fix: add get_effective_rows() method for batch handler

src/wuttjamaican/batch.py

@@ -416,6 +416,19 @@ class BatchHandler(GenericHandler):
         :returns: Markdown text describing batch execution.
         """
 
+    def get_effective_rows(self, batch):
+        """
+        This should return a list of "effective" rows for the batch.
+
+        In other words, which rows should be "acted upon" when the
+        batch is executed.
+
+        The default logic returns the full list of batch
+        :attr:`~wuttjamaican.db.model.batch.BatchMixin.rows`, but
+        subclass may need to filter by status code etc.
+        """
+        return batch.rows
+
     def do_execute(self, batch, user, progress=None, **kwargs):
         """
         Perform the execution steps for a batch.

tests/test_batch.py

@@ -130,6 +130,26 @@ else:
             self.session.flush()
             self.assertEqual(batch.row_count, 0)
 
+        def test_get_effective_rows(self):
+            model = self.app.model
+            handler = self.make_handler()
+
+            user = model.User(username='barney')
+            self.session.add(user)
+            batch = handler.make_batch(self.session, created_by=user)
+            self.session.add(batch)
+            self.session.flush()
+
+            self.assertEqual(handler.get_effective_rows(batch), [])
+
+            row = handler.make_row()
+            handler.add_row(batch, row)
+            self.session.flush()
+
+            rows = handler.get_effective_rows(batch)
+            self.assertEqual(len(rows), 1)
+            self.assertIs(rows[0], row)
+
         def test_do_execute(self):
             model = self.app.model
             user = model.User(username='barney')