Source code for bokeh.application.handlers.server_lifecycle

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# Copyright (c) 2012 - 2019, Anaconda, Inc., and Bokeh Contributors.
# All rights reserved.
#
# The full license is in the file LICENSE.txt, distributed with this software.
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''' 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__)

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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 .lifecycle import LifecycleHandler

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# Globals and constants
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__all__ = (
    'ServerLifecycleHandler',
)

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# General API
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# Dev API
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[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(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) 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]
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