gistfile1.rb

module CategoriesTags
	extend Nanoc::Memoization

	def all_categories
		categories = []
		posts.each do |post|
			next if post[:categories].nil?
			categories << post[:categories]
		end
		categories.uniq
	end
	memoize :all_categories

	def has_category?(category, post)
		if post[:categories].nil?
			false
		else
			post[:categories].include?(category)
		end
	end

	def news_with_category(category, news=sorted_posts)
		news.select { |post| has_category?(category, post) }
	end
	memoize :news_with_category

	def news_by_category(news=posts)
		categories = []
		all_categories.each do |category|
			categories << [category, news_with_category(category)]
		end
		categories
	end
	memoize :news_by_category


end