+ def delete_with_history!(new_way, user)
+ unless self.visible
+ raise OSM::APIAlreadyDeletedError
+ 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.
+ Way.transaction do
+ check_consistency(self, new_way, user)
+ if RelationMember.find(:first, :joins => "INNER JOIN current_relations ON current_relations.id=current_relation_members.id",
+ :conditions => [ "visible = ? AND member_type='way' and member_id=? ", true, self.id])
+ raise OSM::APIPreconditionFailedError
+ else
+ self.changeset_id = new_way.changeset_id
+ self.tags = []
+ self.nds = []
+ self.visible = false
+ save_with_history!
+ end
+ end
+ end
+
+ # delete a way and its nodes that aren't part of other ways, with history
+
+ # FIXME: merge the potlatch code to delete the relations
+ # and refactor to use delete_with_history!
+ def delete_with_relations_and_nodes_and_history(changeset_id)
+ # delete the nodes not used by other ways
+ self.unshared_node_ids.each do |node_id|
+ n = Node.find(node_id)
+ n.changeset_id = changeset_id
+ n.visible = false
+ n.save_with_history!
+ end
+
+ self.changeset_id = changeset_id
+ self.tags = []
+ self.nds = []
+ self.visible = false
+ self.save_with_history!
+ end
+
+ # Find nodes that belong to this way only
+ def unshared_node_ids
+ node_ids = self.nodes.collect { |node| node.id }
+
+ unless node_ids.empty?
+ way_nodes = WayNode.find(:all, :conditions => "node_id in (#{node_ids.join(',')}) and id != #{self.id}")
+ node_ids = node_ids - way_nodes.collect { |way_node| way_node.node_id }
+ end
+
+ return node_ids
+ end
+
+ # Temporary method to match interface to nodes
+ def tags_as_hash
+ return self.tags
+ end
+
+ ##
+ # if any referenced nodes are placeholder IDs (i.e: are negative) then
+ # this calling this method will fix them using the map from placeholders
+ # to IDs +id_map+.
+ def fix_placeholders!(id_map)
+ self.nds.map! do |node_id|
+ if node_id < 0
+ new_id = id_map[:node][node_id]
+ raise "invalid placeholder for #{node_id.inspect}: #{new_id.inspect}" if new_id.nil?
+ new_id
+ else
+ node_id
+ end
+ end
+ end
+
+ private
+
+ def save_with_history!
+ t = Time.now
+
+ # update the bounding box, but don't save it as the controller knows the
+ # lifetime of the change better. note that this has to be done both before
+ # and after the save, so that nodes from both versions are included in the
+ # bbox.
+ changeset.update_bbox!(bbox) unless nodes.empty?
+
+ Way.transaction do
+ self.version += 1
+ self.timestamp = t
+ self.save!
+
+ tags = self.tags
+ WayTag.delete_all(['id = ?', self.id])
+ tags.each do |k,v|
+ tag = WayTag.new
+ tag.k = k
+ tag.v = v
+ tag.id = self.id
+ tag.save!
+ end
+
+ nds = self.nds
+ WayNode.delete_all(['id = ?', self.id])
+ sequence = 1
+ nds.each do |n|
+ nd = WayNode.new
+ nd.id = [self.id, sequence]
+ nd.node_id = n
+ nd.save!
+ sequence += 1
+ end
+
+ old_way = OldWay.from_way(self)
+ old_way.timestamp = t
+ old_way.save_with_dependencies!
+
+ # update and commit the bounding box, now that way nodes
+ # have been updated and we're in a transaction.
+ changeset.update_bbox!(bbox) unless nodes.empty?
+
+ # tell the changeset we updated one element only
+ changeset.add_changes! 1
+
+ changeset.save!
+ end
+ end
+