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_LOOKUP
- KNOWN_FIELDS
- STRUCTURED_FIELDS
Attributes
Public Class Methods
Source
# File lib/mail/field.rb, line 166 def initialize(name, value = nil, charset = 'utf-8') case when name.index(Constants::COLON) raise ArgumentError, 'Passing an unparsed header field to Mail::Field.new is not supported in Mail 2.8.0+. Use Mail::Field.parse instead.' when Utilities.blank?(value) @name = name @unparsed_value = nil @charset = charset else @name = name @unparsed_value = value @charset = charset end @name = FIELD_NAME_MAP[@name.to_s.downcase] || @name end
Create a field by name and optional value:
Mail::Field.new("field-name", "value") # => #<Mail::Field …>
Values that aren’t strings or arrays are coerced to Strings with ‘#to_s`.
Mail::Field.new("field-name", 1234) # => #<Mail::Field …> Mail::Field.new('content-type', ['text', 'plain', {:charset => 'UTF-8'}]) # => #<Mail::Field …>
Source
# File lib/mail/field.rb, line 122 def parse(field, charset = 'utf-8') name, value = split(field) if name && value new name, value, charset end end
Parse a field from a raw header line:
Mail::Field.parse("field-name: field data") # => #<Mail::Field …>
Public Instance Methods
Source
# File lib/mail/field.rb, line 224 def <=>(other) field_order_id <=> other.field_order_id end
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# File lib/mail/field.rb, line 216 def ==(other) same(other) && Utilities.match_to_s(other.value, value) end
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# File lib/mail/field.rb, line 186 def field @field ||= create_field(@name, @unparsed_value, @charset) end
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# File lib/mail/field.rb, line 228 def field_order_id @field_order_id ||= FIELD_ORDER_LOOKUP.fetch(self.name.to_s.downcase, 100) end
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# File lib/mail/field.rb, line 206 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
Source
# File lib/mail/field.rb, line 232 def method_missing(name, *args, &block) field.send(name, *args, &block) end
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# File lib/mail/field.rb, line 236 def respond_to_missing?(method_name, include_private) field.respond_to?(method_name, include_private) || super end
Calls superclass method
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# File lib/mail/field.rb, line 220 def responsible_for?(field_name) name.to_s.casecmp(field_name.to_s) == 0 end
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# File lib/mail/field.rb, line 212 def same(other) other.kind_of?(self.class) && Utilities.match_to_s(other.name, name) end
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# File lib/mail/field.rb, line 198 def value=(val) @field = create_field(name, val, @charset) end
Private Instance Methods
Source
# File lib/mail/field.rb, line 253 def create_field(name, value, charset) parse_field(name, value, charset) rescue Mail::Field::ParseError => e field = Mail::UnstructuredField.new(name, value) field.errors << [name, value, e] field end
Source
# File lib/mail/field.rb, line 261 def parse_field(name, value, charset) value = unfold(value) if value.is_a?(String) if klass = self.class.field_class_for(name) klass.parse(value, charset) else OptionalField.parse(name, value, charset) end end
Source
# File lib/mail/field.rb, line 279 def unfold(string) string.gsub(Constants::UNFOLD_WS, '\1') end
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.