Class: Barcode1DTools::Matrix2of5
- Defined in:
- lib/barcode1dtools/matrix2of5.rb
Overview
Barcode1DTools::Matrix2of5 - Create and decode bar patterns for Matrix 2 of 5. The value encoded is a number with digits 0-9. Internally, the value is treated as a string to preserve leading zeroes.
Use :checksum_included => true if you have already added a checksum and wish to have it validated, or :skip_checksum => true if you don’t wish to add one or have it validated.
Matrix 2 of 5 is low-density and limited. It should not be used in any new applications.
val = “3423” bc = Barcode1DTools::Matrix2of5.new(val) pattern = bc.bars rle_pattern = bc.rle width = bc.width
The object created is immutable.
Barcode1DTools::Matrix2of5 creates the patterns that you need to display Matrix 2 of 5 barcodes. It can also decode a simple w/n string.
Matrix2of5 characters consist of 3 bars and 2 spaces, with a narrow space between them. 2 of the bars/spaces in each symbol are wide.
There are three formats for the returned pattern:
bars - 1s and 0s specifying black lines and white spaces. Actual
characters can be changed from "1" and 0" with options
:line_character and :space_character.
rle - Run-length-encoded version of the pattern. The first
number is always a black line, with subsequent digits
alternating between spaces and lines. The digits specify
the width of each line or space.
wn - The native format for this barcode type. The string
consists of a series of "w" and "n" characters. The first
item is always a black line, with subsequent characters
alternating between spaces and lines. A "wide" item
is twice the width of a "narrow" item.
The “width” method will tell you the total end-to-end width, in units, of the entire barcode.
Rendering
The standard w/n ratio seems to be 2:1. There seem to be no real standards for display.
Constant Summary collapse
- CHAR_SEQUENCE =
Character sequence - 0-based offset in this string is character number
"0123456789"
- PATTERNS =
Patterns for making bar codes. Note that the position weights are 1, 2, 4, and 7, and the last bit is parity. Each letter is an alternating bar then space, and there is a narrow space between each character.
{ '0'=> {'val'=>0 ,'wn'=>'nnwwn'}, '1'=> {'val'=>1 ,'wn'=>'wnnnw'}, '2'=> {'val'=>2 ,'wn'=>'nwnnw'}, '3'=> {'val'=>3 ,'wn'=>'wwnnn'}, '4'=> {'val'=>4 ,'wn'=>'nnwnw'}, '5'=> {'val'=>5 ,'wn'=>'wnwnn'}, '6'=> {'val'=>6 ,'wn'=>'nwwnn'}, '7'=> {'val'=>7 ,'wn'=>'nnnww'}, '8'=> {'val'=>8 ,'wn'=>'wnnwn'}, '9'=> {'val'=>9 ,'wn'=>'nwnwn'} }
- GUARD_PATTERN_LEFT_WN =
'wnnnn'
- GUARD_PATTERN_RIGHT_WN =
'wnnnn'
- DEFAULT_OPTIONS =
{ :line_character => '1', :space_character => '0', :w_character => 'w', :n_character => 'n', :wn_ratio => '2' }
Instance Attribute Summary
Attributes inherited from Barcode1D
#check_digit, #encoded_string, #options, #value
Class Method Summary collapse
-
.can_encode?(value) ⇒ Boolean
Matrix2of5 can encode digits.
-
.decode(str, options = {}) ⇒ Object
Decode a string in rle format.
- .generate_check_digit_for(value) ⇒ Object
- .validate_check_digit_for(value) ⇒ Object
Instance Method Summary collapse
-
#bars ⇒ Object
returns 1s and 0s (for “black” and “white”).
-
#initialize(value, options = {}) ⇒ Matrix2of5
constructor
Options are :line_character, :space_character, :w_character, :n_character, :checksum_included, and :skip_checksum.
-
#rle ⇒ Object
returns a run-length-encoded string representation.
-
#width ⇒ Object
returns the total unit width of the bar code.
-
#wn ⇒ Object
Returns a string of “w” or “n” (“wide” and “narrow”).
Methods inherited from Barcode1D
bar_pair, bars_to_rle, rle_to_bars, rle_to_wn, wn_pair, wn_to_rle
Constructor Details
#initialize(value, options = {}) ⇒ Matrix2of5
Options are :line_character, :space_character, :w_character, :n_character, :checksum_included, and :skip_checksum.
168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 |
# File 'lib/barcode1dtools/matrix2of5.rb', line 168 def initialize(value, = {}) @options = DEFAULT_OPTIONS.merge() # Can we encode this value? raise UnencodableCharactersError unless self.class.can_encode?(value) @value = value.to_s if @options[:skip_checksum] @encoded_string = value.to_s @value = value.to_s @check_digit = nil elsif @options[:checksum_included] @encoded_string = value.to_s raise ChecksumError unless self.class.validate_check_digit_for(@encoded_string) md = @encoded_string.match(/^(\d+?)(\d)$/) @value, @check_digit = md[1], md[2].to_i else @value = value.to_s @check_digit = self.class.generate_check_digit_for(@value) @encoded_string = "#{@value}#{@check_digit}" end end |
Class Method Details
.can_encode?(value) ⇒ Boolean
Matrix2of5 can encode digits
98 99 100 |
# File 'lib/barcode1dtools/matrix2of5.rb', line 98 def can_encode?(value) value.to_s =~ /\A[0-9]+\z/ end |
.decode(str, options = {}) ⇒ Object
Decode a string in rle format. This will return a Matrix2of5 object.
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 |
# File 'lib/barcode1dtools/matrix2of5.rb', line 117 def decode(str, = {}) if str =~ /[^1-3]/ && str =~ /[^wn]/ raise UnencodableCharactersError, "Pattern must be rle or wn" end # ensure a wn string if str =~ /[1-3]/ str = str.tr('123','nww') end if str.reverse =~ /\A#{GUARD_PATTERN_LEFT_WN}n.*?#{GUARD_PATTERN_RIGHT_WN}\z/ str.reverse! end unless str =~ /\A#{GUARD_PATTERN_LEFT_WN}n(.*?)#{GUARD_PATTERN_RIGHT_WN}\z/ raise UnencodableCharactersError, "Start/stop pattern is not detected." end wn_pattern = $1 # Each pattern is 3 bars and 2 spaces, with a space between. unless wn_pattern.size % 6 == 0 raise UnencodableCharactersError, "Wrong number of bars." end decoded_string = '' wn_pattern.scan(/(.{5})n/).each do |chunk| chunk = chunk.first found = false PATTERNS.each do |char,hsh| if chunk == hsh['wn'] decoded_string += char found = true break; end end raise UndecodableCharactersError, "Invalid sequence: #{chunk}" unless found end Matrix2of5.new(decoded_string, ) end |
.generate_check_digit_for(value) ⇒ Object
102 103 104 105 106 107 |
# File 'lib/barcode1dtools/matrix2of5.rb', line 102 def generate_check_digit_for(value) raise UnencodableCharactersError unless self.can_encode?(value) mult = 3 value = value.reverse.split('').inject(0) { |a,c| mult = 4 - mult ; a + c.to_i * mult } (10 - (value % 10)) % 10 end |
.validate_check_digit_for(value) ⇒ Object
109 110 111 112 113 |
# File 'lib/barcode1dtools/matrix2of5.rb', line 109 def validate_check_digit_for(value) raise UnencodableCharactersError unless self.can_encode?(value) md = value.match(/^(\d+?)(\d)$/) self.generate_check_digit_for(md[1]) == md[2].to_i end |
Instance Method Details
#bars ⇒ Object
returns 1s and 0s (for “black” and “white”)
204 205 206 |
# File 'lib/barcode1dtools/matrix2of5.rb', line 204 def @bars ||= self.class.(self.rle, @options) end |
#rle ⇒ Object
returns a run-length-encoded string representation
199 200 201 |
# File 'lib/barcode1dtools/matrix2of5.rb', line 199 def rle @rle ||= self.class.wn_to_rle(self.wn, @options) end |
#width ⇒ Object
returns the total unit width of the bar code
209 210 211 |
# File 'lib/barcode1dtools/matrix2of5.rb', line 209 def width @width ||= rle.split('').inject(0) { |a,c| a + c.to_i } end |
#wn ⇒ Object
Returns a string of “w” or “n” (“wide” and “narrow”)
194 195 196 |
# File 'lib/barcode1dtools/matrix2of5.rb', line 194 def wn @wn ||= wn_str.tr('wn', @options[:w_character].to_s + @options[:n_character].to_s) end |