Among other things, this method is responsible for properly setting the
encoding of the source.
Until this point, we assume that the source is BINARY data. If no
additional information is supplied, we assume the encoding is the same as
Encoding.default_external.
The user can also specify the encoding via a comment on the first line of
the template (# encoding: NAME-OF-ENCODING). This will work with any
template engine, as we process out the encoding comment before passing the
source on to the template
engine, leaving a blank line in its stead.
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.
# File actionpack/lib/action_view/template.rb, line 218
def compile(view, mod) #:nodoc:
method_name = self.method_name
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 = magic_encoding = $1
else
encoding = Encoding.default_external
end
# Tag the source with the default external encoding
# or the encoding specified in the file
source.force_encoding(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!
# Otherwise, since the String is invalid in the encoding
# specified, raise an exception
else
raise WrongEncodingError.new(source, encoding)
end
end
code = @handler.call(self)
# Make sure that the resulting String to be evalled is in the
# encoding of the code
source = def #{method_name}(local_assigns, output_buffer) _old_virtual_path, @virtual_path = @virtual_path, #{@virtual_path.inspect};_old_output_buffer = @output_buffer;#{locals_code};#{code} ensure @virtual_path, @output_buffer = _old_virtual_path, _old_output_buffer end
if source.encoding_aware?
# 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. This is for handlers
# that handle encoding but screw up
unless source.valid_encoding?
raise WrongEncodingError.new(@source, Encoding.default_internal)
end
end
begin
mod.module_eval(source, identifier, 0)
ObjectSpace.define_finalizer(self, Finalizer[method_name, mod])
rescue Exception => e # errors from template code
if logger = (view && view.logger)
logger.debug "ERROR: compiling #{method_name} RAISED #{e}"
logger.debug "Function body: #{source}"
logger.debug "Backtrace: #{e.backtrace.join("\n")}"
end
raise ActionView::Template::Error.new(self, {}, e)
end
end
