Source code for bokeh.command.util

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# 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.
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''' Provide utility functions for implementing the ``bokeh`` command.

'''
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# Boilerplate
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from __future__ import annotations

import logging # isort:skip
log = logging.getLogger(__name__)

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# Imports
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# Standard library imports
import contextlib
import errno
import os
import sys
import warnings
from typing import Iterator

# Bokeh imports
from bokeh.application import Application
from bokeh.application.handlers import (
    DirectoryHandler,
    Handler,
    NotebookHandler,
    ScriptHandler,
)

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# Globals and constants
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__all__ = (
    'build_single_handler_application',
    'build_single_handler_applications',
    'die',
    'report_server_init_errors',
)

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# 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"): warnings.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)
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