1 files changed, 67 insertions, 0 deletions
diff --git a/actionpack/lib/action_view/helpers/asset_tag_helpers/helper_methods.rb b/actionpack/lib/action_view/helpers/asset_tag_helpers/helper_methods.rb
new file mode 100644
index 0000000000..348e33d535
--- /dev/null
+++ b/actionpack/lib/action_view/helpers/asset_tag_helpers/helper_methods.rb
@@ -0,0 +1,67 @@
+require 'active_support/concern'
+require 'active_support/inflector'
+
+module ActionView
+  module Helpers
+    module AssetTagHelper
+
+      module HelperMethods
+        private
+        def asset_path(asset_type, extension = nil)
+          define_method("#{asset_type}_path") do |source|
+            compute_public_path(source, asset_type.to_s.pluralize, extension)
+          end
+          alias_method :"path_to_#{asset_type}", :"#{asset_type}_path" # aliased to avoid conflicts with a *_path named route
+        end
+      end
+
+      module SharedHelpers
+        def determine_source(source, collection)
+          case source
+          when Symbol
+            collection[source] || raise(ArgumentError, "No expansion found for #{source.inspect}")
+          else
+            source
+          end
+        end
+
+        def join_asset_file_contents(paths)
+          paths.collect { |path| File.read(asset_file_path!(path, true)) }.join("\n\n")
+        end
+
+        def write_asset_file_contents(joined_asset_path, asset_paths)
+          FileUtils.mkdir_p(File.dirname(joined_asset_path))
+          File.atomic_write(joined_asset_path) { |cache| cache.write(join_asset_file_contents(asset_paths)) }
+
+          # Set mtime to the latest of the combined files to allow for
+          # consistent ETag without a shared filesystem.
+          mt = asset_paths.map { |p| File.mtime(asset_file_path(p)) }.max
+          File.utime(mt, mt, joined_asset_path)
+        end
+
+        def asset_file_path(path)
+          File.join(config.assets_dir, path.split('?').first)
+        end
+
+        def asset_file_path!(path, error_if_file_is_uri = false)
+          if is_uri?(path)
+            raise(Errno::ENOENT, "Asset file #{path} is uri and cannot be merged into single file") if error_if_file_is_uri
+          else
+            absolute_path = asset_file_path(path)
+            raise(Errno::ENOENT, "Asset file not found at '#{absolute_path}'" ) unless File.exist?(absolute_path)
+            return absolute_path
+          end
+        end
+
+        def collect_asset_files(*path)
+          dir = path.first
+
+          Dir[File.join(*path.compact)].collect do |file|
+            file[-(file.size - dir.size - 1)..-1].sub(/\.\w+$/, '')
+          end.sort
+        end
+      end
+
+    end
+  end
+end
+\ No newline at end of file