Fix DatetimeCol format option

flask_table/columns.py

@@ -174,9 +174,9 @@ class DatetimeCol(Col):
     output empty.
 
     """
-    def __init__(self, name, **kwargs):
+    def __init__(self, name, datetime_format='short', **kwargs):
         super(DatetimeCol, self).__init__(name, **kwargs)
-        self.datetime_format = kwargs.get('datetime_format', 'short')
+        self.datetime_format = datetime_format
 
     def td_format(self, content):
         if content:

tests/__init__.py

@@ -606,6 +606,23 @@ def test_one(self):
             'datetime_test', 'test_one', items)
 
 
+class DatetimeTestFormat(TableTest):
+    def setUp(self):
+
+        class MyTable(Table):
+            datetime = DatetimeCol(
+                'DateTime Heading',
+                datetime_format="YYYY-MM-dd hh:mm")
+        self.table_cls = MyTable
+
+    def test_one(self):
+        items = [
+            Item(datetime=datetime(2014, 1, 1, 10, 20, 30)),
+            Item(datetime=None)]
+        self.assert_html_equivalent_from_file(
+            'datetime_test_format', 'test_one', items)
+
+
 class EscapeTest(TableTest):
     def setUp(self):
 

tests/html/datetime_test_format/test_one.html

@@ -0,0 +1,9 @@
+<table>
+  <thead>
+    <tr><th>DateTime Heading</th></tr>
+  </thead>
+  <tbody>
+    <tr><td>2014-01-01 10:20</td></tr>
+    <tr><td></td></tr>
+  </tbody>
+</table>