Add message into css_classes to ChatMessage's markup

panel/chat/message.py

@@ -471,13 +471,33 @@ def _select_renderer(
  return contents, renderer
 
  def _include_stylesheets_inplace(self, obj):
+ if hasattr(obj, "objects"):
+ obj.objects[:] = [
+ self._include_stylesheets_inplace(o) for o in obj.objects
+ ]
+ else:
+ obj = _panel(obj)
  obj.stylesheets = [
  stylesheet for stylesheet in self._stylesheets + self.stylesheets
  if stylesheet not in obj.stylesheets
  ] + obj.stylesheets
+ return obj
+
+ def _include_message_css_class_inplace(self, obj):
  if hasattr(obj, "objects"):
- for o in obj.objects:
- self._include_stylesheets_inplace(o)
+ obj.objects[:] = [
+ self._include_message_css_class_inplace(o)
+ for o in obj.objects
+ ]
+ else:
+ obj = _panel(obj)
+ is_markup = isinstance(obj, HTMLBasePane) and not isinstance(obj, FileBase)
+ if obj.css_classes or not is_markup:
+ return obj
+ if len(str(obj.object)) > 0: # only show a background if there is content
+ obj.css_classes = [*(css for css in obj.css_classes if css != "message"), "message"]
+ obj.sizing_mode = None
+ return obj
 
  def _set_params(self, obj, **params):
  """
@@ -486,9 +506,7 @@ def _set_params(self, obj, **params):
  self._include_stylesheets_inplace(obj)
  is_markup = isinstance(obj, HTMLBasePane) and not isinstance(obj, FileBase)
  if is_markup:
- if len(str(obj.object)) > 0: # only show a background if there is content
- params['css_classes'] = [*(css for css in obj.css_classes if css != "message"), "message"]
- params['sizing_mode'] = None
+ self._include_message_css_class_inplace(obj)
  else:
  if obj.sizing_mode is None and not obj.width:
  params['sizing_mode'] = "stretch_width"
@@ -508,6 +526,7 @@ def _create_panel(self, value, old=None):
  if isinstance(value, Viewable):
  self._internal = False
  self._include_stylesheets_inplace(value)
+ self._include_message_css_class_inplace(value)
  return value
 
  renderer = None

panel/tests/chat/test_message.py

@@ -214,6 +214,27 @@ def test_include_stylesheets_inplace_on_layouts(self):
  assert message.object.stylesheets == ChatMessage._stylesheets + ["chat.css", "row.css"]
  assert message.object.objects[0].stylesheets == ChatMessage._stylesheets + ["chat.css", "row2.css"]
 
+ def test_include_message_css_class_inplace(self):
+ # markdown
+ message = ChatMessage(object=Markdown("hello"))
+ assert message.object.css_classes == ["message"]
+
+ # custom css class; no message appended
+ message = ChatMessage(object=Markdown("hello", css_classes=["custom"]))
+ assert message.object.css_classes == ["custom"]
+
+ # nested in layout; message appended
+ message = ChatMessage(object=Row(Markdown("hello")))
+ assert message.object.objects[0].css_classes == ["message"]
+
+ # nested in layout as a string; message appended
+ message = ChatMessage(object=Row("hello"))
+ assert message.object.objects[0].css_classes == ["message"]
+
+ # nested in layout with custom css; no message appended
+ message = ChatMessage(object=Row(Markdown("hello", css_classes=["custom"])))
+ assert message.object.objects[0].css_classes == ["custom"]
+
  @mpl_available
  def test_can_display_any_python_object_that_panel_can_display(self):
  # For example matplotlib figures