+
+ ##
+ # 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
+