Source code for

# Copyright (c) 2012 - 2024, Anaconda, Inc., and Bokeh Contributors.
# All rights reserved.
# The full license is in the file LICENSE.txt, distributed with this software.
'''  Provide a Bokeh Application Handler to build up documents by running
the code from ```` or ``main.ipynb`` files in specified directories.

The directory may also optionally contain:

* A ```` module to provide lifecycle callbacks for the
  application and sessions.

* A ``static`` subdirectory containing app-specific static resources to

* A ``theme.yaml`` file containing a Bokeh theme to automatically apply to
  all new documents.

* A ``templates`` subdirectory containing templates for app display

A full directory layout might look like:

.. code-block:: none



# Boilerplate
from __future__ import annotations

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

# Imports

# Standard library imports
import sys
from os.path import (
from types import ModuleType
from typing import TYPE_CHECKING, Any, Coroutine

# External imports
from jinja2 import Environment, FileSystemLoader, Template

# Bokeh imports
from ...core.types import PathLike
from ...document import Document
from ..application import ServerContext, SessionContext
from .code_runner import CodeRunner
from .handler import Handler
from .notebook import NotebookHandler
from .script import ScriptHandler
from .server_lifecycle import ServerLifecycleHandler
from .server_request_handler import ServerRequestHandler

    from tornado.httputil import HTTPServerRequest

    from ...themes import Theme

# Globals and constants

__all__ = (

# General API

# Dev API

[docs] class DirectoryHandler(Handler): ''' Load an application directory which modifies a Document. ''' _package_runner: CodeRunner | None _package: ModuleType | None _lifecycle_handler: Handler _request_handler: Handler _theme: Theme | None _static: str | None _template: Template | None
[docs] def __init__(self, *, filename: PathLike, argv: list[str] = []) -> None: ''' Keywords: filename (str) : a path to an application directory with either "" or "main.ipynb" argv (list[str], optional) : a list of string arguments to make available as sys.argv to ''' super().__init__() src_path = filename init_py = join(src_path, '') if exists(init_py): with open(init_py, encoding="utf8") as init_py_f: self._package_runner = CodeRunner(, init_py, argv) self._package = self._package_runner.new_module() assert self._package is not None sys.modules[self._package.__name__] = self._package else: self._package_runner = None self._package = None main_py = join(src_path, '') main_ipy = join(src_path, 'main.ipynb') if exists(main_py) and exists(main_ipy): log.warning(f"Found both '' and 'main.ipynb' in {src_path}, using ''") main = main_py elif exists(main_py): main = main_py elif exists(main_ipy): main = main_ipy else: raise ValueError(f"No '' or 'main.ipynb' in {src_path}") self._path = src_path self._main = main handler = NotebookHandler if main.endswith('.ipynb') else ScriptHandler self._main_handler = handler(filename=self._main, argv=argv, package=self._package) hooks = None app_hooks = join(src_path, '') lifecycle = join(src_path, '') if exists(app_hooks) and exists(lifecycle): raise ValueError("Directory style apps can provide either or, not both.") elif exists(lifecycle): hooks = lifecycle elif exists(app_hooks): hooks = app_hooks if hooks is not None: self._lifecycle_handler = ServerLifecycleHandler(filename=hooks, argv=argv, package=self._package) else: self._lifecycle_handler = Handler() # no-op handler if exists(app_hooks): assert hooks is not None self._request_handler = ServerRequestHandler(filename=hooks, argv=argv, package=self._package) else: self._request_handler = Handler() # no-op handler self._theme = None themeyaml = join(src_path, 'theme.yaml') if exists(themeyaml): from bokeh.themes import Theme self._theme = Theme(filename=themeyaml) appstatic = join(src_path, 'static') if exists(appstatic): self._static = appstatic self._template = None appindex = join(src_path, 'templates', 'index.html') if exists(appindex): env = Environment(loader=FileSystemLoader(dirname(appindex))) self._template = env.get_template('index.html')
# Properties -------------------------------------------------------------- @property def error(self) -> str | None: ''' If the handler fails, may contain a related error message. ''' return self._main_handler.error or self._lifecycle_handler.error @property def error_detail(self) -> str | None: ''' If the handler fails, may contain a traceback or other details. ''' return self._main_handler.error_detail or self._lifecycle_handler.error_detail @property def failed(self) -> bool: ''' ``True`` if the handler failed to modify the doc ''' return self._main_handler.failed or self._lifecycle_handler.failed @property def safe_to_fork(self) -> bool: ''' Whether it is still safe for the Bokeh server to fork new workers. ``False`` if the configured code (script, notebook, etc.) has already been run. ''' return self._main_handler.safe_to_fork # Public methods ----------------------------------------------------------
[docs] def modify_document(self, doc: Document) -> None: ''' Execute the configured ```` or ``main.ipynb`` to modify the document. This method will also search the app directory for any theme or template files, and automatically configure the document with them if they are found. ''' if self._lifecycle_handler.failed: return # Note: we do NOT copy self._theme, which assumes the Theme # class is immutable (has no setters) if self._theme is not None: doc.theme = self._theme if self._template is not None: doc.template = self._template # This internal handler should never add a template self._main_handler.modify_document(doc)
[docs] def on_server_loaded(self, server_context: ServerContext) -> None: ''' Execute `on_server_unloaded`` from ```` (if it is defined) when the server is first started. Args: server_context (ServerContext) : ''' if self._package_runner and self._package: return self._lifecycle_handler.on_server_loaded(server_context)
[docs] def on_server_unloaded(self, server_context: ServerContext) -> None: ''' Execute ``on_server_unloaded`` from ```` (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._lifecycle_handler.on_server_unloaded(server_context)
[docs] def on_session_created(self, session_context: SessionContext) -> Coroutine[Any, Any, None]: ''' Execute ``on_session_created`` from ```` (if it is defined) when a new session is created. Args: session_context (SessionContext) : ''' return self._lifecycle_handler.on_session_created(session_context)
[docs] def on_session_destroyed(self, session_context: SessionContext) -> Coroutine[Any, Any, None]: ''' Execute ``on_session_destroyed`` from ```` (if it is defined) when a session is destroyed. Args: session_context (SessionContext) : ''' return self._lifecycle_handler.on_session_destroyed(session_context)
[docs] def process_request(self, request: HTTPServerRequest) -> dict[str, Any]: ''' Processes incoming HTTP request returning a dictionary of additional data to add to the session_context. Args: request: HTTP request Returns: A dictionary of JSON serializable data to be included on the session context. ''' return self._request_handler.process_request(request)
[docs] def url_path(self) -> str | None: ''' The last path component for the basename of the path to the configured directory. ''' if self.failed: return None else: # TODO should fix invalid URL characters return '/' + basename(self._path)
#----------------------------------------------------------------------------- # Private API #----------------------------------------------------------------------------- #----------------------------------------------------------------------------- # Code #-----------------------------------------------------------------------------