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



178
179
180
181
182
183
184
185
186
# File 'lib/mail/encodings.rb', line 178

def Encodings.address_encode(address, charset = 'utf-8')
  if address.is_a?(Array)
    # loop back through for each element
    address.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)
  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?="


215
216
217
218
219
220
221
# File 'lib/mail/encodings.rb', line 215

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.



98
99
100
101
102
103
104
105
106
107
108
109
# 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)


29
30
31
# File 'lib/mail/encodings.rb', line 29

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

.encode_non_usascii(address, charset) ⇒ Object



188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
# File 'lib/mail/encodings.rb', line 188

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.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



45
46
47
# 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


41
42
43
# File 'lib/mail/encodings.rb', line 41

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

.get_name(enc) ⇒ Object



49
50
51
# 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"


86
87
88
# 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"


66
67
68
69
70
71
72
73
74
75
# 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?="


230
231
232
233
234
235
236
237
# File 'lib/mail/encodings.rb', line 230

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



20
21
22
# 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>?=



149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
# File 'lib/mail/encodings.rb', line 149

def Encodings.unquote_and_convert_to(str, to_encoding)
  original_encoding = split_encoding_from_string( str )

  output = value_decode( str ).to_s

  if original_encoding.to_s.downcase.gsub("-", "") == to_encoding.to_s.downcase.gsub("-", "")
    output
  elsif original_encoding && to_encoding
    begin
      if RUBY_VERSION >= '1.9'
        output.encode(to_encoding)
      else
        require 'iconv'
        Iconv.iconv(to_encoding, original_encoding, 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>?=



115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
# 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