From 5ee008025addae18d87f542b4fc25b32dc52ec28 Mon Sep 17 00:00:00 2001
From: Michael Elsdoerfer <michael@elsdoerfer.com>
Date: Tue, 6 Apr 2010 15:18:00 +0200
Subject: [PATCH] Added a __len__ method to the columns container.

---
 django_tables/base.py | 4 ++++
 tests/test_basic.py   | 9 +++++++++
 2 files changed, 13 insertions(+)

diff --git a/django_tables/base.py b/django_tables/base.py
index bdb97bb..d005226 100644
--- a/django_tables/base.py
+++ b/django_tables/base.py
@@ -249,6 +249,10 @@ class Columns(object):
         else:
             return item in self.all()
 
+    def __len__(self):
+        self._spawn_columns()
+        return len([1 for c in self._columns.values() if c.visible])
+
     def __getitem__(self, name):
         """Return a column by name."""
         self._spawn_columns()
diff --git a/tests/test_basic.py b/tests/test_basic.py
index d171bd0..fe94278 100644
--- a/tests/test_basic.py
+++ b/tests/test_basic.py
@@ -53,6 +53,15 @@ def test_declaration():
     assert 'motto' in StateTable2.base_columns
 
 
+def test_column_count():
+    class MyTable(TestTable):
+        visbible = tables.Column(visible=True)
+        hidden = tables.Column(visible=False)
+
+    # The columns container supports the len() builtin
+    assert len(MyTable([]).columns) == 1
+
+
 def test_pagination():
     class BookTable(TestTable):
         name = tables.Column()
-- 
2.26.2