class ActionView::Template::Handlers::ERB

def self.handles_encoding?
  true
end

def compile(template)
  if template.source.encoding_aware?
    # First, convert to BINARY, so in case the encoding is
    # wrong, we can still find an encoding tag
    # (<%# encoding %>) inside the String using a regular
    # expression
    template_source = template.source.dup.force_encoding("BINARY")
    erb = template_source.gsub(ENCODING_TAG, '')
    encoding = $2
    erb.force_encoding valid_encoding(template.source.dup, encoding)
    # Always make sure we return a String in the default_internal
    erb.encode!
  else
    erb = template.source.dup
  end
  self.class.erb_implementation.new(
    erb,
    :trim => (self.class.erb_trim_mode == "-")
  ).src
end

def valid_encoding(string, encoding)
  # If a magic encoding comment was found, tag the
  # String with this encoding. This is for a case
  # where the original String was assumed to be,
  # for instance, UTF-8, but a magic comment
  # proved otherwise
  string.force_encoding(encoding) if encoding
  # If the String is valid, return the encoding we found
  return string.encoding if string.valid_encoding?
  # Otherwise, raise an exception
  raise WrongEncodingError.new(string, string.encoding)
end