Fun metaprogramming, blocks, and some tricks with Ruby (basically a quick replication of what builder gem does)

builder.rb

class Builder
  def initialize
		@tag_stack = []
	end

	def method_missing(name, *args, &blk)
		print " "*@tag_stack.size
		print "<#{name}" + attributes(args) + ">"
		@tag_stack.push name
		if block_given?
			puts
			instance_eval &blk
		else
			self
		end
		@tag_stack.pop
		print " "*@tag_stack.size
		puts "</#{name}>"
	end

	def attributes args
		if args.nil? || args[0].nil?
			""
		else
			h = args[0]
			" " + (h.keys.map{ |k| %Q[#{k}="#{h[k]}"] }).join(" ")
		end
	end
 end

Builder.new.html do 
	head
	body { div({"id" => "family", "class" => "child"}){div} }
end