+ ##
+ # the bounding box around a node, which is used for determining the changeset's
+ # bounding box
+ def bbox
+ [ longitude, latitude, longitude, latitude ]
+ end
+
+ # Should probably be renamed delete_from to come in line with update
+ def delete_with_history!(new_node, user)
+ unless self.visible
+ raise OSM::APIAlreadyDeletedError.new("node", new_node.id)
+ end
+
+ # need to start the transaction here, so that the database can
+ # provide repeatable reads for the used-by checks. this means it
+ # shouldn't be possible to get race conditions.
+ Node.transaction do
+ check_consistency(self, new_node, user)
+ way = WayNode.find(:first, :joins => "INNER JOIN current_ways ON current_ways.id = current_way_nodes.id",
+ :conditions => [ "current_ways.visible = ? AND current_way_nodes.node_id = ?", true, self.id ])
+ raise OSM::APIPreconditionFailedError.new("Node #{self.id} is still used by way #{way.id}.") unless way.nil?
+
+ rel = RelationMember.find(:first, :joins => "INNER JOIN current_relations ON current_relations.id=current_relation_members.id",
+ :conditions => [ "visible = ? AND member_type='Node' and member_id=? ", true, self.id])
+ raise OSM::APIPreconditionFailedError.new("Node #{self.id} is still used by relation #{rel.relation.id}.") unless rel.nil?
+
+ self.changeset_id = new_node.changeset_id
+ self.visible = false
+
+ # update the changeset with the deleted position
+ changeset.update_bbox!(bbox)
+
+ save_with_history!
+ end
+ end
+
+ # As above but doesn't throw an error if node is used elsewhere - instead, just silently
+ # returns without deleting the node. Potlatch needs this in case you ask to delete an
+ # off-screen node while deleting a way - it doesn't know whether the node is used
+ # elsewhere or not.
+ def delete_with_history_unless_used!(new_node, user)
+ unless self.visible
+ raise OSM::APIAlreadyDeletedError.new("node", new_node.id)
+ end
+
+ Node.transaction do
+ check_consistency(self, new_node, user)
+ way = WayNode.find(:first, :joins => "INNER JOIN current_ways ON current_ways.id = current_way_nodes.id",
+ :conditions => [ "current_ways.visible = ? AND current_way_nodes.node_id = ?", true, self.id ])
+ rel = RelationMember.find(:first, :joins => "INNER JOIN current_relations ON current_relations.id=current_relation_members.id",
+ :conditions => [ "visible = ? AND member_type='Node' and member_id=? ", true, self.id])
+ if way.nil? and rel.nil?
+ self.changeset_id = new_node.changeset_id
+ self.visible = false
+ changeset.update_bbox!(bbox)
+ save_with_history!