make action and fragment caching of rails 3.0.9 compatible with content_for

gistfile1.rb

module ActionController

  class Metal
    attr_internal :cached_content_for
  end

  module Caching
    module Actions
      def _save_fragment(name, options)
        return unless caching_allowed?

        content = response_body
        content = content.join if content.is_a?(Array)
        content = cached_content_for.merge(:layout => content) if cached_content_for.is_a?(Hash)

        write_fragment(name, content, options)
      end
    end

    module Fragments
      def write_fragment_with_content_to_cache(key, content, options = nil)
        return_content = write_fragment_without_content_to_cache(key, content, options)
        return_content.is_a?(Hash) && return_content.key?(:layout) ? return_content[:layout] : return_content
      end

      def read_fragment_with_content_to_cache(key, options = nil)
        result = read_fragment_without_content_to_cache(key, options)
        if result.is_a?(Hash) && result.key?(:layout)
          result = result.dup if result.frozen?
          fragment = result.delete(:layout)
          self.cached_content_for = (self.cached_content_for || {}).merge(result){|_, v1, v2| v1 + v2 }
          result = fragment
        end

        result.respond_to?(:html_safe) ? result.html_safe : result
      end

      alias_method_chain :write_fragment, :content_to_cache
      alias_method_chain :read_fragment, :content_to_cache
    end
  end
end

module ActionView
  module Rendering
    # Added to support implementation of action caching
    def _render_template_with_cached_content_for(template, layout = nil, options = {})
      if controller.respond_to?('caching_allowed?') && controller.caching_allowed?
        if controller.cached_content_for.is_a?(Hash)
          controller.cached_content_for.each { |k, v| content_for(k, v) }
          controller.cached_content_for = {}
        end
        return_value = _render_template_without_cached_content_for(template, layout, options)
      elsif
        return_value = _render_template_without_cached_content_for(template, layout, options)
      end
      return_value
    end

    alias_method_chain :_render_template, :cached_content_for
  end

  module Helpers
    module CaptureHelper
      # Added to support implementation of fragment caching
      def cache_with_content_for #:nodoc:#
        @_subset_content_for ||= []
        @_subset_content_for.push(Hash.new { |h,k| h[k] = ActiveSupport::SafeBuffer.new })
        @cache_level = @_subset_content_for.size
        yield
      ensure
        @_subset_content_for.pop
        @cache_level = @_subset_content_for.size
      end

      def cache_level
        @cache_level ||= 1
        @cache_level - 1
      end

      # Added to support implementation of action caching
      def content_to_cache #:nodoc:#
        cache_this = (@_subset_content_for && @_subset_content_for[cache_level]) || @_content_for.except(:layout)
        cache_this.dup.tap {|h| h.default = nil }
      end

      # Overwrite content_for to support fragment caching
      def content_for(name, content = nil, &block)
        content = capture(&block) if block_given?
        @_content_for[name] << content if content
        if content && @_subset_content_for && @_subset_content_for[cache_level]
          @_subset_content_for[cache_level][name] << content

          # также нужно передать этот контент всем родительским кеш-блокам
          (cache_level - 1).downto(0) do |i|
            @_subset_content_for[i][name] << content
          end
        end

        @_content_for[name] unless content
      end
    end

    module CacheHelper
      def fragment_for(name = {}, options = nil, &block) #:nodoc:
        if controller.fragment_exist?(name, options)
          fragment = controller.read_fragment(name, options)
          if controller.cached_content_for.is_a?(Hash)
            controller.cached_content_for.each { |k, v| content_for(k, v) }
            controller.cached_content_for = {}
          end
          fragment
        else
          pos = output_buffer.length
          hash_to_cache = nil
          cache_with_content_for do
            yield
            
            if output_buffer.is_a?(ActionView::OutputBuffer)
              safe_output_buffer = output_buffer.to_str
              fragment = safe_output_buffer.slice!(pos..-1)
              self.output_buffer = ActionView::OutputBuffer.new(safe_output_buffer)
            else
              fragment = output_buffer.slice!(pos..-1)
            end

            hash_to_cache = {:layout => fragment}.merge(content_to_cache)
          end
          controller.write_fragment(name, hash_to_cache, options)
        end
      end
    end
  end
end