Pivot: Handle metas only

Author: VesnaT

Orange/widgets/data/owpivot.py

@@ -921,8 +921,8 @@ def init_attr_values(self):
             self.row_feature = model[0]
         model = self.controls.val_feature.model()
         if model and len(model) > 2:
-            self.val_feature = domain.variables[0] \
-                if domain.variables[0] in model else model[2]
+            allvars = domain.variables + domain.metas
+            self.val_feature = allvars[0] if allvars[0] in model else model[2]
 
     def commit(self):
         def send_outputs(pivot_table, filtered_data, grouped_data):

Orange/widgets/data/tests/test_owpivot.py

@@ -278,6 +278,14 @@ def test_table_values(self):
         self.assertEqual(model.data(model.index(4, 4)), "114.0")
         self.assertEqual(model.data(model.index(5, 4)), "reversable defect")
 
+    def test_only_metas_table(self):
+        self.send_signal(self.widget.Inputs.data, self.zoo[:, 17:])
+        self.assertTrue(self.widget.Warning.no_variables.is_shown())
+
+        data = self.zoo.transform(Domain([], metas=self.zoo.domain.attributes))
+        self.send_signal(self.widget.Inputs.data, data)
+        self.assertFalse(self.widget.Warning.no_variables.is_shown())
+
     def test_empty_table(self):
         data = self.heart_disease[:, :0]
         self.send_signal(self.widget.Inputs.data, data)