File: C:/Users/fred/anaconda3/Lib/site-packages/panel/io/state.py
"""
Various utilities for recording and embedding state in a rendered app.
"""
from __future__ import annotations
import asyncio
import datetime as dt
import inspect
import logging
import os
import shutil
import sys
import threading
import time
from collections import Counter, defaultdict
from collections.abc import Iterator
from contextlib import contextmanager, suppress
from contextvars import ContextVar
from functools import partial, wraps
from typing import (
TYPE_CHECKING, Any, Awaitable, Callable, ClassVar, Coroutine,
Iterator as TIterator, Literal, Optional, TypeVar, Union,
)
from urllib.parse import urljoin
from weakref import WeakKeyDictionary
import param
from bokeh.document import Document
from bokeh.document.locking import UnlockedDocumentProxy
from bokeh.io import curdoc as _curdoc
from pyviz_comms import CommManager as _CommManager
from ..util import decode_token, parse_timedelta
from .logging import LOG_SESSION_RENDERED, LOG_USER_MSG
_state_logger = logging.getLogger('panel.state')
if TYPE_CHECKING:
from concurrent.futures import Future
from bokeh.model import Model
from bokeh.models import ImportedStyleSheet
from bokeh.server.contexts import BokehSessionContext
from bokeh.server.server import Server
from IPython.display import DisplayHandle
from pyviz_comms import Comm
from tornado.ioloop import IOLoop
from ..template.base import BaseTemplate
from ..viewable import Viewable
from ..widgets.indicators import BooleanIndicator
from .browser import BrowserInfo
from .callbacks import PeriodicCallback
from .location import Location
from .notifications import NotificationArea
from .server import StoppableThread
T = TypeVar("T")
@contextmanager
def set_curdoc(doc: Document):
token = state._curdoc.set(doc)
try:
yield
finally:
# If _curdoc has been reset it will raise a ValueError
with suppress(ValueError):
state._curdoc.reset(token)
def curdoc_locked() -> Document:
try:
doc = _curdoc()
except RuntimeError:
return None
if isinstance(doc, UnlockedDocumentProxy):
doc = doc._doc
return doc
class _Undefined: pass
Tat = Union[dt.datetime, Callable[[dt.datetime], dt.datetime], TIterator[dt.datetime]]
class _state(param.Parameterized):
"""
Holds global state associated with running apps, allowing running
apps to indicate their state to a user.
"""
busy = param.Boolean(default=False, readonly=True, doc="""
Whether the application is currently busy processing a user
callback.""")
cache = param.Dict(default={}, doc="""
Global location you can use to cache large datasets or expensive computation results
across multiple client sessions for a given server.""")
encryption = param.Parameter(default=None, doc="""
Object with encrypt and decrypt methods to support encryption
of secret variables including OAuth information.""")
session_info = param.Dict(default={'total': 0, 'live': 0,
'sessions': {}}, doc="""
Tracks information and statistics about user sessions.""")
webdriver = param.Parameter(default=None, doc="""
Selenium webdriver used to export bokeh models to pngs.""")
_base_url = param.String(default='/', readonly=True, doc="""
Base URL for all server paths.""")
_busy_counter = param.Integer(default=0, doc="""
Count of active callbacks current being processed.""")
_memoize_cache = param.Dict(default={}, doc="""
A dictionary used by the cache decorator.""")
_rel_path = param.String(default='', readonly=True, doc="""
Relative path from the current app being served to the root URL.
If application is embedded in a different server via autoload.js
this will instead reflect an absolute path.""")
# Holds temporary curdoc overrides per thread
_curdoc = ContextVar('curdoc', default=None)
# Whether to hold comm events
_hold: ClassVar[bool] = False
# Used to ensure that events are not scheduled from the wrong thread
_thread_id_: ClassVar[WeakKeyDictionary[Document, int]] = WeakKeyDictionary()
_thread_pool = None
# Admin application (remove in Panel 1.0 / Bokeh 3.0)
_admin_context = None
# Jupyter communication
_comm_manager: ClassVar[type[_CommManager]] = _CommManager
_jupyter_kernel_context: ClassVar[BokehSessionContext | None] = None
_kernels = {}
_ipykernels: ClassVar[WeakKeyDictionary[Document, Any]] = WeakKeyDictionary()
# Locations
_browser: ClassVar[BrowserInfo | None] = None # Global BrowserInfo, e.g. for notebook context
_browsers: ClassVar[WeakKeyDictionary[Document, BrowserInfo]] = WeakKeyDictionary() # Server browser indexed by document
# Locations
_location: ClassVar[Location | None] = None # Global location, e.g. for notebook context
_locations: ClassVar[WeakKeyDictionary[Document, Location]] = WeakKeyDictionary() # Server locations indexed by document
# Notifications
_notification: ClassVar[NotificationArea | None] = None # Global location, e.g. for notebook context
_notifications: ClassVar[WeakKeyDictionary[Document, NotificationArea]] = WeakKeyDictionary() # Server notifications indexed by document
# Templates
_template: ClassVar[BaseTemplate | None] = None
_templates: ClassVar[WeakKeyDictionary[Document, BaseTemplate]] = WeakKeyDictionary() # Server templates indexed by document
# An index of all currently active views
_views: ClassVar[dict[str, tuple[Viewable, Model, Document, Comm | None]]] = {}
# For templates to keep reference to their main root
_fake_roots: ClassVar[list[str]] = []
# An index of all currently active servers
_servers: ClassVar[dict[str, tuple[Server, Viewable | BaseTemplate, list[Document]]]] = {}
_threads: ClassVar[dict[str, StoppableThread]] = {}
_server_config: ClassVar[WeakKeyDictionary[Any, dict[str, Any]]] = WeakKeyDictionary()
# Jupyter display handles
_handles: ClassVar[dict[str, [DisplayHandle, list[str]]]] = {}
# Stacks for hashing
_stacks = WeakKeyDictionary()
# Dictionary of callbacks to be triggered on app load
_onload: ClassVar[dict[Document, Callable[[], None]]] = WeakKeyDictionary()
_on_session_created: ClassVar[list[Callable[[BokehSessionContext], None]]] = []
_on_session_created_internal: ClassVar[list[Callable[[BokehSessionContext], None]]] = []
_on_session_destroyed: ClassVar[list[Callable[[BokehSessionContext], None]]] = []
_loaded: ClassVar[WeakKeyDictionary[Document, bool]] = WeakKeyDictionary()
# Module that was run during setup
_setup_module = None
# Scheduled callbacks
_scheduled: ClassVar[dict[str, tuple[Iterator[int], Callable[[], None]]]] = {}
_periodic: ClassVar[WeakKeyDictionary[Document, list[PeriodicCallback]]] = WeakKeyDictionary()
# Indicators listening to the busy state
_indicators: ClassVar[list[BooleanIndicator]] = []
# Profilers
_launching = []
_profiles = param.Dict(default=defaultdict(list))
# Endpoints
_rest_endpoints = {}
# Style cache
_stylesheets: ClassVar[WeakKeyDictionary[Document, dict[str, ImportedStyleSheet]]] = WeakKeyDictionary()
# Loaded extensions
_extensions_: ClassVar[WeakKeyDictionary[Document, list[str]]] = WeakKeyDictionary()
# Locks
_cache_locks: ClassVar[dict[str, threading.Lock]] = {'main': threading.Lock()}
# Sessions
_sessions = {}
_session_key_funcs = {}
# Layout editor
_cell_outputs = defaultdict(list)
_cell_layouts = defaultdict(dict)
_session_outputs: ClassVar[WeakKeyDictionary[Document, dict[str, Any]]] = WeakKeyDictionary()
# Override user info
_oauth_user_overrides = {}
_active_users = Counter()
# Paths
_rel_paths: ClassVar[WeakKeyDictionary[Document, str]] = WeakKeyDictionary()
_base_urls: ClassVar[WeakKeyDictionary[Document, str]] = WeakKeyDictionary()
# Watchers
_watch_events: list[asyncio.Event] = []
def __repr__(self) -> str:
server_info = []
for server, panel, _docs in self._servers.values():
server_info.append(
"{}:{:d} - {!r}".format(server.address or "localhost", server.port, panel)
)
if not server_info:
return "state(servers=[])"
return "state(servers=[\n {}\n])".format(",\n ".join(server_info))
@property
def _ioloop(self) -> 'IOLoop':
if state._is_pyodide:
return asyncio.get_running_loop()
else:
from tornado.ioloop import IOLoop
return IOLoop.current()
@property
def _extensions(self):
doc = self.curdoc
if not (doc and doc in self._extensions_):
return
return self._extensions_[doc]
@property
def _current_thread(self) -> str | None:
return threading.get_ident()
@property
def _is_launching(self) -> bool:
curdoc = self.curdoc
if not curdoc or not curdoc.session_context or not curdoc.session_context.server_context:
return False
return not bool(curdoc.session_context.server_context.sessions)
@property
def _is_pyodide(self) -> bool:
return '_pyodide' in sys.modules
@property
def _thread_id(self) -> int | None:
return self._thread_id_.get(self.curdoc) if self.curdoc else None
@_thread_id.setter
def _thread_id(self, thread_id: int) -> None:
if self.curdoc:
self._thread_id_[self.curdoc] = thread_id
def _unblocked(self, doc: Document) -> bool:
"""
Indicates whether Document events can be dispatched or have
to scheduled on the event loop. Events can only be safely
dispatched if:
1. The Document to be modified is the same one that the server
is currently processing.
2. We are on the same thread that the Document was created on.
3. The application has fully loaded and the Websocket is open.
"""
return (
doc is self.curdoc and
self._thread_id in (self._current_thread, None) and
(not (doc and doc.session_context and doc.session_context.session) or self._loaded.get(doc))
)
@param.depends('_busy_counter', watch=True)
def _update_busy_counter(self):
self.busy = self._busy_counter >= 1
@param.depends('busy', watch=True)
def _update_busy(self) -> None:
for indicator in self._indicators:
indicator.value = self.busy
def _init_session(self, event):
if not self.curdoc.session_context:
return
from .server import logger
session_id = self.curdoc.session_context.id
session_info = self.session_info['sessions'].get(session_id, {})
if session_info.get('rendered') is not None:
return
logger.info(LOG_SESSION_RENDERED, id(self.curdoc))
self.session_info['live'] += 1
session_info.update({
'rendered': dt.datetime.now().timestamp()
})
self.param.trigger('session_info')
def _destroy_session(self, session_context):
session_id = session_context.id
sessions = self.session_info['sessions']
if session_id in sessions and sessions[session_id]['ended'] is None:
session = sessions[session_id]
if session['rendered'] is not None:
self.session_info['live'] -= 1
session['ended'] = dt.datetime.now().timestamp()
self.param.trigger('session_info')
doc = session_context._document
# Cleanup periodic callbacks
if doc in self._periodic:
for cb in self._periodic[doc]:
try:
cb._cleanup(session_context)
except Exception:
pass
del self._periodic[doc]
# Cleanup Locations
if doc in self._locations:
loc = state._locations[doc]
loc._server_destroy(session_context)
del state._locations[doc]
# Cleanup Notifications
if doc in self._notifications:
notification = self._notifications[doc]
notification._server_destroy(session_context)
del state._notifications[doc]
# Clean up templates
if doc in self._templates:
del self._templates[doc]
@property
def _current_stack(self):
current_thread = threading.current_thread()
stack = self._stacks.get(current_thread, None)
if stack is None:
from .cache import _Stack
stack = _Stack()
self._stacks[current_thread] = stack
return stack
def _get_callback(self, endpoint: str):
_updating: dict[int, bool] = {}
def link(*events):
event = events[0]
obj = event.cls if event.obj is None else event.obj
parameterizeds = self._rest_endpoints[endpoint][0]
if obj not in parameterizeds:
return
updating = _updating.get(id(obj), [])
values = {event.name: event.new for event in events
if event.name not in updating}
if not values:
return
_updating[id(obj)] = list(values)
for parameterized in parameterizeds:
if id(parameterized) in _updating:
continue
try:
parameterized.param.update(**values)
except Exception:
raise
finally:
if id(obj) in _updating:
not_updated = [p for p in _updating[id(obj)] if p not in values]
if not_updated:
_updating[id(obj)] = not_updated
else:
del _updating[id(obj)]
return link
def _schedule_on_load(self, doc: Document, event) -> None:
if self._thread_pool:
future = self._thread_pool.submit(self._on_load, doc)
future.add_done_callback(partial(self._handle_future_exception, doc=doc))
else:
self._on_load(doc)
def _on_load(self, doc: Optional[Document] = None) -> None:
doc = doc or self.curdoc
if doc not in self._onload:
self._loaded[doc] = True
return
from ..config import config
from .profile import profile_ctx
with set_curdoc(doc):
if (doc and doc in self._launching) or not config.profiler:
while doc in self._onload:
for cb, threaded in self._onload.pop(doc):
self.execute(cb, schedule='thread' if threaded else False)
self._loaded[doc] = True
return
with profile_ctx(config.profiler) as sessions:
while doc in self._onload:
for cb, threaded in self._onload.pop(doc):
self.execute(cb, schedule='thread' if threaded else False)
path = doc.session_context.request.path
self._profiles[(path+':on_load', config.profiler)] += sessions
self.param.trigger('_profiles')
self._loaded[doc] = True
async def _scheduled_cb(self, name: str, threaded: bool = False) -> None:
if name not in self._scheduled:
return
diter, cb = self._scheduled[name]
try:
at = next(diter)
except Exception:
at = None
del self._scheduled[name]
if at is not None:
now = dt.datetime.now().timestamp()
call_time_seconds = (at - now)
self._ioloop.call_later(delay=call_time_seconds, callback=partial(self._scheduled_cb, name))
try:
self.execute(cb, schedule='thread' if threaded else 'auto')
except Exception as e:
self._handle_exception(e)
def _handle_exception_wrapper(self, callback):
@wraps(callback)
def wrapper(*args, **kw):
try:
return callback(*args, **kw)
except Exception as e:
self._handle_exception(e)
return wrapper
def _handle_future_exception(self, future: Future, doc: Document = None) -> None:
exception = future.exception()
if exception is None:
return
with set_curdoc(doc):
self._handle_exception(exception)
def _handle_exception(self, exception) -> None:
from ..config import config
if config.exception_handler:
config.exception_handler(exception)
elif isinstance(exception, BaseException):
raise exception
else:
self.log(f'Exception of unknown type raised: {exception}', level='error')
def _register_session_destroyed(self, session_context: BokehSessionContext):
for cb in self._on_session_destroyed:
session_context._document.on_session_destroyed(cb)
#----------------------------------------------------------------
# Public Methods
#----------------------------------------------------------------
def as_cached(self, key: str, fn: Callable[[], T], ttl: int = None, **kwargs) -> T:
"""
Caches the return value of a function globally across user sessions, memoizing on the given
key and supplied keyword arguments.
Note: Keyword arguments must be hashable.
Pandas Example:
>>> data = pn.state.as_cached('data', pd.read_csv, filepath_or_buffer=DATA_URL)
Function Example:
>>> def load_dataset(name):
>>> # some slow operation that uses name to load a dataset....
>>> return dataset
>>> penguins = pn.state.as_cached('dataset-penguins', load_dataset, name='penguins')
Arguments
---------
key: (str)
The key to cache the return value under.
fn: (callable)
The function or callable whose return value will be cached.
ttl: (int)
The number of seconds to keep an item in the cache, or None
if the cache should not expire. The default is None.
**kwargs: dict
Additional keyword arguments to supply to the function,
which will be memoized over as well.
Returns
-------
Returns the value returned by the cache or the value in
the cache.
"""
key = (key,)+tuple((k, v) for k, v in sorted(kwargs.items()))
new_expiry = time.monotonic() + ttl if ttl else None
with self._cache_locks['main']:
if key in self._cache_locks:
lock = self._cache_locks[key]
else:
self._cache_locks[key] = lock = threading.Lock()
try:
with lock:
if key in self.cache:
ret, expiry = self.cache.get(key)
else:
ret, expiry = _Undefined, None
if ret is _Undefined or (expiry is not None and expiry < time.monotonic()):
ret, _ = self.cache[key] = (fn(**kwargs), new_expiry)
finally:
if not lock.locked() and key in self._cache_locks:
del self._cache_locks[key]
return ret
def add_periodic_callback(
self, callback: Callable[[], None] | Coroutine[Any, Any, None],
period: int=500, count: Optional[int] = None, timeout: int = None,
start: bool=True
) -> PeriodicCallback:
"""
Schedules a periodic callback to be run at an interval set by
the period. Returns a PeriodicCallback object with the option
to stop and start the callback.
Arguments
---------
callback: callable
Callable function to be executed at periodic interval.
period: int
Interval in milliseconds at which callback will be executed.
count: int
Maximum number of times callback will be invoked.
timeout: int
Timeout in seconds when the callback should be stopped.
start: boolean (default=True)
Whether to start callback immediately.
Returns
-------
Return a PeriodicCallback object with start and stop methods.
"""
from .callbacks import PeriodicCallback
cb = PeriodicCallback(
callback=callback, period=period, count=count, timeout=timeout
)
if start:
cb.start()
if self.curdoc:
if self.curdoc not in self._periodic:
self._periodic[self.curdoc] = []
self._periodic[self.curdoc].append(cb)
return cb
def cancel_task(self, name: str, wait: bool=False):
"""
Cancel a task scheduled using the `state.schedule_task` method by name.
Arguments
---------
name: str
The name of the scheduled task.
wait: boolean
Whether to wait until after the next execution.
"""
if name not in self._scheduled:
raise KeyError(f'No task with the name {name!r} has been scheduled.')
if wait:
self._scheduled[name] = (None, self._scheduled[name][1])
else:
del self._scheduled[name]
def clear_caches(self):
"""
Clears caches generated by panel.io.cache function.
"""
for cache in self._memoize_cache.values():
cache.clear()
if hasattr(cache, 'directory'):
cache.cache.close()
try:
shutil.rmtree(cache.directory)
except OSError: # Windows wonkiness
pass
self._memoize_cache.clear()
def _execute_on_thread(self, doc, callback):
with set_curdoc(doc):
if param.parameterized.iscoroutinefunction(callback):
param.parameterized.async_executor(callback)
else:
self.execute(callback, schedule=False)
def execute(
self,
callback: Callable[[], None],
schedule: bool | Literal['auto', 'thread'] = 'auto'
) -> None:
"""
Executes both synchronous and asynchronous callbacks
appropriately depending on the context the application is
running in. When running on the server callbacks are scheduled
on the event loop ensuring the Bokeh Document lock is acquired
and models can be modified directly.
Arguments
---------
callback: Callable[[], None]
Callback to execute
schedule: boolean | Literal['auto', 'thread']
Whether to schedule the callback on the event loop, on a thread
or execute them immediately.
"""
doc = self.curdoc
if schedule == 'thread':
if not state._thread_pool:
raise RuntimeError(
'Cannot execute callback on thread. Ensure you have '
'enabled threading setting `config.nthreads`.'
)
future = state._thread_pool.submit(partial(self._execute_on_thread, doc, callback))
future.add_done_callback(self._handle_future_exception)
elif param.parameterized.iscoroutinefunction(callback):
param.parameterized.async_executor(callback)
elif doc and doc.session_context and (schedule == True or (schedule == 'auto' and not self._unblocked(doc))):
doc.add_next_tick_callback(self._handle_exception_wrapper(callback))
else:
try:
callback()
except Exception as e:
state._handle_exception(e)
def get_profile(self, profile: str):
"""
Returns the requested profiling output.
Arguments
---------
profile: str
The name of the profiling output to return.
Returns
-------
Profiling output wrapped in a pane.
"""
from .profile import get_profiles
return get_profiles({(n, e): ps for (n, e), ps in state._profiles.items()
if n == profile})[0][1]
def kill_all_servers(self) -> None:
"""
Stop all servers and clear them from the current state.
"""
for server_id in self._servers:
if server_id in self._threads:
self._threads[server_id].stop()
else:
try:
self._servers[server_id][0].stop()
except AssertionError: # can't stop a server twice
pass
self._servers.clear()
self._threads.clear()
def log(self, msg: str, level: str = 'info') -> None:
"""
Logs user messages to the Panel logger.
Arguments
---------
msg: str
Log message
level: str
Log level as a string, i.e. 'debug', 'info', 'warning' or 'error'.
"""
args = ()
if self.curdoc:
args = (id(self.curdoc),)
msg = LOG_USER_MSG.format(msg=msg)
getattr(_state_logger, level.lower())(msg, *args)
def onload(self, callback: Callable[[], None | Awaitable[None]] | Coroutine[Any, Any, None], threaded: bool = False):
"""
Callback that is triggered when a session has been served.
Arguments
---------
callback: Callable[[], None] | Coroutine[Any, Any, None]
Callback that is executed when the application is loaded
threaded: bool
Whether the onload callback can be threaded
"""
if self.curdoc is None or self._is_pyodide or self.loaded:
if self._thread_pool:
self.execute(callback, schedule='threaded')
else:
self.execute(callback, schedule=False)
return
elif self.curdoc not in self._onload:
self._onload[self.curdoc] = []
self._onload[self.curdoc].append((callback, threaded))
def on_session_created(self, callback: Callable[[BokehSessionContext], None]) -> None:
"""
Callback that is triggered when a session is created.
"""
if self.curdoc and self.curdoc.session_context:
raise RuntimeError(
"Cannot register session creation callback from within a session. "
"If running a Panel application from the CLI set up the callback "
"in a --setup script, if starting a server dynamically set it up "
"before starting the server."
)
self._on_session_created.append(callback)
def on_session_destroyed(self, callback: Callable[[BokehSessionContext], None]) -> None:
"""
Callback that is triggered when a session is destroyed.
"""
doc = self.curdoc
if doc:
doc.on_session_destroyed(callback)
else:
if self._register_session_destroyed not in self._on_session_created:
self._on_session_created.append(self._register_session_destroyed)
self._on_session_destroyed.append(callback)
def publish(
self, endpoint: str, parameterized: param.Parameterized,
parameters: Optional[list[str]] = None
) -> None:
"""
Publish parameters on a Parameterized object as a REST API.
Arguments
---------
endpoint: str
The endpoint at which to serve the REST API.
parameterized: param.Parameterized
The Parameterized object to publish parameters from.
parameters: list(str) or None
A subset of parameters on the Parameterized to publish.
"""
if parameters is None:
parameters = list(parameterized.param)
if endpoint.startswith('/'):
endpoint = endpoint[1:]
if endpoint in self._rest_endpoints:
parameterizeds, old_parameters, cb = self._rest_endpoints[endpoint]
if set(parameters) != set(old_parameters):
raise ValueError("Param REST API output parameters must match across sessions.")
values = {k: v for k, v in parameterizeds[0].param.values().items() if k in parameters}
parameterized.param.update(**values)
parameterizeds.append(parameterized)
else:
cb = self._get_callback(endpoint)
self._rest_endpoints[endpoint] = ([parameterized], parameters, cb)
parameterized.param.watch(cb, parameters)
def reset(self):
"""
Resets the state object killing running servers and clearing
any other state held by the server.
"""
self.kill_all_servers()
self._curdoc = ContextVar('curdoc', default=None)
self._indicators.clear()
self._location = None
self._locations.clear()
self._templates.clear()
self._views.clear()
self._loaded.clear()
self.cache.clear()
self._scheduled.clear()
if self._thread_pool is not None:
self._thread_pool.shutdown(wait=False)
self._thread_pool = None
self._sessions.clear()
self._session_key_funcs.clear()
self._on_session_created.clear()
self._on_session_destroyed.clear()
self._stylesheets.clear()
self._scheduled.clear()
self._periodic.clear()
def schedule_task(
self, name: str, callback: Callable[[], None], at: Tat =None,
period: str | dt.timedelta = None, cron: Optional[str] = None,
threaded : bool = False
) -> None:
"""
Schedules a task at a specific time or on a schedule.
By default the starting time is immediate but may be
overridden with the `at` keyword argument. The scheduling may
be declared using the `period` argument or a cron expression
(which requires the `croniter` library). Note that the `at`
time should be in local time but if a callable is provided it
must return a UTC time.
Note that the scheduled callback must not be defined within a
script served using `panel serve` because the script and all
its contents are cleaned up when the user session is
destroyed. Therefore the callback must be imported from a
separate module or should be scheduled from a setup script
(provided to `panel serve` using the `--setup` argument). Note
also that scheduling is idempotent, i.e. if a callback has
already been scheduled under the same name subsequent calls
will have no effect. This is ensured that even if you schedule
a task from within your application code, the task is only
scheduled once.
Arguments
---------
name: str
Name of the scheduled task
callback: callable
Callback to schedule
at: datetime.datetime, Iterator or callable
Declares a time to schedule the task at. May be given as a
datetime or an Iterator of datetimes in the local timezone
declaring when to execute the task. Alternatively may also
declare a callable which is given the current UTC time and
must return a datetime also in UTC.
period: str or datetime.timedelta
The period between executions, may be expressed as a
timedelta or a string:
- Week: '1w'
- Day: '1d'
- Hour: '1h'
- Minute: '1m'
- Second: '1s'
cron: str
A cron expression (requires croniter to parse)
threaded: bool
Whether the callback should be run on a thread (requires
config.nthreads to be set).
"""
name = f"{os.getpid()}_{name}"
if name in self._scheduled:
if callback is not self._scheduled[name][1]:
self.param.warning(
"A separate task was already scheduled under the "
f"name {name!r}. The new task will be ignored. If "
"you want to replace the existing task cancel it "
f"with `state.cancel_task({name!r})` before adding "
"adding a new task under the same name."
)
return
if getattr(callback, '__module__', '').startswith('bokeh_app_'):
raise RuntimeError(
"Cannot schedule a task from within the context of an "
"application. Either import the task callback from a "
"separate module or schedule the task from a setup "
"script that you provide to `panel serve` using the "
"--setup commandline argument."
)
if cron is None:
if isinstance(period, str):
period = parse_timedelta(period)
def dgen():
if isinstance(at, Iterator):
while True:
new = next(at)
yield new.timestamp()
elif callable(at):
while True:
new = at(dt.datetime.now(dt.timezone.utc).replace(tzinfo=None))
if new is None:
raise StopIteration
yield new.replace(tzinfo=dt.timezone.utc).astimezone().timestamp()
elif period is None:
yield at.timestamp()
raise StopIteration
new_time = at or dt.datetime.now()
while True:
yield new_time.timestamp()
new_time += period
diter = dgen()
else:
from croniter import croniter
base = dt.datetime.now() if at is None else at
diter = croniter(cron, base)
now = dt.datetime.now().timestamp()
try:
call_time_seconds = (next(diter) - now)
except StopIteration:
return
self._scheduled[name] = (diter, callback)
self._ioloop.call_later(
delay=call_time_seconds, callback=partial(self._scheduled_cb, name, threaded)
)
def sync_busy(self, indicator: BooleanIndicator) -> None:
"""
Syncs the busy state with an indicator with a boolean value
parameter.
Arguments
---------
indicator: An BooleanIndicator to sync with the busy property
"""
if not isinstance(indicator.param.value, param.Boolean):
raise ValueError("Busy indicator must have a value parameter"
"of Boolean type.")
if indicator not in self._indicators:
self._indicators.append(indicator)
#----------------------------------------------------------------
# Public Properties
#----------------------------------------------------------------
def _decode_cookie(self, cookie_name, cookie=None):
from tornado.web import decode_signed_value
from ..config import config
cookie = self.cookies.get(cookie_name)
if cookie is None:
return None
cookie = decode_signed_value(config.cookie_secret, cookie_name, cookie)
return self._decrypt_cookie(cookie)
def _decrypt_cookie(self, cookie):
if self.encryption is None:
return cookie.decode('utf-8')
return self.encryption.decrypt(cookie).decode('utf-8')
@property
def access_token(self) -> str | None:
"""
Returns the OAuth access_token if enabled.
"""
if self.user in self._oauth_user_overrides and 'access_token' in self._oauth_user_overrides[self.user]:
return self._oauth_user_overrides[self.user]['access_token']
access_token = self._decode_cookie('access_token')
if not access_token:
return
try:
decoded_token = decode_token(access_token)
except Exception:
return access_token
if decoded_token['exp'] <= dt.datetime.now(dt.timezone.utc).timestamp():
return None
return access_token
@property
def app_url(self) -> str | None:
"""
Returns the URL of the app that is currently being executed.
"""
if not self.curdoc:
return
app_url = self.curdoc.session_context.server_context.application_context.url
app_url = app_url[1:] if app_url.startswith('/') else app_url
return urljoin(self.base_url, app_url)
@property
def browser_info(self) -> BrowserInfo | None:
from ..config import config
from .browser import BrowserInfo
if config.browser_info and self.curdoc and self.curdoc.session_context and self.curdoc not in self._browsers:
browser = self._browsers[self.curdoc] = BrowserInfo()
elif self.curdoc is None:
if self._browser is None and config.browser_info:
self._browser = BrowserInfo()
browser = self._browser
else:
browser = self._browsers.get(self.curdoc) if self.curdoc else None
return browser
@property
def curdoc(self) -> Document | None:
"""
Returns the Document that is currently being executed.
"""
curdoc = self._curdoc.get()
if curdoc:
return curdoc
try:
doc = curdoc_locked()
pyodide_session = self._is_pyodide and 'pyodide_kernel' not in sys.modules
if doc and (doc.session_context or pyodide_session):
return doc
except Exception:
return None
@curdoc.setter
def curdoc(self, doc: Document) -> None:
"""
Overrides the current Document.
"""
self._curdoc.set(doc)
@property
def cookies(self) -> dict[str, str]:
"""
Returns the cookies associated with the request that started the session.
"""
return self.curdoc.session_context.request.cookies if self.curdoc and self.curdoc.session_context else {}
@property
def headers(self) -> dict[str, str | list[str]]:
"""
Returns the header associated with the request that started the session.
"""
return self.curdoc.session_context.request.headers if self.curdoc and self.curdoc.session_context else {}
@property
def base_url(self) -> str:
base_url = self._base_url
if self.curdoc:
return self._base_urls.get(self.curdoc, base_url)
return base_url
@base_url.setter
def base_url(self, value: str):
if self.curdoc:
self._base_urls[self.curdoc] = value
else:
self._base_url = value
@property
def rel_path(self) -> str | None:
rel_path = self._rel_path
if self.curdoc:
return self._rel_paths.get(self.curdoc, rel_path)
return rel_path
@rel_path.setter
def rel_path(self, value: str | None):
if self.curdoc:
self._rel_paths[self.curdoc] = value
else:
self._rel_path = value
@property
def loaded(self) -> bool:
"""
Whether the application has been fully loaded.
"""
curdoc = self.curdoc
if curdoc:
if curdoc in self._loaded:
return self._loaded[curdoc]
elif curdoc.session_context:
return False
return True
@property
def location(self) -> Location | None:
if self.curdoc and self.curdoc not in self._locations:
from .location import Location
if self.curdoc.session_context:
loc = Location.from_request(self.curdoc.session_context.request)
else:
loc = Location()
self._locations[self.curdoc] = loc
elif self.curdoc is None:
loc = self._location
else:
loc = self._locations.get(self.curdoc) if self.curdoc else None
return loc
@property
def log_terminal(self):
from .admin import log_terminal
return log_terminal
@property
def notifications(self) -> NotificationArea | None:
if self.curdoc is None:
return self._notification
is_session = (self.curdoc.session_context is not None or self._is_pyodide)
if self.curdoc in self._notifications:
return self._notifications[self.curdoc]
from panel.config import config
if not (config.notifications and is_session):
return None if is_session else self._notification
from panel.io.notifications import NotificationArea
js_events = {}
if config.ready_notification:
js_events['document_ready'] = {'type': 'success', 'message': config.ready_notification, 'duration': 3000}
if config.disconnect_notification:
js_events['connection_lost'] = {'type': 'error', 'message': config.disconnect_notification}
self._notifications[self.curdoc] = notifications = NotificationArea(js_events=js_events)
return notifications
@property
def refresh_token(self) -> str | None:
"""
Returns the OAuth refresh_token if enabled and available.
"""
if self.user in self._oauth_user_overrides and 'refresh_token' in self._oauth_user_overrides:
return self._oauth_user_overrides[self.user]['refresh_token']
refresh_token = self._decode_cookie('refresh_token')
if not refresh_token:
return
try:
decoded_token = decode_token(refresh_token)
except ValueError:
return refresh_token
if decoded_token['exp'] <= dt.datetime.now(dt.timezone.utc).timestamp():
return None
return refresh_token
@property
def served(self):
"""
Whether we are currently inside a script or notebook that is
being served using `panel serve`.
"""
try:
return inspect.stack()[1].frame.f_globals['__name__'].startswith('bokeh_app_')
except Exception:
return False
@property
def session_args(self) -> dict[str, list[bytes]]:
"""
Returns the request arguments associated with the request that started the session.
"""
return self.curdoc.session_context.request.arguments if self.curdoc and self.curdoc.session_context else {}
@property
def template(self) -> BaseTemplate | None:
from ..config import config
if self.curdoc in self._templates:
return self._templates[self.curdoc]
elif self.curdoc is None and self._template:
return self._template
template = config.template(theme=config.theme)
if not config.design:
config.design = template.design
if self.curdoc is None:
self._template = template
else:
self._templates[self.curdoc] = template
return template
@property
def user(self) -> str | None:
"""
Returns the OAuth user if enabled.
"""
from tornado.web import decode_signed_value
from ..config import config
is_guest = self.cookies.get('is_guest')
if is_guest:
return "guest"
user = self.cookies.get('user')
if user is None or config.cookie_secret is None:
return None
return decode_signed_value(config.cookie_secret, 'user', user).decode('utf-8')
@property
def user_info(self) -> dict[str, Any] | None:
"""
Returns the OAuth user information if enabled.
"""
is_guest = self.cookies.get('is_guest')
if is_guest:
return {"user": "guest", "username": "guest"}
id_token = self._decode_cookie('id_token')
if id_token is None:
return None
return decode_token(id_token)
state = _state()