#-----------------------------------------------------------------------------
# Copyright (c) 2012 - 2022, Anaconda, Inc., and Bokeh Contributors.
# All rights reserved.
#
# The full license is in the file LICENSE.txt, distributed with this software.
#-----------------------------------------------------------------------------
''' Provide utility functions for implementing the ``bokeh`` command.
'''
#-----------------------------------------------------------------------------
# Boilerplate
#-----------------------------------------------------------------------------
from __future__ import annotations
import logging # isort:skip
log = logging.getLogger(__name__)
#-----------------------------------------------------------------------------
# Imports
#-----------------------------------------------------------------------------
# Standard library imports
import contextlib
import errno
import os
import sys
from typing import Iterator
# Bokeh imports
from bokeh.application import Application
from bokeh.application.handlers import (
DirectoryHandler,
Handler,
NotebookHandler,
ScriptHandler,
)
from bokeh.util.warnings import warn
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# Globals and constants
#-----------------------------------------------------------------------------
__all__ = (
'build_single_handler_application',
'build_single_handler_applications',
'die',
'report_server_init_errors',
)
#-----------------------------------------------------------------------------
# General API
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[docs]def die(message: str, status: int = 1) -> None:
''' Print an error message and exit.
This function will call ``sys.exit`` with the given ``status`` and the
process will terminate.
Args:
message (str) : error message to print
status (int) : the exit status to pass to ``sys.exit``
'''
print(message, file=sys.stderr)
sys.exit(status)
DIRSTYLE_MAIN_WARNING = """
It looks like you might be running the main.py of a directory app directly.
If this is the case, to enable the features of directory style apps, you must
call "bokeh serve" on the directory instead. For example:
bokeh serve my_app_dir/
If this is not the case, renaming main.py will suppress this warning.
"""
[docs]def build_single_handler_application(path: str, argv: list[str] | None = None) -> Application:
''' Return a Bokeh application built using a single handler for a script,
notebook, or directory.
In general a Bokeh :class:`~bokeh.application.application.Application` may
have any number of handlers to initialize |Document| objects for new client
sessions. However, in many cases only a single handler is needed. This
function examines the ``path`` provided, and returns an ``Application``
initialized with one of the following handlers:
* :class:`~bokeh.application.handlers.script.ScriptHandler` when ``path``
is to a ``.py`` script.
* :class:`~bokeh.application.handlers.notebook.NotebookHandler` when
``path`` is to an ``.ipynb`` Jupyter notebook.
* :class:`~bokeh.application.handlers.directory.DirectoryHandler` when
``path`` is to a directory containing a ``main.py`` script.
Args:
path (str) : path to a file or directory for creating a Bokeh
application.
argv (seq[str], optional) : command line arguments to pass to the
application handler
Returns:
:class:`~bokeh.application.application.Application`
Raises:
RuntimeError
Notes:
If ``path`` ends with a file ``main.py`` then a warning will be printed
regarding running directory-style apps by passing the directory instead.
'''
argv = argv or []
path = os.path.abspath(os.path.expanduser(path))
handler: Handler
# There are certainly race conditions here if the file/directory is deleted
# in between the isdir/isfile tests and subsequent code. But it would be a
# failure if they were not there to begin with, too (just a different error)
if os.path.isdir(path):
handler = DirectoryHandler(filename=path, argv=argv)
elif os.path.isfile(path):
if path.endswith(".ipynb"):
handler = NotebookHandler(filename=path, argv=argv)
elif path.endswith(".py"):
if path.endswith("main.py"):
warn(DIRSTYLE_MAIN_WARNING)
handler = ScriptHandler(filename=path, argv=argv)
else:
raise ValueError("Expected a '.py' script or '.ipynb' notebook, got: '%s'" % path)
else:
raise ValueError("Path for Bokeh server application does not exist: %s" % path)
if handler.failed:
raise RuntimeError("Error loading %s:\n\n%s\n%s " % (path, handler.error, handler.error_detail))
application = Application(handler)
return application
[docs]def build_single_handler_applications(paths: list[str], argvs: dict[str, list[str]] | None = None) -> dict[str, Application]:
''' Return a dictionary mapping routes to Bokeh applications built using
single handlers, for specified files or directories.
This function iterates over ``paths`` and ``argvs`` and calls
:func:`~bokeh.command.util.build_single_handler_application` on each
to generate the mapping.
Args:
paths (seq[str]) : paths to files or directories for creating Bokeh
applications.
argvs (dict[str, list[str]], optional) : mapping of paths to command
line arguments to pass to the handler for each path
Returns:
dict[str, Application]
Raises:
RuntimeError
'''
applications: dict[str, Application] = {}
argvs = argvs or {}
for path in paths:
application = build_single_handler_application(path, argvs.get(path, []))
route = application.handlers[0].url_path()
if not route:
if '/' in applications:
raise RuntimeError("Don't know the URL path to use for %s" % (path))
route = '/'
applications[route] = application
return applications
[docs]@contextlib.contextmanager
def report_server_init_errors(address: str | None = None, port: int | None = None, **kwargs: str) -> Iterator[None]:
''' A context manager to help print more informative error messages when a
``Server`` cannot be started due to a network problem.
Args:
address (str) : network address that the server will be listening on
port (int) : network address that the server will be listening on
Example:
.. code-block:: python
with report_server_init_errors(**server_kwargs):
server = Server(applications, **server_kwargs)
If there are any errors (e.g. port or address in already in use) then a
critical error will be logged and the process will terminate with a
call to ``sys.exit(1)``
'''
try:
yield
except OSError as e:
if e.errno == errno.EADDRINUSE:
log.critical("Cannot start Bokeh server, port %s is already in use", port)
elif e.errno == errno.EADDRNOTAVAIL:
log.critical("Cannot start Bokeh server, address '%s' not available", address)
else:
codename = errno.errorcode[e.errno]
log.critical("Cannot start Bokeh server [%s]: %r", codename, e)
sys.exit(1)
#-----------------------------------------------------------------------------
# Dev API
#-----------------------------------------------------------------------------
#-----------------------------------------------------------------------------
# Private API
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#-----------------------------------------------------------------------------
# Code
#-----------------------------------------------------------------------------