require 'activesupport' require 'fastercsv' require 'comma/extractors' class Array def to_comma(style = :default) FasterCSV.generate do |csv| csv << first.to_comma_headers(style) each do |object| csv << object.to_comma(style) end end end end class Object class_inheritable_accessor :comma_formats def self.comma(style = :default, &block) (self.comma_formats ||= {})[style] = block end def to_comma(style = :default) raise "No comma format for class #{self.class} defined for style #{style}" unless self.comma_formats and self.comma_formats[style] Comma::DataExtractor.new(self, &self.comma_formats[style]).results end def to_comma_headers(style = :default) raise "No comma format for class #{self.class} defined for style #{style}" unless self.comma_formats and self.comma_formats[style] Comma::HeaderExtractor.new(self, &self.comma_formats[style]).results end end if defined?(ActionController) module RenderAsCSV def self.included(base) base.send :include, InstanceMethods base.alias_method_chain :render, :csv end module InstanceMethods def render_with_csv(options = nil, extra_options = {}, &block) return render_without_csv(options, extra_options, &block) unless options and options[:csv] send_data Array(options[:csv]).to_comma(options[:style] ||= :default) end end end ActionController::Base.send :include, RenderAsCSV end