add south introspection, add json helper to load/dump time_struct

oxdjango/fields.py

@@ -1,7 +1,26 @@
+import time
+
 from django.db import models
 from django.utils import simplejson as json
 
 
+def to_json(python_object):
+    if isinstance(python_object, time.struct_time):          
+        return {'__class__': 'time.asctime',
+                '__value__': time.asctime(python_object)}    
+    if isinstance(python_object, bytes):
+        return {'__class__': 'bytes',
+                '__value__': list(python_object)}
+    raise TypeError(repr(python_object) + ' is not JSON serializable')
+
+def from_json(json_object):                                  
+    if '__class__' in json_object:                            
+        if json_object['__class__'] == 'time.asctime':
+            return time.strptime(json_object['__value__'])    
+        if json_object['__class__'] == 'bytes':
+            return bytes(json_object['__value__'])            
+    return json_object
+    
 class DictField(models.TextField):
     """DictField is a textfield that contains JSON-serialized dictionaries."""
 
@@ -13,7 +32,7 @@ class DictField(models.TextField):
         if isinstance(value, dict):
             return value
         try:
-            value = json.loads(value)
+            value = json.loads(value, object_hook=from_json)
         except: #this is required to load fixtures
             value = eval(value)
         assert isinstance(value, dict)
@@ -22,7 +41,7 @@ class DictField(models.TextField):
     def get_db_prep_save(self, value):
         """Convert our JSON object to a string before we save"""
         assert isinstance(value, dict)
-        value = json.dumps(value)
+        value = json.dumps(value, default=to_json)
         return super(DictField, self).get_db_prep_save(value)
 
 class TupleField(models.TextField):
@@ -37,7 +56,7 @@ class TupleField(models.TextField):
             return value
 
         try:
-            value = json.loads(value)
+            value = json.loads(value, object_hook=from_json)
         except: #this is required to load fixtures
             value = eval(value)
         assert isinstance(value, list)
@@ -46,6 +65,12 @@ class TupleField(models.TextField):
     def get_db_prep_save(self, value):
         """Convert our JSON object to a string before we save"""
         assert isinstance(value, tuple)
-        value = json.dumps(value)
+        value = json.dumps(value, default=to_json)
         return super(TupleField, self).get_db_prep_save(value)
 
+try:
+    from south.modelsinspector import add_introspection_rules
+    add_introspection_rules([], ["^oxdjango\.fields\.DictField"])
+    add_introspection_rules([], ["^oxdjango\.fields\.TupleField"])
+except:
+    pass