nanoc_menu.rb

include Nanoc3::Helpers::LinkTo

# COPIED FROM http://github.com/ddfreyne/nanoc/blob/master/lib/nanoc3/base/compilation/compiler_dsl.rb
# Converts the given identifier, which can contain the '*' or '+'
# wildcard characters, matching zero or more resp. one or more
# characters, to a regex. For example, 'foo/*/bar' is transformed
# into /^foo\/(.*?)\/bar$/ and 'foo+' is transformed into /^foo(.+?)/.
def identifier_to_regex(identifier)
  if identifier.is_a? String
    # Add leading/trailing slashes if necessary
    new_identifier = identifier.dup
    new_identifier[/^/] = '/' if identifier[0,1] != '/'
    new_identifier[/$/] = '/' unless [ '*', '/' ].include?(identifier[-1,1])

    /^#{new_identifier.gsub('*', '(.*?)').gsub('+', '(.+?)')}$/
  else
    identifier
  end
end

def menu(parent, options={})
  if parent.children.empty?
    ''
  else
    children = parent.children
    # exclude
    if options[:exclude]
      exclude_regex = identifier_to_regex options[:exclude]
      children.reject! { |child| (child.identifier =~ exclude_regex) != nil }
    end
    # sort
    if options[:sort]
      children.sort! do |a, b|
        a[options[:sort]].to_i <=> b[options[:sort]].to_i
      end
    end
    # reverse
    if options[:descending]
      children.reverse!
    end

    childoptions = options.reject { | key, value | key == :display_parent }
    list = children.inject('') do |memo, child|
      memo + "<li>#{link_to_unless_current child[:title], child}#{menu child, childoptions}</li>"
    end
    # display_parent
    if options[:display_parent]
      list = "<li>#{link_to_unless_current parent[:title], parent}</li>" + list
    end
    "<ul>#{list}</ul>"
  end
end