Module: RDoc::Encoding

Relationships & Source Files
Defined in:	lib/rdoc/encoding.rb

Overview

This class is a wrapper around File IO and Encoding that helps RDoc load files and convert them to the correct encoding.

Constant Summary

HEADER_REGEXP = Internal use only
# File 'lib/rdoc/encoding.rb', line 10

/^
  (?:
    \A\#!.*\n
    |
    ^\#\sfrozen[-_]string[-_]literal[=:].\n
    |
    ^\#[^\n]\b(?:en)?coding[=:]\s*(?<name>[^\s;]).*\n
    |
    <\?xml[^?]*encoding=(?<quote>["'])(?<name>.*?)\k<quote>.*\n
  )+
/xi

Class Method Summary

.change_encoding(text, encoding)

Changes encoding based on encoding without converting and returns new string.
.detect_encoding(string)

Detects the encoding of string based on the magic comment.
.read_file(filename, encoding, force_transcode = false)

Reads the contents of filename and handles any encoding directives in the file.
.remove_magic_comment(string)

Removes magic comments and shebang.

Class Method Details

.change_encoding(text, encoding)

Changes encoding based on encoding without converting and returns new string

[ GitHub ]

# File 'lib/rdoc/encoding.rb', line 112


def self.change_encoding text, encoding
  if text.kind_of? RDoc::Comment
    text.encode! encoding
  else
    String.new text, encoding: encoding
  end
end

.detect_encoding(string)

Detects the encoding of string based on the magic comment

[ GitHub ]

# File 'lib/rdoc/encoding.rb', line 92


def self.detect_encoding string
  result = HEADER_REGEXP.match string
  name = result && result[:name]

  name ? Encoding.find(name) : nil
end

.read_file(filename, encoding, force_transcode = false)

Reads the contents of filename and handles any encoding directives in the file.

The content will be converted to the encoding. If the file cannot be converted a warning will be printed and nil will be returned.

If force_transcode is true the document will be transcoded and any unknown character in the target encoding will be replaced with ‘?’

[ GitHub ]

# File 'lib/rdoc/encoding.rb', line 32


def self.read_file filename, encoding, force_transcode = false
  content = File.open filename, "rb" do |f| f.read end
  content.gsub!("\r\n", "\n") if RUBY_PLATFORM =~ /mswin|mingw/

  utf8 = content.sub!(/\A\xef\xbb\xbf/, '')

  enc = RDoc::Encoding.detect_encoding content
  content = RDoc::Encoding.change_encoding content, enc if enc

  begin
    encoding ||= Encoding.default_external
    orig_encoding = content.encoding

    if not orig_encoding.ascii_compatible? then
      content = content.encode encoding
    elsif utf8 then
      content = RDoc::Encoding.change_encoding content, Encoding::UTF_8
      content = content.encode encoding
    else
      # assume the content is in our output encoding
      content = RDoc::Encoding.change_encoding content, encoding
    end

    unless content.valid_encoding? then
      # revert and try to transcode
      content = RDoc::Encoding.change_encoding content, orig_encoding
      content = content.encode encoding
    end

    unless content.valid_encoding? then
      warn "unable to convert #{filename} to #{encoding}, skipping"
      content = nil
    end
  rescue Encoding::InvalidByteSequenceError,
         Encoding::UndefinedConversionError => e
    if force_transcode then
      content = RDoc::Encoding.change_encoding content, orig_encoding
      content = content.encode(encoding,
                               :invalid => :replace,
                               :undef => :replace,
                               :replace => '?')
      return content
    else
      warn "unable to convert #{e.message} for #{filename}, skipping"
      return nil
    end
  end

  content
rescue ArgumentError => e
  raise unless e.message =~ /unknown encoding name - (.*)/
  warn "unknown encoding name \"#{$1}\" for #{filename}, skipping"
  nil
rescue Errno::EISDIR, Errno::ENOENT
  nil
end

.remove_magic_comment(string)

Removes magic comments and shebang

[ GitHub ]

# File 'lib/rdoc/encoding.rb', line 102


def self.remove_magic_comment string
  string.sub HEADER_REGEXP do |s|
    s.gsub(/[^\n]/, '')
  end
end