embedding barcode generated with barby gem into the prawn document

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?

Ergot

The Barby github page is: github.com/toretore/barby – Talishatalisman

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

Carrell

I've updated my post to make it more clear. If you see, I'm creating new pdf file within from controller by invoking InvoicePdf class. Your hints still don't give me a clue how to change the barcode method. The 1st method you wrote didn't embed a barcode. – Ergot

I've updated my answer. The XXXX needs to be a Prawn::Document, which is here the InvoicePdf instance (self). – Carrell

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

Slugabed