From 0078df6b54e595421bb486613f7bc3693250b592 Mon Sep 17 00:00:00 2001 From: wycats Date: Sun, 30 May 2010 11:07:34 +0200 Subject: Update template to allow handlers to more cleanly handle encodings (ht: nex3) --- actionpack/lib/action_view/template.rb | 77 +++++++++++++++++----------------- 1 file changed, 39 insertions(+), 38 deletions(-) (limited to 'actionpack/lib/action_view/template.rb') diff --git a/actionpack/lib/action_view/template.rb b/actionpack/lib/action_view/template.rb index 5d8ac6b115..53ad24fdc6 100644 --- a/actionpack/lib/action_view/template.rb +++ b/actionpack/lib/action_view/template.rb @@ -22,6 +22,10 @@ module ActionView # users will see diamonds with question marks in them in # the browser. # + # For the rest of this documentation, when we say "UTF-8", + # we mean "UTF-8 or whatever the default_internal encoding + # is set to". By default, it will be UTF-8. + # # To mitigate this problem, we use a few strategies: # 1. If the source is not valid UTF-8, we raise an exception # when the template is compiled to alert the user @@ -32,8 +36,7 @@ module ActionView # to the resulting compiled source returned by the # template handler. # 3. In all cases, we transcode the resulting String to - # the default_internal encoding (which defaults - # to UTF-8). + # the UTF-8. # # This means that other parts of Rails can always assume # that templates are encoded in UTF-8, even if the original @@ -60,14 +63,14 @@ module ActionView # # If you want to provide an alternate mechanism for # specifying encodings (like ERB does via <%# encoding: ... %>), - # you may indicate that you are willing to accept - # BINARY data by implementing self.accepts_binary? + # you may indicate that you will handle encodings yourself + # by implementing self.handles_encoding? # on your handler. # - # If you do, Rails will not raise an exception if - # the template's encoding could not be determined, - # assuming that you have another mechanism for - # making the determination. + # If you do, Rails will not try to encode the String + # into the default_internal, passing you the unaltered + # bytes tagged with the assumed encoding (from + # default_external). # # In this case, make sure you return a String from # your handler encoded in the default_internal. Since @@ -171,7 +174,12 @@ module ActionView # before passing the source on to the template engine, leaving a # blank line in its stead. # - # Note that after we figure out the correct encoding, we then + # If the template engine handles encodings, we send the encoded + # String to the engine without further processing. This allows + # the template engine to support additional mechanisms for + # specifying the encoding. For instance, ERB supports <%# encoding: %> + # + # Otherwise, after we figure out the correct encoding, we then # encode the source into Encoding.default_internal. In general, # this means that templates will be UTF-8 inside of Rails, # regardless of the original source encoding. @@ -182,8 +190,11 @@ module ActionView locals_code = locals.keys.map! { |key| "#{key} = local_assigns[:#{key}];" }.join if source.encoding_aware? + # Look for # encoding: *. If we find one, we'll encode the + # String in that encoding, otherwise, we'll use the + # default external encoding. if source.sub!(/\A#{ENCODING_FLAG}/, '') - encoding = $1 + encoding = magic_encoding = $1 else encoding = Encoding.default_external end @@ -192,34 +203,28 @@ module ActionView # or the encoding specified in the file source.force_encoding(encoding) - # If the original encoding is BINARY, the actual - # encoding is either stored out-of-band (such as - # in ERB <%# %> style magic comments) or missing. - # This is also true if the original encoding is - # something other than BINARY, but it's invalid. - if source.encoding != Encoding::BINARY && source.valid_encoding? + # If the user didn't specify an encoding, and the handler + # handles encodings, we simply pass the String as is to + # the handler (with the default_external tag) + if !magic_encoding && @handler.respond_to?(:handles_encoding?) && @handler.handles_encoding? + source + # Otherwise, if the String is valid in the encoding, + # encode immediately to default_internal. This means + # that if a handler doesn't handle encodings, it will + # always get Strings in the default_internal + elsif source.valid_encoding? source.encode! - # If the assumed encoding is incorrect, check to - # see whether the handler accepts BINARY. If it - # does, it has another mechanism for determining - # the true encoding of the String. - elsif @handler.respond_to?(:accepts_binary?) && @handler.accepts_binary? - source.force_encoding(Encoding::BINARY) - # If the handler does not accept BINARY, the - # assumed encoding (either the default_external, - # or the explicit encoding specified by the user) - # is incorrect. We raise an exception here. + # Otherwise, since the String is invalid in the encoding + # specified, raise an exception else raise WrongEncodingError.new(source, encoding) end - - # Don't validate the encoding yet -- the handler - # may treat the String as raw bytes and extract - # the encoding some other way end code = @handler.call(self) + # Make sure that the resulting String to be evalled is in the + # encoding of the code source = <<-end_src def #{method_name}(local_assigns) _old_virtual_path, @_virtual_path = @_virtual_path, #{@virtual_path.inspect};_old_output_buffer = @output_buffer;#{locals_code};#{code} @@ -229,20 +234,16 @@ module ActionView end_src if source.encoding_aware? - # Handlers should return their source Strings in either the - # default_internal or BINARY. If the handler returns a BINARY - # String, we assume its encoding is the one we determined - # earlier, and encode the resulting source in the default_internal. - if source.encoding == Encoding::BINARY - source.force_encoding(Encoding.default_internal) - end + # Make sure the source is in the encoding of the returned code + source.force_encoding(code.encoding) # In case we get back a String from a handler that is not in # BINARY or the default_internal, encode it to the default_internal source.encode! # Now, validate that the source we got back from the template - # handler is valid in the default_internal + # handler is valid in the default_internal. This is for handlers + # that handle encoding but screw up unless source.valid_encoding? raise WrongEncodingError.new(@source, Encoding.default_internal) end -- cgit v1.2.3