreconditionFailedError.new
+ else
+ self.changeset_id = new_relation.changeset_id
+ self.tags = {}
+ self.members = []
+ self.visible = false
+ save_with_history!
+ end
+ else
+ raise OSM::APIAlreadyDeletedError.new
+ end
+ end
+
+ def update_from(new_relation, user)
+ check_consistency(self, new_relation, user)
+ if !new_relation.preconditions_ok?
+ raise OSM::APIPreconditionFailedError.new
+ end
+ self.changeset_id = new_relation.changeset_id
+ self.tags = new_relation.tags
+ self.members = new_relation.members
+ self.visible = true
+ save_with_history!
+ end
+
+ def create_with_history(user)
+ check_create_consistency(self, user)
+ if !self.preconditions_ok?
+ raise OSM::APIPreconditionFailedError.new