gistfile1.rb

# model invoice

  def store_pdf
    # this should be constant
    temp_invoice_file_path = Rails.root.join("html2pdf/invoice.html")
    File.open(temp_invoice_file_path, 'w') {|f| f.write(markup) }
    if ENV['OS'] and ENV['OS'].include?("Windows")
      `xhtml2pdf html2pdf/invoice.html #{filepath}`
    else
      `python pisa.py #{temp_invoice_file_path} #{filepath}`
    end
    # File.delete(temp_invoice_file_path)
    filepath
  end

  def filepath(extension='pdf')
    Rails.root.join "html2pdf/invoice_cache/#{filename}.#{extension}"
  end


# controller mail

 def create
    params[:mailing][:filepaths] = [[ @invoice.store_pdf, @invoice.filename+".pdf"]]
    if Mailing.create(params[:mailing])
      @invoice.update_attribute(:emailed_at, Time.now)
    end

    respond_to do |format|
      format.html {redirect_to invoicing_invoice_path(@invoice)}
    end
  end