Fixed #1. A function is now available to convert a summary into a jso…

…n encoded string. This was preferred over a method to keep things nicely separated and to avoid name clashes.

rollyourown/commerce/__init__.py

@@ -7,6 +7,7 @@
 
 """
 __authors__ = ["Will Hardy <rollyourown@willhardy.com.au>"]
-__all__ = ( 'Summary', 'Extra', 'Items', 'Total',)
+__all__ = ( 'Summary', 'Extra', 'Items', 'Total', 'json_summary')
 
 from summary import Summary, Extra, Items, Total
+from utils import json_summary

rollyourown/commerce/utils/__init__.py

@@ -1,4 +1,24 @@
 from rollyourown.commerce.utils.friendly_id import FriendlyID
 from rollyourown.commerce.utils.formatting import FormattedDecimal
 
-__all__ = ('FriendlyID', 'FormattedDecimal')
+__all__ = ('FriendlyID', 'FormattedDecimal', 'json_summary')
+
+from django.utils import simplejson
+from django.core.serializers.json import DjangoJSONEncoder
+
+def json_summary(summary, fields=None):
+    """ serialize the given summary to JSON. """
+
+    data = {}
+    for items in summary._meta.items.keys():
+        if fields and items in fields:
+            data[items] = dict((i.pk, getattr(i, summary._meta.items[items].cache_amount_as)) for i in getattr(summary, items))
+    for extra in summary._meta.extras:
+        if fields and extra in fields:
+            data[extra] = getattr(summary, extra).amount
+    for total in summary._meta.totals:
+        if fields and total in fields:
+            data[total] = getattr(summary, total)
+
+    return simplejson.dumps(data, cls=DjangoJSONEncoder)
+