#----------------------------------------------------------------------------- # Copyright (c) 2012 - 2020, Anaconda, Inc., and Bokeh Contributors. # All rights reserved. # # The full license is in the file LICENSE.txt, distributed with this software. #----------------------------------------------------------------------------- ''' Bokeh Application Handler to look for Bokeh server lifecycle callbacks in a specified Python module. ''' #----------------------------------------------------------------------------- # Boilerplate #----------------------------------------------------------------------------- import logging # isort:skip log = logging.getLogger(__name__) #----------------------------------------------------------------------------- # Imports #----------------------------------------------------------------------------- # Standard library imports import codecs import os # Bokeh imports from ...util.callback_manager import _check_callback from .code_runner import CodeRunner from .lifecycle import LifecycleHandler #----------------------------------------------------------------------------- # Globals and constants #----------------------------------------------------------------------------- __all__ = ( 'ServerLifecycleHandler', ) #----------------------------------------------------------------------------- # General API #----------------------------------------------------------------------------- #----------------------------------------------------------------------------- # Dev API #----------------------------------------------------------------------------- [docs]class ServerLifecycleHandler(LifecycleHandler): ''' Load a script which contains server lifecycle callbacks. ''' [docs] def __init__(self, *args, **kwargs): ''' Keyword Args: filename (str) : path to a module to load lifecycle callbacks from argv (list[str], optional) : a list of string arguments to use as ``sys.argv`` when the callback code is executed. (default: []) ''' super().__init__(*args, **kwargs) if 'filename' not in kwargs: raise ValueError('Must pass a filename to ServerLifecycleHandler') filename = kwargs['filename'] argv = kwargs.get('argv', []) package = kwargs.get('package', False) source = codecs.open(filename, 'r', 'UTF-8').read() self._runner = CodeRunner(source, filename, argv, package=package) if not self._runner.failed: # unlike ScriptHandler, we only load the module one time self._module = self._runner.new_module() def extract_callbacks(): contents = self._module.__dict__ if 'on_server_loaded' in contents: self._on_server_loaded = contents['on_server_loaded'] if 'on_server_unloaded' in contents: self._on_server_unloaded = contents['on_server_unloaded'] if 'on_session_created' in contents: self._on_session_created = contents['on_session_created'] if 'on_session_destroyed' in contents: self._on_session_destroyed = contents['on_session_destroyed'] _check_callback(self._on_server_loaded, ('server_context',), what="on_server_loaded") _check_callback(self._on_server_unloaded, ('server_context',), what="on_server_unloaded") _check_callback(self._on_session_created, ('session_context',), what="on_session_created") _check_callback(self._on_session_destroyed, ('session_context',), what="on_session_destroyed") self._runner.run(self._module, extract_callbacks) # Properties -------------------------------------------------------------- @property def error(self): ''' If the handler fails, may contain a related error message. ''' return self._runner.error @property def error_detail(self): ''' If the handler fails, may contain a traceback or other details. ''' return self._runner.error_detail @property def failed(self): ''' ``True`` if the lifecycle callbacks failed to execute ''' return self._runner.failed # Public methods ---------------------------------------------------------- [docs] def url_path(self): ''' The last path component for the basename of the path to the callback module. ''' if self.failed: return None else: # TODO should fix invalid URL characters return '/' + os.path.splitext(os.path.basename(self._runner.path))[0] #----------------------------------------------------------------------------- # Private API #----------------------------------------------------------------------------- #----------------------------------------------------------------------------- # Code #-----------------------------------------------------------------------------