+from django.utils.translation import ugettext_lazy as _
+
+
+class JSONEncoder(json.JSONEncoder):
+ def default(self, obj):
+ if isinstance(obj, datetime.datetime):
+ return obj.strftime('%Y-%m-%d %H:%M:%S')
+ elif isinstance(obj, datetime.date):
+ return obj.strftime('%Y-%m-%d')
+ elif isinstance(obj, datetime.time):
+ return obj.strftime('%H:%M:%S')
+ return json.JSONEncoder.default(self, obj)
+
+
+def dumps(data):
+ return JSONEncoder().encode(data)
+
+
+def loads(str):
+ return json.loads(str, encoding=settings.DEFAULT_CHARSET)
+
+
+class JSONFormField(forms.CharField):
+ widget = forms.Textarea
+
+ def clean(self, value):
+ try:
+ loads(value)
+ return value
+ except ValueError, e:
+ raise forms.ValidationError(_('Enter a valid JSON value. Error: %s') % e)
+
+
+class JSONField(models.TextField):
+ def formfield(self, **kwargs):
+ defaults = {'form_class': JSONFormField}
+ defaults.update(kwargs)
+ return super(JSONField, self).formfield(**defaults)
+
+ def db_type(self, connection):
+ return 'text'
+
+ def get_internal_type(self):
+ return 'TextField'
+
+ def contribute_to_class(self, cls, name):
+ super(JSONField, self).contribute_to_class(cls, name)
+
+ def get_value(model_instance):
+ return loads(getattr(model_instance, self.attname, None))
+ setattr(cls, 'get_%s_value' % self.name, get_value)
+
+ def set_value(model_instance, json):
+ return setattr(model_instance, self.attname, dumps(json))
+ setattr(cls, 'set_%s_value' % self.name, set_value)