Fix ordering worksheet API for date objects

tailbone/api/batch/ordering.py

@@ -29,6 +29,8 @@ API.
 
 from __future__ import unicode_literals, absolute_import
 
+import datetime
+
 import six
 
 from rattail.db import model
@@ -94,6 +96,8 @@ class OrderingBatchViews(APIBatchView):
         if batch.executed:
             raise self.forbidden()
 
+        app = self.get_rattail_app()
+
         # TODO: much of the logic below was copied from the traditional master
         # view for ordering batches.  should maybe let them share it somehow?
 
@@ -179,6 +183,16 @@ class OrderingBatchViews(APIBatchView):
         for i in range(6 - len(history)):
             history.append(None)
         history = list(reversed(history))
+        # must convert some date objects to string, for JSON sake
+        for h in history:
+            purchase = h.get('purchase')
+            if purchase:
+                dt = purchase.get('date_ordered')
+                if dt and isinstance(dt, datetime.date):
+                    purchase['date_ordered'] = app.render_date(dt)
+                dt = purchase.get('date_received')
+                if dt and isinstance(dt, datetime.date):
+                    purchase['date_received'] = app.render_date(dt)
 
         return {
             'batch': self.normalize(batch),