Signed-off-by: Adrian Hinz <ahinz@voicetelecom.pl>

Gemfile

@@ -35,7 +35,8 @@ gem 'jbuilder', '~> 2.5'
 
 # Use Capistrano for deployment
 # gem 'capistrano-rails', group: :development
-
+gem 'wicked_pdf'
+gem 'wkhtmltopdf-binary'
 group :development, :test do
   # Call 'byebug' anywhere in the code to stop execution and get a debugger console
   gem 'byebug', platform: :mri

app/controllers/invoices_controller.rb

@@ -5,6 +5,14 @@ class InvoicesController < ApplicationController
 
   def show
     @invoice = Invoice.find(params[:id])
+    respond_to do |format|
+      format.html
+      format.pdf do
+        render pdf: "Faktura_VAT_#{@invoice.id}",   # Excluding ".pdf" extension.
+        disposition: 'attachment',
+        exe_path: ''
+      end
+    end
   end
 
   def new

app/views/invoices/_show.html.erb

@@ -180,6 +180,30 @@
             </table>
           </div>
         </div>
+        <div class="row">
+          <div class="col-md-12"><h1>&nbsp;</h1></div>
+        </div>
+        <div class="row">
+          <div class="col-md-1"></div>
+          <div class="col-md-4">
+            <table width="100%" border="1" class="table">
+              <tr><td>Sprzedający:</td></tr>
+              <tr>
+                <td height="150" valign="bottom" class="text-center" style="vertical-align:bottom;">Osoba upowazniona do wystawienia faktury VAT</td>
+              </tr>
+            </table>
+          </div>
+          <div class="col-md-2"></div>
+          <div class="col-md-4">
+            <table width="100%" border="1" class="table">
+              <tr><td>Kupujący:</td></tr>
+              <tr>
+                <td height="150" class="text-center" style="vertical-align:bottom;">Osoba upowazniona do odbioru faktury VAT</td>
+              </tr>
+            </table>
+          </div>
+          <div class="col-md-1"></div>
+        </div>
 
 			</div>
 		</div>

app/views/invoices/show.html.erb

@@ -3,6 +3,7 @@
     <div class="panel-title">Faktura: <%= @invoice.number %></div>
     <div class="panel-options">
       <%= link_to raw("<i class=\"glyphicon glyphicon-arrow-left text-success\"></i> " + I18n.t('back')), invoices_path, title: I18n.t('back'), class: "text-primary" %>
+      <%= link_to 'PDF', invoice_path(@invoice, format: :pdf) %>
     </div>
   </div>
     <div class="content-box-large box-with-header" style="background:#dddddd">

app/views/invoices/show.pdf.erb

@@ -0,0 +1 @@
+<%= render file: '/invoices/_show.html.erb' %>

config/initializers/mime_types.rb

@@ -2,3 +2,4 @@
 
 # Add new mime types for use in respond_to blocks:
 # Mime::Type.register "text/richtext", :rtf
+Mime::Type.register "application/pdf", :pdf

config/initializers/wicked_pdf.rb

@@ -0,0 +1,21 @@
+# WickedPDF Global Configuration
+#
+# Use this to set up shared configuration options for your entire application.
+# Any of the configuration options shown here can also be applied to single
+# models by passing arguments to the `render :pdf` call.
+#
+# To learn more, check out the README:
+#
+# https://github.com/mileszs/wicked_pdf/blob/master/README.md
+
+WickedPdf.config = {
+  # Path to the wkhtmltopdf executable: This usually isn't needed if using
+  # one of the wkhtmltopdf-binary family of gems.
+  # exe_path: 'c:/Program Files/wkhtmltopdf/bin/wkhtmltopdf',
+  #   or
+   exe_path: Gem.bin_path('wkhtmltopdf-binary', 'wkhtmltopdf')
+
+  # Layout file to be used for all PDFs
+  # (but can be overridden in `render :pdf` calls)
+  # layout: 'pdf.html',
+}