embedding barcode generated with barby gem into the prawn document - ruby

Question

From my controller I create pdf:
def show
#order = Order.find(params[:id])
respond_to do |format|
format.html # show.html.erb
format.json { render json: #order }
format.pdf do
pdf = InvoicePdf.new(#order, view_context)
send_data pdf.render, filename: "invoice_#{#order.order_number}.pdf",
type: "application/pdf",
disposition: "inline",
size: 10
end
end
end
invoice_pdf.rb:
require 'barby'
require 'barby/barcode/code_39'
require 'barby/outputter/prawn_outputter'
class InvoicePdf < Prawn::Document
def initialize(order, view)
super({
:top_margin => 70,
:page_size => 'A4',
:font_size => 10,
:text => 8
})
#order = order
#view = view
order_number
barcode
end
def order_number
text "Order #{#order.order_number}"
end
def barcode
barcode = Barby::Code39.new #order.order_number
barcode.annotate_pdf(XXXX)
end
end
How should I modify my barcode method or the options marked as XXXX to embed barcode into PDF document?

Answer 1

EDIT
In your InvoicePdf class, change the barcode method to:
def barcode
barcode = Barby::Code39.new #order.order_number
barcode.annotate_pdf(self)
end
The annotate_pdf method takes a Prawn::Document as its argument, which is self here.
Original Answer
If you want to create a new pdf with your barcode, you can just do:
def barcode
_barcode = Barby::Code39.new(#order.order_number)
outputter = Barby::PrawnOutputter.new(_barcode)
outputter.to_pdf
end
Note that you can specify pdf options (including height, margins, page size, etc.) on the new PrawnOutputter or on the to_pdf call. See the documentation for more details: https://github.com/toretore/barby/wiki/Outputters and http://rdoc.info/github/toretore/barby/Barby/PrawnOutputter.
And if you want to write it to a file do:
File.open("my_file.pdf","w") { |f| f.print barcode }
Note that you can also just call _barcode.to_pdf, which seems to have the same effect as creating a new PrawnOutputter, but this functionality is not described in the Barby documentation.
If you have an existing pdf document (as a Prawn::Document) that you want to write a barcode to, note that you could do:
def barcode(p_pdf)
_barcode = Barby::Code39.new(#order.order_number)
_barcode.annotate_pdf(p_pdf)
end

Answer 2

In my case, barcode.annotate_pdf(self) was throwing some errors because it wasn't recognizing attributes like fill_color, so I ended up creating the Barby barcode as a PNG image and then inserting it in the PDF. Something like this:
require 'barby'
require 'barby/barcode/code_128'
require 'barby/outputter/png_outputter'
...
pdf = Prawn::Document.new(page_size: 'A4', margin: 20)
# Print data as text
order = "Order ##{#data.order_number} "
pdf.text_box order, size: 12, at: [0, pdf.cursor], width: 550
# Print data as image
barcode = Barby::Code128.new #data.order_number
barcode_blob = Barby::PngOutputter.new(barcode).to_png
# barcode.png is stored in tmp directory
File.open("tmp/barcode.png", 'wb'){|f| f.write barcode.to_png }
pdf.image "#{Rails.root.to_s}/tmp/barcode.png", image_width: 50, image_height: 50, position: :center
...
pdf.render
Option #2: Using StringIO instead of tmp File
# Print data as image
barcode = Barby::Code128.new #data.order_number
barcode_blob = Barby::PngOutputter.new(barcode).to_png
barcode_io = StringIO.new(barcode_blob)
barcode_io.rewind
pdf.image(barcode_io, image_width: 50, image_height: 50, position: :center)
...
pdf.render