plugin.py

from pluginlib import Parent

# Plugin Template

@Parent("Plugin")
class PluginTemplate(object):
  ''' Plugin Template '''

  m_ui = None

  def attach_ui(self, ui):
    self.m_ui = ui

  def on_open(self, ws): 
    return

  def on_close(self, ws, close_status_code, close_msg): 
    return

  def on_error(self, ws, error): 
    return

  def on_recv(self, ws, data, type, continuous): 
    return

  def on_send(self, ws, data, opcode): 
    return

  def on_ping(self, ws, message): 
    return

  def on_pong(self, ws, message): 
    return

# Plugin Manager

from pluginlib import PluginLoader, PluginImportError

_plugins = None

def plugins():
  global _plugins
  return [] if _plugins is None else _plugins.Plugin.values()

def initialize(ui):
  global _plugins
  if _plugins is None:
    loader = PluginLoader(modules=["plugins"])
    try:
      _plugins = loader.plugins
    except PluginImportError as e:
      print(e)
    for e in plugins():
      e.attach_ui(e, ui)