class ActionView::PathResolver

def extract_handler_and_format_and_variant(path, default_formats)

to the resolver.
from the path, or the handler, we should return the array of formats given
Extract handler, formats and variant from path. If a format cannot be found neither 
def extract_handler_and_format_and_variant(path, default_formats)
  pieces = File.basename(path).split(".")
  pieces.shift
  extension = pieces.pop
  unless extension
    ActiveSupport::Deprecation.warn(<<-MSG.squish)
      The file #{path} did not specify a template handler. The default is
      currently ERB, but will change to RAW in the future.
    MSG
  end
  handler = Template.handler_for_extension(extension)
  format, variant = pieces.last.split(EXTENSIONS[:variants], 2) if pieces.last
  format  &&= Template::Types[format]
  [handler, format, variant]
end