+ def preconditions_ok?
+ return false if self.nds.empty?
+ if self.nds.length > APP_CONFIG['max_number_of_way_nodes']
+ raise OSM::APITooManyWayNodesError.new(self.nds.count, APP_CONFIG['max_number_of_way_nodes'])
+ end
+ self.nds.each do |n|
+ node = Node.find(:first, :conditions => ["id = ?", n])
+ unless node and node.visible
+ raise OSM::APIPreconditionFailedError.new("The node with id #{n} either does not exist, or is not visible")
+ end
+ end
+ return true
+ end
+
+ 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.new("You need to make sure that this way is not a member of a relation.")
+ else
+ self.changeset_id = new_way.changeset_id
+ self.tags = []
+ self.nds = []
+ self.visible = false
+ save_with_history!
+ end
+ end
+ end