class_docstr: A dropdown button.
  
      
docstr: Set up a JavaScript handler for button or menu item clicks. 
docstr_tok: ["Set","up","a","JavaScript","handler","for","button","or","menu","item","clicks","."]
code: def js_on_click(self, handler: Callback) -> None:
      """Set up a JavaScript handler for button or menu item clicks."""
      self.js_on_event(ButtonClick, handler)
      self.js_on_event(MenuItemClick, handler)
  
imports: from __future__ import annotations
  import logging
  from typing import TYPE_CHECKING, Callable
  from ...core.enums import ButtonType
  from ...core.has_props import HasProps, abstract
  from ...core.properties import Bool, Either, Enum, Instance, List, Nullable, Override, Required, String, Tuple
  from ...events import ButtonClick, MenuItemClick
  from ..callbacks import Callback
  from ..ui.icons import BuiltinIcon, Icon
  from ..ui.tooltips import Tooltip
  from .widget import Widget
label_desc: Use image node_id 3 for calling the Dropdown obj's underlying member method code with example usage: obj.js_on_click(handler) without return types