Contents

#
#--
#
# $Id: treewalker.rb 531 2006-11-17 17:56:14Z thomas $
#
# webgen: template based static website generator
# Copyright (C) 2004 Thomas Leitner
#
# This program is free software; you can redistribute it and/or modify it under the terms of the GNU
# General Public License as published by the Free Software Foundation; either version 2 of the
# License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
# even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License along with this program; if not,
# write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#
#++
#


# All plugins which count as "tree walkers" should be put into this module.
module TreeWalkers

  # This is the main class for tree walkers. A tree walker plugin can register itself with this class
  # so that it is called when the main class' #execute method is called.
  class TreeWalker < Webgen::Plugin

    infos( :author => Webgen::AUTHOR,
           :summary => "Super plugin for traversing the node tree"
           )

    # Walks the +tree+ for the +walker+ in the +direction+, either +:forward+ or +:backward+.
    def execute( tree, walker, direction = :forward )
      walk_tree( tree, walker, 0, direction )
    end

    #######
    private
    #######

    # Walks the tree and calls the plugin +walker+ for each and every node.
    def walk_tree( node, walker, level, direction = :forward )
      walker.call( node, level ) if direction == :forward
      node.each do |child|
        walk_tree( child, walker, level + 1, direction )
      end
      walker.call( node, level ) if direction == :backward
    end

  end

end

Version data entries

2 entries across 2 versions & 1 rubygems

Version	Path
webgen-0.4.0	lib/webgen/plugins/miscplugins/treewalker.rb
webgen-0.4.1	lib/webgen/plugins/miscplugins/treewalker.rb