Merge pull request #5102 from jescalada/ipywidgets-integration-fix

Fix widget initialization issue in v6

Author: marthacryan

CHANGELOG.md

@@ -2,6 +2,11 @@
 All notable changes to this project will be documented in this file.
 This project adheres to [Semantic Versioning](http://semver.org/).
 
+## Unreleased
+
+### Fixed
+- Fix third-party widget display issues in v6 [[#5102]https://github.com/plotly/plotly.py/pull/5102]
+
 ## [6.0.1] - 2025-03-14
 
 ### Updated

plotly/basewidget.py

@@ -142,6 +142,11 @@ def __init__(
         # views of this widget
         self._view_count = 0
 
+        # Initialize widget layout and data for third-party widget integration
+        # --------------------------------------------------------------------
+        self._widget_layout = deepcopy(self._layout_obj._props)
+        self._widget_data = deepcopy(self._data)
+
     def show(self, *args, **kwargs):
         return self
 

tests/test_core/test_figure_widget_backend/test_validate_initialization.py

@@ -0,0 +1,21 @@
+from unittest import TestCase
+import plotly.graph_objs as go
+import pytest
+
+try:
+    go.FigureWidget()
+    figure_widget_available = True
+except ImportError:
+    figure_widget_available = False
+
+
+class TestInitialization(TestCase):
+    if figure_widget_available:
+
+        def test_widget_layout_present_on_init(self):
+            fig = go.FigureWidget(data=go.Scatter(x=[1, 2], y=[1, 2]))
+            assert fig._widget_layout != {}
+
+        def test_widget_data_present_on_init(self):
+            fig = go.FigureWidget(data=go.Bar(x=[1, 2], y=[1, 2]))
+            assert fig._widget_data != []