summaryrefslogtreecommitdiff
path: root/lib/rss/converter.rb
blob: b92e35a051d172779d20e7937b009e0e8ec99a27 (plain)
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
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
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
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
# frozen_string_literal: false
require "rss/utils"

module RSS

  class Converter

    include Utils

    def initialize(to_enc, from_enc=nil)
      if "".respond_to?(:encode)
        @to_encoding = to_enc
        return
      end
      normalized_to_enc = to_enc.downcase.gsub(/-/, '_')
      from_enc ||= 'utf-8'
      normalized_from_enc = from_enc.downcase.gsub(/-/, '_')
      if normalized_to_enc == normalized_from_enc
        def_same_enc()
      else
        def_diff_enc = "def_to_#{normalized_to_enc}_from_#{normalized_from_enc}"
        if respond_to?(def_diff_enc)
          __send__(def_diff_enc)
        else
          def_else_enc(to_enc, from_enc)
        end
      end
    end

    def convert(value)
      if value.is_a?(String) and value.respond_to?(:encode)
        value.encode(@to_encoding)
      else
        value
      end
    end

    def def_convert(depth=0)
      instance_eval(<<-EOC, *get_file_and_line_from_caller(depth))
      def convert(value)
        if value.kind_of?(String)
          #{yield('value')}
        else
          value
        end
      end
      EOC
    end

    def def_iconv_convert(to_enc, from_enc, depth=0)
      begin
        require "iconv"
        @iconv = Iconv.new(to_enc, from_enc)
        def_convert(depth+1) do |value|
          <<-EOC
          begin
            @iconv.iconv(#{value})
          rescue Iconv::Failure
            raise ConversionError.new(#{value}, "#{to_enc}", "#{from_enc}")
          end
          EOC
        end
      rescue LoadError, ArgumentError, SystemCallError
        raise UnknownConversionMethodError.new(to_enc, from_enc)
      end
    end

    def def_else_enc(to_enc, from_enc)
      def_iconv_convert(to_enc, from_enc, 0)
    end

    def def_same_enc()
      def_convert do |value|
        value
      end
    end

    def def_uconv_convert_if_can(meth, to_enc, from_enc, nkf_arg)
      begin
        require "uconv"
        def_convert(1) do |value|
          <<-EOC
          begin
            Uconv.#{meth}(#{value})
          rescue Uconv::Error
            raise ConversionError.new(#{value}, "#{to_enc}", "#{from_enc}")
          end
          EOC
        end
      rescue LoadError
        require 'nkf'
        if NKF.const_defined?(:UTF8)
          def_convert(1) do |value|
            "NKF.nkf(#{nkf_arg.dump}, #{value})"
          end
        else
          def_iconv_convert(to_enc, from_enc, 1)
        end
      end
    end

    def def_to_euc_jp_from_utf_8
      def_uconv_convert_if_can('u8toeuc', 'EUC-JP', 'UTF-8', '-We')
    end

    def def_to_utf_8_from_euc_jp
      def_uconv_convert_if_can('euctou8', 'UTF-8', 'EUC-JP', '-Ew')
    end

    def def_to_shift_jis_from_utf_8
      def_uconv_convert_if_can('u8tosjis', 'Shift_JIS', 'UTF-8', '-Ws')
    end

    def def_to_utf_8_from_shift_jis
      def_uconv_convert_if_can('sjistou8', 'UTF-8', 'Shift_JIS', '-Sw')
    end

    def def_to_euc_jp_from_shift_jis
      require "nkf"
      def_convert do |value|
        "NKF.nkf('-Se', #{value})"
      end
    end

    def def_to_shift_jis_from_euc_jp
      require "nkf"
      def_convert do |value|
        "NKF.nkf('-Es', #{value})"
      end
    end

    def def_to_euc_jp_from_iso_2022_jp
      require "nkf"
      def_convert do |value|
        "NKF.nkf('-Je', #{value})"
      end
    end

    def def_to_iso_2022_jp_from_euc_jp
      require "nkf"
      def_convert do |value|
        "NKF.nkf('-Ej', #{value})"
      end
    end

    def def_to_utf_8_from_iso_8859_1
      def_convert do |value|
        "#{value}.unpack('C*').pack('U*')"
      end
    end

    def def_to_iso_8859_1_from_utf_8
      def_convert do |value|
        <<-EOC
        array_utf8 = #{value}.unpack('U*')
        array_enc = []
        array_utf8.each do |num|
          if num <= 0xFF
            array_enc << num
          else
            array_enc.concat "&\#\#{num};".unpack('C*')
          end
        end
        array_enc.pack('C*')
        EOC
      end
    end

  end

end