module Mail::Encodings
Public Class Methods
# File lib/mail/encodings.rb, line 162 def Encodings.address_encode(address, charset = 'utf-8') if address.is_a?(Array) address.compact.map { |a| Encodings.address_encode(a, charset) }.join(", ") elsif address encode_non_usascii(address, charset) end end
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?="
# File lib/mail/encodings.rb, line 199 def Encodings.b_value_encode(string, encoding = nil) if string.to_s.ascii_only? string else Encodings.each_base64_chunk_byterange(string, 60).map do |chunk| str, encoding = Utilities.b_value_encode(chunk, encoding) "=?#{encoding}?B?#{str.chomp}?=" end.join(" ") end end
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 be the encoding on the string passed in.
On encoding, will only send out Base64
encoded strings.
# File lib/mail/encodings.rb, line 105 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, str.encoding) end end end
Is the encoding we want defined?
Example:
Encodings.defined?(:base64) #=> true
# File lib/mail/encodings.rb, line 29 def Encodings.defined?(name) @transfer_encodings.include? get_name(name) end
# File lib/mail/encodings.rb, line 170 def Encodings.encode_non_usascii(address, charset) return address if address.ascii_only? or charset.nil? # Encode all strings embedded inside of quotes address = address.gsub(/("[^"]*[^\/]")/) { |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 = i>0 && tokens[i-1] && !tokens[i-1].ascii_only? if previous_non_ascii #why are we adding an extra space here? word = " #{word}" end Encodings.b_value_encode(word, charset) end end.join(' ') end
# File lib/mail/encodings.rb, line 45 def Encodings.get_all @transfer_encodings.values end
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
# File lib/mail/encodings.rb, line 41 def Encodings.get_encoding(name) @transfer_encodings[get_name(name)] end
# File lib/mail/encodings.rb, line 49 def Encodings.get_name(name) underscoreize(name).downcase end
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"
# File lib/mail/encodings.rb, line 93 def Encodings.param_decode(str, encoding) Utilities.param_decode(str, encoding) end
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 be the encoding on the string passed in.
Example:
Mail::Encodings.param_encode("This is fun") #=> "us-ascii'en'This%20is%20fun"
# File lib/mail/encodings.rb, line 73 def Encodings.param_encode(str) case when str.ascii_only? && str =~ TOKEN_UNSAFE %Q{"#{str}"} when str.ascii_only? str else Utilities.param_encode(str) end end
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?="
# File lib/mail/encodings.rb, line 217 def Encodings.q_value_encode(encoded_str, encoding = nil) return encoded_str if encoded_str.to_s.ascii_only? string, encoding = Utilities.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 transfer encoding
Example
Encodings.register
“base64”, Mail::Encodings::Base64
# File lib/mail/encodings.rb, line 20 def Encodings.register(name, cls) @transfer_encodings[get_name(name)] = cls end
# File lib/mail/encodings.rb, line 53 def Encodings.transcode_charset(str, from_charset, to_charset = 'UTF-8') if from_charset Utilities.transcode_charset str, from_charset, to_charset else str end end
Takes an encoded string of the format =?<encoding>??<string>?=
# File lib/mail/encodings.rb, line 140 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 output.encode(to_encoding) rescue 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
Decodes a given string as Base64
or Quoted Printable, depending on what type it is.
String has to be of the format =?<encoding>??<string>?=
# File lib/mail/encodings.rb, line 122 def Encodings.value_decode(str) # Optimization: If there's no encoded-words in the string, just return it return str unless str =~ ENCODED_VALUE lines = collapse_adjacent_encodings(str) # Split on white-space boundaries with capture, so we capture the white-space as well lines.each do |line| line.gsub!(ENCODED_VALUE) do |string| case $2 when *B_VALUES then b_value_decode(string) when *Q_VALUES then q_value_decode(string) end end end.join("") end
Private Class Methods
Decodes a Base64
string from the “=?UTF-8?B?VGhpcyBpcyDjgYIgc3RyaW5n?=” format
Example:
Encodings.b_value_decode("=?UTF-8?B?VGhpcyBpcyDjgYIgc3RyaW5n?=") #=> 'This is あ string'
# File lib/mail/encodings.rb, line 234 def Encodings.b_value_decode(str) Utilities.b_value_decode(str) end
Split header line into proper encoded and unencoded parts.
String has to be of the format =?<encoding>??<string>?=
Omit unencoded space after an encoded-word.
# File lib/mail/encodings.rb, line 258 def Encodings.collapse_adjacent_encodings(str) results = [] last_encoded = nil # Track whether to preserve or drop whitespace lines = str.split(FULL_ENCODED_VALUE) lines.each_slice(2) do |unencoded, encoded| if last_encoded = encoded if !Utilities.blank?(unencoded) || (!last_encoded && unencoded != EMPTY) results << unencoded end results << encoded else results << unencoded end end results end
Partition the string into bounded-size chunks without splitting multibyte characters.
# File lib/mail/encodings.rb, line 280 def Encodings.each_base64_chunk_byterange(str, max_bytesize_per_base64_chunk, &block) raise "size per chunk must be multiple of 4" if (max_bytesize_per_base64_chunk % 4).nonzero? if block_given? max_bytesize = ((3 * max_bytesize_per_base64_chunk) / 4.0).floor each_chunk_byterange(str, max_bytesize, &block) else enum_for :each_base64_chunk_byterange, str, max_bytesize_per_base64_chunk end end
Partition the string into bounded-size chunks without splitting multibyte characters.
# File lib/mail/encodings.rb, line 293 def Encodings.each_chunk_byterange(str, max_bytesize_per_chunk) return enum_for(:each_chunk_byterange, str, max_bytesize_per_chunk) unless block_given? offset = 0 chunksize = 0 str.each_char do |chr| charsize = chr.bytesize if chunksize + charsize > max_bytesize_per_chunk yield Utilities.string_byteslice(str, offset, chunksize) offset += chunksize chunksize = charsize else chunksize += charsize end end yield Utilities.string_byteslice(str, offset, chunksize) end
Decodes a Quoted-Printable string from the “=?UTF-8?Q?This_is_=E3=81=82_string?=” format
Example:
Encodings.q_value_decode("=?UTF-8?Q?This_is_=E3=81=82_string?=") #=> 'This is あ string'
# File lib/mail/encodings.rb, line 244 def Encodings.q_value_decode(str) Utilities.q_value_decode(str) end
Gets the encoding type (Q or B) from the string.
# File lib/mail/encodings.rb, line 249 def Encodings.value_encoding_from_string(str) str[ENCODED_VALUE, 1] end