generating barcode for Barby gem under EAN-13

Question

While attempting to render in HTML a collection of article barcodes and proceeding incrementally to view the data (relative to other objects on tha page), the controller

require 'barby/outputter/html_outputter'
require 'barby/barcode/ean_13'

and the view invokes

<%= this_barcode = article.barcodes.first.barcode %>
<%= this_barcode.class %>
<%# barcode = Barby::EAN13.new(this_barcode) %>
<%# outputter = Barby::HtmlOutputter.new(barcode) %>
<%# barcode.to_html.html_safe %>
     [returns as expected]
8001300303466 String

however, when wanting to get the barcode and uncommenting that element it fails to process because data not valid for the line barcode = Barby::EAN13.new(this_barcode) (also occurs with barcode = Barby::EAN13.new(this_barcode.to_i))

note possibly on garden path here, as there is confusion with what the wiki suggests with
barcode = Barby::DataMatrix.new(number) as that would generate the error
uninitialized constant Barby::DataMatrix

How does one ensure the data is correct for proper rendering?

Answer 1

Here's the issue: 8001300303466 has 13 characters. It is the correct barcode.

I was assuming one could submit a correct barcode. However line 54 of the gem's ean_13.rb file allows a 12 character data element FORMAT = /^\d{12}$/ and proceeds to calculate the check digit.

Thus,

<%= barcode = Barby::EAN13.new(this_barcode[0...-1]) %>

will end up processing the data correctly.