def test_prep_value_correct_values_json(self):
     w = JSignatureWidget()
     val = [{"x": [1, 2], "y": [3, 4]}]
     val_str = '[{"x":[1,2], "y":[3,4]}]'
     val_prep = w.prep_value(val_str)
     self.assertIsInstance(val_prep, six.string_types)
     self.assertEquals(val, json.loads(val_prep))
 def test_prep_value_empty_values(self):
     w = JSignatureWidget()
     for val in ['', [], '[]']:
         self.assertEqual('[]', w.prep_value(val))