webgen users - Jun 2009 - Subclassing for tags

First of all, thanks for webgen. It''s been an invaluable tool for
doing static sites. I was a bit overwhelmed by what needed to be done
in order to subclass tag classes. The Webgen::Tag::Base is somewhat
coupled to a single class and subclasses need to override param() and
a couple other base functions to do correct resolution on their
superclass''s tag parameters. So, I tried to code up a simple solution
that shouldn''t break the current tags (but I haven''t tested it
on the
Webgen base yet), but I''m wondering what you all think about the
current situation of tag parameters and if there''s any plans to change
it.

Here''s what I came up with along with a simple example:


module SAD
  module Tag
    module Base
      include Webgen::Tag::Base

      private

      # The base part of the configuration name. This is the class
name without the Webgen module
      # downcased and all "::" substituted with "." (e.g.
Webgen::Tag::Menu -> tag.menu). By overriding
      # this method one can provide a different way of specifying the
base part of the configuration
      # name.
      def tag_config_base(c=self.class)
        c.name.gsub(''::'',
''.'').gsub(/^Webgen\./, '''').downcase
      end

      # The bases of a tag. This returns the tag_config_base name of
the current class and all it''s
      # superclasses.
      def tag_config_bases
        c = self.class
        bases = []
        until c == Object
          bases << tag_config_base(c)
          c = c.superclass
        end
          return bases
      end
      # Return the list of all parameters for the tag class. All
configuration options starting with
      # +tag_config_base+ are used.
      def tag_params_list
        param_list = []
        #This can be simplified if there''s no duplicate keys in
config?
        tag_config_bases.each do |base|
          param_list.concat website.config.data.keys.select { |key|
key =~ /^#{base}/ }
        end
        param_list
      end

      # Return a valid parameter hash taking values from +config+
which has to be a Hash.
      def create_from_hash(config, params, node)
        result = {}
        config.each do |key, value|
          found = false
          if params.include?(key)
            result[key] = value
            found = true
          else
            tag_config_bases.each do |base|
              if params.include?(base + ''.'' + key)
                result[base + ''.'' + key] = value
                found = true
              end
            end
          end
          unless found
            log(:warn) { "Invalid parameter ''#{key}'' for
tag ''#
{self.class.name}'' in <#{node.absolute_lcn}>" }
          end
        end
        result
      end


    end
    class CustomMenu < Webgen::Tag::Menu

      include Base

      # Create the not nested HTML menu of the +tree+ using the
provided +context+.
      def create_output_not_nested(context, tree, level = 1)
        submenu = ''''
        out = "<div id=\"top-nav-menu\">"
        tree.children.each do |child|
          submenu << (child.children.length > 0 ?
create_output_not_nested(context, child, level + 1) : '''')
          style, link = menu_item_details(context.dest_node,
child.node, context.content_node.lang, level)

          out << "#{link}"
        end
        out << "</div>"
        out << submenu
        out
      end
    end
  end
end
Webgen::WebsiteAccess.website.config[''contentprocessor.tags.map'']
[''custommenu''] = ''SAD::Tag::CustomMenu''