Don't attempt to display/render non-DOMWidget (i.e., Widget) objects (#134)

Author: cpsievert

CHANGELOG.md

@@ -5,6 +5,10 @@ All notable changes to shinywidgets will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [UNRELEASED]
+
+* `@render_widget` now works properly with `Widget`s that aren't `DOMWidget`s (i.e., widgets that aren't meant to be displayed directly). As a result, you can now use `@render_widget` to gain a reference to the widget instance, and then use that reference to update the widget's value. (#133)
+
 ## [0.3.0] - 2024-01-25
 
 * The `@render_widget` decorator now attaches a `widget` (and `value`) attribute to the function it decorates. This allows for easier access to the widget instance (or value), and eliminates the need for `register_widget` (which is now soft deprecated).  (#119)

shinywidgets/__init__.py

@@ -1,8 +1,8 @@
 """Top-level package for shinywidgets."""
 
 __author__ = """Carson Sievert"""
-__email__ = "carson@rstudio.com"
-__version__ = "0.3.0"
+__email__ = "carson@posit.co"
+__version__ = "0.3.0.9000"
 
 from ._as_widget import as_widget
 from ._dependencies import bokeh_dependency

shinywidgets/_render_widget_base.py

@@ -89,6 +89,10 @@ async def render(self) -> Jsonifiable | None:
 
         self._widget = cast(WidgetT, widget)
 
+        # Don't actually display anything unless this is a DOMWidget
+        if not isinstance(widget, DOMWidget):
+            return None
+
         return {
             "model_id": str(
                 cast(