Module: Mail::Encodings

Extended by:
Utilities
Includes:
Patterns
Defined in:
lib/mail/encodings.rb,
lib/mail/encodings/7bit.rb,
lib/mail/encodings/8bit.rb,
lib/mail/encodings/base64.rb,
lib/mail/encodings/binary.rb,
lib/mail/encodings/quoted_printable.rb,
lib/mail/encodings/transfer_encoding.rb

Defined Under Namespace

Classes: Base64, Binary, EightBit, QuotedPrintable, SevenBit, TransferEncoding

Constant Summary

Constants included from Patterns

Patterns::ATOM_UNSAFE, Patterns::CONTROL_CHAR, Patterns::CRLF, Patterns::FIELD_BODY, Patterns::FIELD_LINE, Patterns::FIELD_NAME, Patterns::FWS, Patterns::HEADER_LINE, Patterns::PHRASE_UNSAFE, Patterns::QP_SAFE, Patterns::QP_UNSAFE, Patterns::TEXT, Patterns::TOKEN_UNSAFE, Patterns::WSP

Class Method Summary collapse

Methods included from Utilities

atom_safe?, bracket, capitalize_field, constantize, dasherize, dquote, escape_paren, map_lines, map_with_index, match_to_s, paren, quote_atom, quote_phrase, quote_token, token_safe?, unbracket, underscoreize, unparen, unquote, uri_escape, uri_parser, uri_unescape

Class Method Details

.address_encode(address, charset = 'utf-8') ⇒ Object


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# File 'lib/mail/encodings.rb', line 176

def Encodings.address_encode(address, charset = 'utf-8')
  if address.is_a?(Array)
    # loop back through for each element
    address.compact.map { |a| Encodings.address_encode(a, charset) }.join(", ")
  else
    # find any word boundary that is not ascii and encode it
    encode_non_usascii(address, charset) if address
  end
end

.b_value_encode(encoded_str, encoding = nil) ⇒ Object

Encode a string with Base64 Encoding and returns it ready to be inserted as a value for a field, that is, in the =?<charset>?B?<string>?= format

Example:

Encodings.b_value_encode('This is あ string', 'UTF-8')
#=> "=?UTF-8?B?VGhpcyBpcyDjgYIgc3RyaW5n?="

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# File 'lib/mail/encodings.rb', line 213

def Encodings.b_value_encode(encoded_str, encoding = nil)
  return encoded_str if encoded_str.to_s.ascii_only?
  string, encoding = RubyVer.b_value_encode(encoded_str, encoding)
  map_lines(string) do |str|
    "=?#{encoding}?B?#{str.chomp}?="
  end.join(" ")
end

.decode_encode(str, output_type) ⇒ Object

Decodes or encodes a string as needed for either Base64 or QP encoding types in the =?<encoding>??<string>?=“ format.

The output type needs to be :decode to decode the input string or :encode to encode the input string. The character set used for encoding will either be the value of $KCODE for Ruby < 1.9 or the encoding on the string passed in.

On encoding, will only send out Base64 encoded strings.


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# File 'lib/mail/encodings.rb', line 98

def Encodings.decode_encode(str, output_type)
  case
  when output_type == :decode
    Encodings.value_decode(str)
  else
    if str.ascii_only?
      str
    else
      Encodings.b_value_encode(str, find_encoding(str))
    end
  end
end

.defined?(str) ⇒ Boolean

Is the encoding we want defined?

Example:

Encodings.defined?(:base64) #=> true

Returns:

  • (Boolean)

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# File 'lib/mail/encodings.rb', line 29

def Encodings.defined?( str )
  @transfer_encodings.include? get_name(str)
end

.encode_non_usascii(address, charset) ⇒ Object


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# File 'lib/mail/encodings.rb', line 186

def Encodings.encode_non_usascii(address, charset)
  return address if address.ascii_only? or charset.nil?
  us_ascii = %Q{\x00-\x7f}
  # Encode any non usascii strings embedded inside of quotes
  address = address.gsub(/(".*?[^#{us_ascii}].*?")/) { |s| Encodings.b_value_encode(unquote(s), charset) }
  # Then loop through all remaining items and encode as needed
  tokens = address.split(/\s/)
  map_with_index(tokens) do |word, i|
    if word.ascii_only?
      word
    else
      previous_non_ascii = tokens[i-1] && !tokens[i-1].ascii_only?
      if previous_non_ascii
        word = " #{word}"
      end
      Encodings.b_value_encode(word, charset)
    end
  end.join(' ')
end

.get_allObject


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# File 'lib/mail/encodings.rb', line 45

def Encodings.get_all
  @transfer_encodings.values
end

.get_encoding(str) ⇒ Object

Gets a defined encoding type, QuotedPrintable or Base64 for now.

Each encoding needs to be defined as a Mail::Encodings::ClassName for this to work, allows us to add other encodings in the future.

Example:

Encodings.get_encoding(:base64) #=> Mail::Encodings::Base64

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# File 'lib/mail/encodings.rb', line 41

def Encodings.get_encoding( str )
  @transfer_encodings[get_name(str)]
end

.get_name(enc) ⇒ Object


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# File 'lib/mail/encodings.rb', line 49

def Encodings.get_name(enc)
  enc = enc.to_s.gsub("-", "_").downcase
end

.param_decode(str, encoding) ⇒ Object

Decodes a parameter value using URI Escaping.

Example:

Mail::Encodings.param_decode("This%20is%20fun", 'us-ascii') #=> "This is fun"

str = Mail::Encodings.param_decode("This%20is%20fun", 'iso-8559-1')
str.encoding #=> 'ISO-8859-1'      ## Only on Ruby 1.9
str #=> "This is fun"

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# File 'lib/mail/encodings.rb', line 86

def Encodings.param_decode(str, encoding)
  RubyVer.param_decode(str, encoding)
end

.param_encode(str) ⇒ Object

Encodes a parameter value using URI Escaping, note the language field 'en' can be set using Mail::Configuration, like so:

Mail.defaults.do
  param_encode_language 'jp'
end

The character set used for encoding will either be the value of $KCODE for Ruby < 1.9 or the encoding on the string passed in.

Example:

Mail::Encodings.param_encode("This is fun") #=> "us-ascii'en'This%20is%20fun"

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# File 'lib/mail/encodings.rb', line 66

def Encodings.param_encode(str)
  case
  when str.ascii_only? && str =~ TOKEN_UNSAFE
    %Q{"#{str}"}
  when str.ascii_only?
    str
  else
    RubyVer.param_encode(str)
  end
end

.q_value_encode(encoded_str, encoding = nil) ⇒ Object

Encode a string with Quoted-Printable Encoding and returns it ready to be inserted as a value for a field, that is, in the =?<charset>?Q?<string>?= format

Example:

Encodings.q_value_encode('This is あ string', 'UTF-8')
#=> "=?UTF-8?Q?This_is_=E3=81=82_string?="

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# File 'lib/mail/encodings.rb', line 228

def Encodings.q_value_encode(encoded_str, encoding = nil)
  return encoded_str if encoded_str.to_s.ascii_only?
  string, encoding = RubyVer.q_value_encode(encoded_str, encoding)
  string.gsub!("=\r\n", '') # We already have limited the string to the length we want
  map_lines(string) do |str|
    "=?#{encoding}?Q?#{str.chomp.gsub(/ /, '_')}?="
  end.join(" ")
end

.register(name, cls) ⇒ Object

Register transfer encoding

Example

Encodings.register “base64”, Mail::Encodings::Base64


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# File 'lib/mail/encodings.rb', line 20

def Encodings.register(name, cls)
    @transfer_encodings[get_name(name)] = cls
end

.unquote_and_convert_to(str, to_encoding) ⇒ Object

Takes an encoded string of the format =?<encoding>??<string>?=


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# File 'lib/mail/encodings.rb', line 149

def Encodings.unquote_and_convert_to(str, to_encoding)
  output = value_decode( str ).to_s # output is already converted to UTF-8
  
  if 'utf8' == to_encoding.to_s.downcase.gsub("-", "")
    output
  elsif to_encoding
    begin
      if RUBY_VERSION >= '1.9'
        output.encode(to_encoding)
      else
        require 'iconv'
        Iconv.iconv(to_encoding, 'UTF-8', output).first 
      end
    rescue Iconv::IllegalSequence, Iconv::InvalidEncoding, Errno::EINVAL
      # the 'from' parameter specifies a charset other than what the text
      # actually is...not much we can do in this case but just return the
      # unconverted text.
      #
      # Ditto if either parameter represents an unknown charset, like
      # X-UNKNOWN.
      output
    end
  else
    output
  end
end

.value_decode(str) ⇒ Object

Decodes a given string as Base64 or Quoted Printable, depending on what type it is.

String has to be of the format =?<encoding>??<string>?=


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# File 'lib/mail/encodings.rb', line 115

def Encodings.value_decode(str)
  # Optimization: If there's no encoded-words in the string, just return it
  return str unless str.index("=?")

  str = str.gsub(/\?=(\s*)=\?/, '?==?') # Remove whitespaces between 'encoded-word's

  # Split on white-space boundaries with capture, so we capture the white-space as well
  str.split(/([ \t])/).map do |text|
    if text.index('=?') .nil?
      text
    else
      # Join QP encoded-words that are adjacent to avoid decoding partial chars
      text.gsub!(/\?\=\=\?.+?\?[Qq]\?/m, '') if text =~ /\?==\?/

      # Search for occurences of quoted strings or plain strings
      text.scan(/(                                  # Group around entire regex to include it in matches
                   \=\?[^?]+\?([QB])\?[^?]+?\?\=  # Quoted String with subgroup for encoding method
                   |                                # or
                   .+?(?=\=\?|$)                    # Plain String
                 )/xmi).map do |matches|
        string, method = *matches
        if    method == 'b' || method == 'B'
          b_value_decode(string)
        elsif method == 'q' || method == 'Q'
          q_value_decode(string)
        else
          string
        end
      end
    end
  end.join("")
end