From 0d6fdd4a78a17ebb2a734519ac769c0eb4d80d17 Mon Sep 17 00:00:00 2001
From: monsterlag <64719697+monsterlag@users.noreply.github.com>
Date: Thu, 22 Oct 2026 01:03:10 -0400
Subject: [PATCH] Make components always truthy

Component defined __len__ but not __bool__, so truthiness fell back to
the number of children and a component without children (or without a
children prop, like DataTable) was falsy. Fixes #2906.
---
 dash/development/base_component.py            |  5 +++++
 tests/unit/development/test_base_component.py | 10 +++++++++-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/dash/development/base_component.py b/dash/development/base_component.py
index b6798064e1..fb865312cd 100644
--- a/dash/development/base_component.py
+++ b/dash/development/base_component.py
@@ -433,6 +433,11 @@ def __iter__(self):
         for t in self._traverse_ids():
             yield t.id  # type: ignore[reportAttributeAccessIssue]
 
+    def __bool__(self):
+        # Without this, truthiness falls back to __len__, so a component
+        # with no children (or no children prop, like DataTable) is falsy.
+        return True
+
     def __len__(self):
         """Return the number of items in the tree."""
         # TODO - Should we return the number of items that have IDs
diff --git a/tests/unit/development/test_base_component.py b/tests/unit/development/test_base_component.py
index cefde04fde..a7ba6a2720 100644
--- a/tests/unit/development/test_base_component.py
+++ b/tests/unit/development/test_base_component.py
@@ -6,7 +6,7 @@
 from dash import __version__, Dash
 from dash import html
 from dash.development.base_component import Component
-from dash import dcc, Input, Output
+from dash import dcc, dash_table, Input, Output
 
 Component._prop_names = ("id", "a", "children", "style")
 Component._type = "TestComponent"
@@ -539,3 +539,11 @@ def update2(v):
 def test_debc030_invalid_children_args():
     with pytest.raises(TypeError):
         dcc.Input(children="invalid children")
+
+
+def test_debc031_bool_is_always_true():
+    assert bool(Component())
+    assert bool(Component(children=[]))
+    assert bool(html.Div())
+    assert bool(dash_table.DataTable(data=[{"a": 1}]))
+    assert (html.Div() or None) is not None