some exploration about creating PDFs from a resque background job with PDFKit

pdf_document.rb

class PDFDocument
  include ActionDispatch::Integration::Runner  # lets you grab assets. See #session
  include Rails.application.routes.url_helpers

  # quote or invoice or receipt
  def initialize(document)
    @document = document
  end

  def pdf
    PDFKit.new(translate_paths(fetch_html))
  end

  def fetch_html
    status_code = session.get invoice_order_path(@document)
    if status_code == 200
      doc = Nokogiri::HTML.parse(session.body)

      # inject stylesheets inline, do something similar for images
      stylesheets = doc.css('head link').map {|element|
        href = element.attr('href')
        if session.get(href) == 200
          element.remove
          element.after(session.body)  # pseudo code, append the actual styles inline
        end
      }

      doc.to_html
    else
      "TODO: non 200 status code"
    end
  end

  # Internal
  def app
    @app ||= Rails.application
  end

  def session
    @session ||= open_session
  end
end

File.open("bar.pdf", "wb") {|f|
  f.puts PDFDocument.new(Order.last).pdf.to_pdf
}