fix: add "is false or null" grid filter, for nullable bool columns

src/wuttaweb/grids/filters.py

@@ -116,20 +116,22 @@ class GridFilter:
         'is_any':               "is any",
         'equal':                "equal to",
         'not_equal':            "not equal to",
-        'is_null':              "is null",
-        'is_not_null':          "is not null",
         'is_true':              "is true",
         'is_false':             "is false",
+        'is_false_null':        "is false or null",
+        'is_null':              "is null",
+        'is_not_null':          "is not null",
         'contains':             "contains",
         'does_not_contain':     "does not contain",
     }
 
     valueless_verbs = [
         'is_any',
-        'is_null',
-        'is_not_null',
         'is_true',
         'is_false',
+        'is_false_null',
+        'is_null',
+        'is_not_null',
     ]
 
     def __init__(
@@ -416,6 +418,27 @@ class BooleanAlchemyFilter(AlchemyFilter):
     """
     default_verbs = ['is_true', 'is_false']
 
+    def get_verbs(self):
+        """ """
+
+        # get basic verbs from caller, or default list
+        verbs = getattr(self, 'verbs', self.default_verbs)
+        if callable(verbs):
+            verbs = verbs()
+        verbs = list(verbs)
+
+        # add some more if column is nullable
+        if self.nullable:
+            for verb in ('is_false_null', 'is_null', 'is_not_null'):
+                if verb not in verbs:
+                    verbs.append(verb)
+
+        # add wildcard
+        if 'is_any' not in verbs:
+            verbs.append('is_any')
+
+        return verbs
+
     def coerce_value(self, value):
         """ """
         if value is not None:
@@ -435,6 +458,14 @@ class BooleanAlchemyFilter(AlchemyFilter):
         """
         return query.filter(self.model_property == False)
 
+    def filter_is_false_null(self, query, value):
+        """
+        Filter data with "is false or null" condition.  The value is
+        ignored.
+        """
+        return query.filter(sa.or_(self.model_property == False,
+                                   self.model_property == None))
+
 
 default_sqlalchemy_filters = {
     None: AlchemyFilter,

tests/grids/test_filters.py

@@ -328,9 +328,15 @@ class TestBooleanAlchemyFilter(WebTestCase):
 
         model = self.app.model
         self.sample_data = [
-            {'username': 'alice', 'active': True},
-            {'username': 'bob', 'active': True},
-            {'username': 'charlie', 'active': False},
+            {'username': 'alice',
+             'prevent_edit': False,
+             'active': True},
+            {'username': 'bob',
+             'prevent_edit': True,
+             'active': True},
+            {'username': 'charlie',
+             'active': False,
+             'prevent_edit': None},
         ]
         for user in self.sample_data:
             user = model.User(**user)
@@ -343,6 +349,34 @@ class TestBooleanAlchemyFilter(WebTestCase):
         kwargs['model_property'] = model_property
         return factory(self.request, model_property.key, **kwargs)
 
+    def test_get_verbs(self):
+        model = self.app.model
+
+        # bool field, not nullable
+        filtr = self.make_filter(model.User.active,
+                                 factory=mod.BooleanAlchemyFilter,
+                                 nullable=False)
+        self.assertFalse(hasattr(filtr, 'verbs'))
+        self.assertEqual(filtr.default_verbs, ['is_true', 'is_false'])
+
+        # by default, returns default verbs (plus 'is_any')
+        self.assertEqual(filtr.get_verbs(), ['is_true', 'is_false', 'is_any'])
+
+        # default verbs can be a callable
+        filtr.default_verbs = lambda: ['foo', 'bar']
+        self.assertEqual(filtr.get_verbs(), ['foo', 'bar', 'is_any'])
+
+        # bool field, *nullable*
+        filtr = self.make_filter(model.User.active,
+                                 factory=mod.BooleanAlchemyFilter,
+                                 nullable=True)
+        self.assertFalse(hasattr(filtr, 'verbs'))
+        self.assertEqual(filtr.default_verbs, ['is_true', 'is_false'])
+
+        # effective verbs also include is_false_null
+        self.assertEqual(filtr.get_verbs(), ['is_true', 'is_false', 'is_false_null',
+                                             'is_null', 'is_not_null', 'is_any'])
+
     def test_coerce_value(self):
         model = self.app.model
         filtr = self.make_filter(model.User.active)
@@ -377,6 +411,16 @@ class TestBooleanAlchemyFilter(WebTestCase):
         self.assertIsNot(filtered_query, self.sample_query)
         self.assertEqual(filtered_query.count(), 1)
 
+    def test_filter_is_false_null(self):
+        model = self.app.model
+        filtr = self.make_filter(model.User.prevent_edit)
+        self.assertEqual(self.sample_query.count(), 3)
+
+        # nb. only one account is marked with "prevent edit"
+        filtered_query = filtr.filter_is_false_null(self.sample_query, None)
+        self.assertIsNot(filtered_query, self.sample_query)
+        self.assertEqual(filtered_query.count(), 2)
+
 
 class TestVerbNotSupported(TestCase):