prevent Filter.is_active from false positives due to a default op bei…

…ng set (necessary values may not be provided for the filter to apply)

changelog.rst

@@ -4,7 +4,7 @@ Changelog
 0.1.32 released <in development>
 ==========================
 
- - ?
+ - corrected the results of Filter.is_active to account for default operation with no value
 
 0.1.31 released 2016-11-03
 ==========================

webgrid/filters.py

@@ -104,7 +104,10 @@ def __init__(self, sa_col, default_op=None, default_value1=None, default_value2=
 
     @property
     def is_active(self):
-        return self.op is not None and not self.error
+        operator_by_key = {op.key: op for op in self.operators}
+        return self.op is not None and not self.error and (
+            operator_by_key[self.op].field_type is None or self.value1 is not None
+        )
 
     @property
     def is_display_active(self):

webgrid/tests/test_filters.py

@@ -72,6 +72,7 @@ def test_doesnt_contain(self):
     def test_default(self):
         tf = TextFilter(Person.firstname, default_op='contains', default_value1='foo')
         tf.set(None, None)
+        assert tf.is_active
         query = tf.apply(db.session.query(Person.id))
         self.assert_in_query(query, "WHERE persons.firstname LIKE '%foo%'")
 
@@ -80,6 +81,7 @@ def def_op():
             return 'contains'
         tf = TextFilter(Person.firstname, default_op=def_op, default_value1='bar')
         tf.set(None, None)
+        assert tf.is_active
         query = tf.apply(db.session.query(Person.id))
         self.assert_in_query(query, "WHERE persons.firstname LIKE '%bar%'")
 
@@ -88,9 +90,15 @@ def def_val():
             return 'bar'
         tf = TextFilter(Person.firstname, default_op='contains', default_value1=def_val)
         tf.set(None, None)
+        assert tf.is_active
         query = tf.apply(db.session.query(Person.id))
         self.assert_in_query(query, "WHERE persons.firstname LIKE '%bar%'")
 
+    def test_default_no_value(self):
+        tf = TextFilter(Person.firstname, default_op='contains')
+        tf.set(None, None)
+        assert not tf.is_active
+
 
 class TestTextFilterWithCaseSensitiveDialect(CheckFilterBase):
     def get_filter(self):