class Mail::Field

Provides a single class to call to create a new structured or unstructured field. Works out per RFC what field of field it is being given and returns the correct field of class back on new.

Per RFC 2822

2.2. Header Fields

   Header fields are lines composed of a field name, followed by a colon
   (":"), followed by a field body, and terminated by CRLF.  A field
   name MUST be composed of printable US-ASCII characters (i.e.,
   characters that have values between 33 and 126, inclusive), except
   colon.  A field body may be composed of any US-ASCII characters,
   except for CR and LF.  However, a field body may contain CRLF when
   used in header "folding" and  "unfolding" as described in section
   2.2.3.  All field bodies MUST conform to the syntax described in
   sections 3 and 4 of this standard.

Constants

FIELDS_MAP
FIELD_NAME_MAP
FIELD_ORDER
FIELD_ORDER_LOOKUP
KNOWN_FIELDS
STRUCTURED_FIELDS

Public Class Methods

new(name, value = nil, charset = 'utf-8') click to toggle source

Accepts a string:

Field.new("field-name: field data")

Or name, value pair:

Field.new("field-name", "value")

Or a name by itself:

Field.new("field-name")

Note, does not want a terminating carriage return. Returns self appropriately parsed. If value is not a string, then it will be passed through as is, for example, content-type field can accept an array with the type and a hash of parameters:

Field.new('content-type', ['text', 'plain', {:charset => 'UTF-8'}])
# File lib/mail/field.rb, line 114
def initialize(name, value = nil, charset = 'utf-8')
  case
  when name.index(COLON)            # Field.new("field-name: field data")
    @charset = value.blank? ? charset : value
    @name = name[FIELD_PREFIX]
    @raw_value = name
    @value = nil
  when value.blank?                 # Field.new("field-name")
    @name = name
    @value = nil
    @raw_value = nil
    @charset = charset
  else                              # Field.new("field-name", "value")
    @name = name
    @value = value
    @raw_value = nil
    @charset = charset
  end
  @name = FIELD_NAME_MAP[@name.to_s.downcase] || @name
end

Public Instance Methods

<=>( other ) click to toggle source
# File lib/mail/field.rb, line 180
def <=>( other )
  self.field_order_id <=> other.field_order_id
end
==( other )
Alias for: same
field() click to toggle source
# File lib/mail/field.rb, line 139
def field
  _, @value = split(@raw_value) if @raw_value && !@value
  @field ||= create_field(@name, @value, @charset)
end
field=(value) click to toggle source
# File lib/mail/field.rb, line 135
def field=(value)
  @field = value
end
field_order_id() click to toggle source
# File lib/mail/field.rb, line 184
def field_order_id
  @field_order_id ||= (FIELD_ORDER_LOOKUP[self.name.to_s.downcase] || 100)
end
inspect() click to toggle source
# File lib/mail/field.rb, line 160
def inspect
  "#<#{self.class.name} 0x#{(object_id * 2).to_s(16)} #{instance_variables.map do |ivar|
    "#{ivar}=#{instance_variable_get(ivar).inspect}"
  end.join(" ")}>"
end
method_missing(name, *args, &block) click to toggle source
# File lib/mail/field.rb, line 188
def method_missing(name, *args, &block)
  field.send(name, *args, &block)
end
name() click to toggle source
# File lib/mail/field.rb, line 144
def name
  @name
end
responsible_for?( val ) click to toggle source
# File lib/mail/field.rb, line 174
def responsible_for?( val )
  name.to_s.casecmp(val.to_s) == 0
end
same( other ) click to toggle source
# File lib/mail/field.rb, line 170
def same( other )
  match_to_s(other.name, self.name)
end
Also aliased as: ==
to_s() click to toggle source
# File lib/mail/field.rb, line 156
def to_s
  field.to_s
end
update(name, value) click to toggle source
# File lib/mail/field.rb, line 166
def update(name, value)
  @field = create_field(name, value, @charset)
end
value() click to toggle source
# File lib/mail/field.rb, line 148
def value
  field.value
end
value=(val) click to toggle source
# File lib/mail/field.rb, line 152
def value=(val)
  @field = create_field(name, val, @charset)
end

Private Instance Methods

create_field(name, value, charset) click to toggle source
# File lib/mail/field.rb, line 224
def create_field(name, value, charset)
  value = unfold(value) if value.is_a?(String)

  begin
    new_field(name, value, charset)
  rescue Mail::Field::ParseError => e
    field = Mail::UnstructuredField.new(name, value)
    field.errors << [name, value, e]
    field
  end
end
new_field(name, value, charset) click to toggle source
# File lib/mail/field.rb, line 236
def new_field(name, value, charset)
  lower_case_name = name.to_s.downcase
  if field_klass = FIELDS_MAP[lower_case_name]
    field_klass.new(value, charset)
  else
    OptionalField.new(name, value, charset)
  end
end
split(raw_field) click to toggle source
# File lib/mail/field.rb, line 205
def split(raw_field)
  match_data = raw_field.mb_chars.match(FIELD_SPLIT)
  [match_data[1].to_s.mb_chars.strip, match_data[2].to_s.mb_chars.strip.to_s]
rescue
  STDERR.puts "WARNING: Could not parse (and so ignoring) '#{raw_field}'"
end
unfold(string) click to toggle source

2.2.3. Long Header Fields

The process of moving from this folded multiple-line representation
of a header field to its single line representation is called
"unfolding". Unfolding is accomplished by simply removing any CRLF
that is immediately followed by WSP.  Each header field should be
treated in its unfolded form for further syntactic and semantic
evaluation.
# File lib/mail/field.rb, line 220
def unfold(string)
  string.gsub(/[\r\n \t]+/m, ' ')
end