Source code for bokeh.application.handlers.server_lifecycle

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# Copyright (c) 2012 - 2017, Anaconda, Inc. All rights reserved.
#
# Powered by the Bokeh Development Team.
#
# 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.

'''

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# Boilerplate
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from __future__ import absolute_import, division, print_function, unicode_literals

import logging
log = logging.getLogger(__name__)

from bokeh.util.api import general, dev ; general, dev

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# Imports
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# Standard library imports
import codecs
import os

# External imports

# Bokeh imports
from ...util.callback_manager import _check_callback
from .code_runner import CodeRunner
from .handler import Handler

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# Globals and constants
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# General API
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@general((1,0,0))
[docs]class ServerLifecycleHandler(Handler): ''' 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(ServerLifecycleHandler, self).__init__(*args, **kwargs) if 'filename' not in kwargs: raise ValueError('Must pass a filename to ServerLifecycleHandler') filename = kwargs['filename'] argv = kwargs.get('argv', []) source = codecs.open(filename, 'r', 'UTF-8').read() self._runner = CodeRunner(source, filename, argv) self._on_server_loaded = _do_nothing self._on_server_unloaded = _do_nothing self._on_session_created = _do_nothing self._on_session_destroyed = _do_nothing 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 @general((1,0,0)) def error(self): ''' If the handler fails, may contain a related error message. ''' return self._runner.error @property @general((1,0,0)) def error_detail(self): ''' If the handler fails, may contain a traceback or other details. ''' return self._runner.error_detail @property @general((1,0,0)) def failed(self): ''' ``True`` if the lifecycle callbacks failed to execute ''' return self._runner.failed # Public methods ---------------------------------------------------------- @general((1,0,0))
[docs] def modify_document(self, doc): ''' This handler does not make any modifications to the Document. Args: doc (Document) : A Bokeh Document to update in-place *This handler does not modify the document* Returns: None ''' # we could support a modify_document function, might be weird though. pass
@general((1,0,0))
[docs] def on_server_loaded(self, server_context): ''' Execute `on_server_unloaded`` from the configured module (if it is defined) when the server is first started. Args: server_context (ServerContext) : ''' return self._on_server_loaded(server_context)
@general((1,0,0))
[docs] def on_server_unloaded(self, server_context): ''' Execute ``on_server_unloaded`` from the configured module (if it is defined) when the server cleanly exits. (Before stopping the server's ``IOLoop``.) Args: server_context (ServerContext) : .. warning:: In practice this code may not run, since servers are often killed by a signal. ''' return self._on_server_unloaded(server_context)
@general((1,0,0))
[docs] def on_session_created(self, session_context): ''' Execute ``on_session_created`` from the configured module (if it is defined) when a new session is created. Args: session_context (SessionContext) : ''' return self._on_session_created(session_context)
@general((1,0,0))
[docs] def on_session_destroyed(self, session_context): ''' Execute ``on_session_destroyed`` from the configured module (if it is defined) when a new session is destroyed. Args: session_context (SessionContext) : ''' return self._on_session_destroyed(session_context)
@general((1,0,0))
[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]
#----------------------------------------------------------------------------- # Dev API #----------------------------------------------------------------------------- #----------------------------------------------------------------------------- # Private API #----------------------------------------------------------------------------- def _do_nothing(ignored): pass #----------------------------------------------------------------------------- # Code #-----------------------------------------------------------------------------