Redmine

# Adds asset_id parameters to assets like Rails 3 to invalidate caches in browser

module ActionView

  module Helpers

    module AssetUrlHelper

      @@cache_asset_timestamps = Rails.env.production?

      @@asset_timestamps_cache = {}

      @@asset_timestamps_cache_guard = Mutex.new

      def asset_path_with_asset_id(source, options = {})

        asset_id = rails_asset_id(source, options)

        unless asset_id.blank?

          source += "?#{asset_id}"

        end

        asset_path(source, options)

      end

      alias :path_to_asset :asset_path_with_asset_id

      def rails_asset_id(source, options = {})

        if asset_id = ENV["RAILS_ASSET_ID"]

          asset_id

        else

          if @@cache_asset_timestamps && (asset_id = @@asset_timestamps_cache[source])

            asset_id

          else

            extname = compute_asset_extname(source, options)

            path = File.join(Rails.public_path, "#{source}#{extname}")

            exist = false

            if File.exist? path

              exist = true

            else

              path = File.join(Rails.public_path, compute_asset_path("#{source}#{extname}", options))

              if File.exist? path

                exist = true

              end

            end

            asset_id = exist ? File.mtime(path).to_i.to_s : ''

            if @@cache_asset_timestamps

              @@asset_timestamps_cache_guard.synchronize do

                @@asset_timestamps_cache[source] = asset_id

              end

            end

            asset_id

          end

        end

      end

    end

  end

end