1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
|
# frozen_string_literal: true
# Released under the MIT License.
# Copyright, 2016, by Matthew Kerwin.
# Copyright, 2017-2024, by Samuel Williams.
require 'strscan'
require_relative 'parse_error'
require_relative 'quoted_string'
require_relative 'sort'
module HTTP
module Accept
module Charsets
# https://tools.ietf.org/html/rfc7231#section-5.3.1
QVALUE = /0(\.[0-9]{0,3})?|1(\.[0]{0,3})?/
# https://tools.ietf.org/html/rfc7231#section-5.3.3
CHARSETS = /(?<charset>#{TOKEN})(;q=(?<q>#{QVALUE}))?/
Charset = Struct.new(:charset, :q) do
def quality_factor
(q || 1.0).to_f
end
def self.parse(scanner)
return to_enum(:parse, scanner) unless block_given?
while scanner.scan(CHARSETS)
yield self.new(scanner[:charset], scanner[:q])
# Are there more?
break unless scanner.scan(/\s*,\s*/)
end
raise ParseError.new('Could not parse entire string!') unless scanner.eos?
end
end
def self.parse(text)
scanner = StringScanner.new(text)
charsets = Charset.parse(scanner)
return Sort.by_quality_factor(charsets)
end
HTTP_ACCEPT_CHARSET = 'HTTP_ACCEPT_CHARSET'.freeze
WILDCARD_CHARSET = Charset.new('*', nil).freeze
# Parse the list of browser preferred charsets and return ordered by priority.
def self.browser_preferred_charsets(env)
if accept_charsets = env[HTTP_ACCEPT_CHARSET]&.strip
if accept_charsets.empty?
# https://tools.ietf.org/html/rfc7231#section-5.3.3 :
#
# Accept-Charset = 1#( ( charset / "*" ) [ weight ] )
#
# Because of the `1#` rule, an empty header value is not considered valid.
raise ParseError.new('Could not parse entire string!')
else
return HTTP::Accept::Charsets.parse(accept_charsets)
end
end
# "A request without any Accept-Charset header field implies that the
# user agent will accept any charset in response."
return [WILDCARD_CHARSET]
end
end
end
end
|
