Add ability to download receipts in PDF form

util/invoice.py

@@ -1,5 +1,7 @@
 from datetime import datetime
 from jinja2 import Environment, FileSystemLoader
+from xhtml2pdf import pisa
+import StringIO
 
 jinja_options = {
   "loader": FileSystemLoader('util'),
@@ -7,6 +9,20 @@ jinja_options = {
 
 env = Environment(**jinja_options)
 
+
+def renderInvoiceToPdf(invoice, user):
+  """ Renders a nice PDF display for the given invoice. """
+  sourceHtml = renderInvoiceToHtml(invoice, user)
+  output = StringIO.StringIO()
+  pisaStatus = pisa.CreatePDF(sourceHtml, dest=output)
+  if pisaStatus.err:
+    return None
+  
+  value = output.getvalue()
+  output.close()
+  return value
+
+
 def renderInvoiceToHtml(invoice, user):
   """ Renders a nice HTML display for the given invoice. """
   def get_price(price):