'''
'''
from __future__ import absolute_import, print_function
import logging
log = logging.getLogger(__name__)
from bokeh.resources import ( DEFAULT_SERVER_WEBSOCKET_URL,
server_url_for_websocket_url,
_SessionCoordinates )
from bokeh.document import Document
from bokeh.util.session_id import generate_session_id
DEFAULT_SESSION_ID = "default"
[docs]def push_session(document, session_id=None, url='default', app_path='/', io_loop=None):
""" Create a session by pushing the given document to the server,
overwriting any existing server-side document.
``session.document`` in the returned session will be your
supplied document. While the connection to the server is
open, changes made on the server side will be applied to
this document, and changes made on the client side will be
synced to the server.
In a production scenario, the ``session_id`` should be
unique for each browser tab, which keeps users from
stomping on each other. It's neither scalable nor secure to
use predictable session IDs or to share session IDs across
users.
For a notebook running on a single machine, ``session_id``
could be something human-readable such as ``"default"`` for
convenience.
If you allow ``push_session()`` to generate a unique
``session_id``, you can obtain the generated ID with the
``id`` property on the returned ``ClientSession``.
Args:
document : bokeh.document.Document
The document to be pushed and set as session.document
session_id : string, optional
The name of the session, None to autogenerate a random one (default: None)
url : str, optional
The base server URL to connect to (default: 'default')
app_path : str, optional
Relative path to the app on the server (defualt: '/')
io_loop : tornado.ioloop.IOLoop, optional
The IOLoop to use for the websocket
Returns:
ClientSession
A new ClientSession connected to the server
"""
coords = _SessionCoordinates(dict(session_id=session_id, url=url, app_path=app_path))
session = ClientSession(session_id=coords.session_id, websocket_url=coords.websocket_url, io_loop=io_loop)
session.push(document)
return session
[docs]def pull_session(session_id=None, url='default', app_path='/', io_loop=None):
""" Create a session by loading the current server-side document.
``session.document`` will be a fresh document loaded from
the server. While the connection to the server is open,
changes made on the server side will be applied to this
document, and changes made on the client side will be
synced to the server.
If you don't plan to modify ``session.document`` you probably
don't need to use this function; instead you can directly
``show_session()`` or ``autoload_server()`` without downloading
the session's document into your process first. It's much
more efficient to avoid downloading the session if you don't need
to.
In a production scenario, the ``session_id`` should be
unique for each browser tab, which keeps users from
stomping on each other. It's neither scalable nor secure to
use predictable session IDs or to share session IDs across
users.
For a notebook running on a single machine, ``session_id``
could be something human-readable such as ``"default"`` for
convenience.
If you allow ``pull_session()`` to generate a unique
``session_id``, you can obtain the generated ID with the
``id`` property on the returned ``ClientSession``.
Args:
session_id (string, optional) :
The name of the session, None to autogenerate a random one (default: None)
url (str, optional) :
The base server URL to connect to (default: 'default')
app_path (str, optional) :
Relative path to the app on the server (default: '/')
io_loop (``tornado.ioloop.IOLoop``, optional) :
The IOLoop to use for the websocket
Returns:
ClientSession :
A new ClientSession connected to the server
"""
coords = _SessionCoordinates(dict(session_id=session_id, url=url, app_path=app_path))
session = ClientSession(session_id=session_id, websocket_url=coords.websocket_url, io_loop=io_loop)
session.pull()
return session
def _encode_query_param(s):
try:
import urllib
return urllib.quote_plus(s)
except:
# python 3
import urllib.parse as parse
return parse.quote_plus(s)
_new_param = {'tab': 2, 'window': 1}
[docs]def show_session(session_id=None, url='default', app_path='/',
session=None, browser=None, new="tab", controller=None):
""" Open a browser displaying a session document.
If you have a session from ``pull_session()`` or
``push_session`` you can ``show_session(session=mysession)``.
If you don't need to open a connection to the server yourself,
you can show a new session in a browser by providing just the
``url`` and ``app_path``.
Args:
session_id (string, optional) :
The name of the session, None to autogenerate a random one (default: None)
url (str, optional) :
The base server URL to connect to (default: 'default')
app_path (str, optional) :
Relative path to the app on the server (defualt: '/')
session (ClientSession, optional) : session to get session ID and server URL from
If you specify this, you don't need to specify session_id and url
browser (str, optional) : browser to show with (default: None)
For systems that support it, the **browser** argument allows
specifying which browser to display in, e.g. "safari", "firefox",
"opera", "windows-default" (see the ``webbrowser`` module
documentation in the standard lib for more details).
new (str, optional) : new file output mode (default: "tab")
For file-based output, opens or raises the browser window
showing the current output file. If **new** is 'tab', then
opens a new tab. If **new** is 'window', then opens a new window.
"""
if session is not None:
server_url = server_url_for_websocket_url(session._connection.url)
session_id = session.id
else:
coords = _SessionCoordinates(dict(session_id=session_id, url=url, app_path=app_path))
server_url = coords.server_url
session_id = coords.session_id
if controller is None:
from bokeh.util.browser import get_browser_controller
controller = get_browser_controller(browser=browser)
controller.open(server_url + "?bokeh-session-id=" + _encode_query_param(session_id),
new=_new_param[new])
[docs]class ClientSession(object):
""" Represents a websocket connection to a server-side session.
Each server session stores a Document, which is kept in sync
with the document in this ClientSession instance.
Always call either pull() or push() immediately after
creating the session, if you construct a session by hand.
"""
def __init__(self, session_id=None, websocket_url=DEFAULT_SERVER_WEBSOCKET_URL, io_loop=None):
'''
A connection which attaches to a particular named session on the server.
Always call either pull() or push() immediately after creating the session
(until these are called session.document will be None).
The bokeh.client.push_session() and bokeh.client.pull_session() functions
will construct a ClientSession and push or pull in one step, so they are
a good way to obtain a ClientSession.
Args:
session_id (str) :
The name of the session or None to generate one
websocket_url (str) :
Websocket URL to connect to
io_loop (``tornado.ioloop.IOLoop``, optional) :
The IOLoop to use for the websocket
'''
self._document = None
self._id = self._ensure_session_id(session_id)
from ._connection import ClientConnection
self._connection = ClientConnection(session=self, io_loop=io_loop, websocket_url=websocket_url)
from bokeh.util.tornado import _DocumentCallbackGroup
self._callbacks = _DocumentCallbackGroup(self._connection.io_loop)
def _attach_document(self, document):
self._document = document
self._document.on_change_dispatch_to(self)
self._callbacks.add_session_callbacks(self._document.session_callbacks)
[docs] def pull(self):
""" Pull the server's state and set it as session.document.
If this is called more than once, session.document will
be the same object instance but its contents will be overwritten.
Automatically calls :func:`connect` before pulling.
"""
self.connect()
if not self._connection.connected:
raise IOError("Cannot pull session document because we failed to connect to the server (to start the server, try the 'bokeh serve' command)")
if self._document is None:
doc = Document()
else:
doc = self._document
self._connection.pull_doc(doc)
if self._document is None:
self._attach_document(doc)
[docs] def push(self, document=None):
""" Push the given document to the server and record it as session.document.
If this is called more than once, the Document has to be the same (or None
to mean "session.document").
.. note::
Automatically calls :func:`~connect` before pushing.
Args:
document (:class:`~bokeh.document.Document`, optional) :
The document which will be kept in sync with the server document.
None to use session.document or create a new document.
"""
if self._document is None:
if document is None:
doc = Document()
else:
doc = document
else:
if document is None:
doc = self._document
else:
raise ValueError("Cannot push() a different document from existing session.document")
self.connect()
if not self._connection.connected:
raise IOError("Cannot push session document because we failed to connect to the server (to start the server, try the 'bokeh serve' command)")
self._connection.push_doc(doc)
if self._document is None:
self._attach_document(doc)
[docs] def show(self, obj=None, browser=None, new="tab"):
""" Open a browser displaying this session.
Args:
obj (LayoutDOM object, optional) : a Layout (Row/Column),
Plot or Widget object to display. The object will be added
to the session's document.
browser (str, optional) : browser to show with (default: None)
For systems that support it, the **browser** argument allows
specifying which browser to display in, e.g. "safari", "firefox",
"opera", "windows-default" (see the ``webbrowser`` module
documentation in the standard lib for more details).
new (str, optional) : new file output mode (default: "tab")
For file-based output, opens or raises the browser window
showing the current output file. If **new** is 'tab', then
opens a new tab. If **new** is 'window', then opens a new window.
"""
if obj and obj not in self.document.roots:
self.document.add_root(obj)
show_session(session=self, browser=browser, new=new)
@classmethod
def _ensure_session_id(cls, session_id):
if session_id is None:
session_id = generate_session_id()
return session_id
@property
def document(self):
""" :class:`~bokeh.document.Document` which will be kept in sync with the server document
This is initialized when :func:`pull` or :func:`push` succeeds. It will be None until then.
"""
return self._document
@property
def id(self):
return self._id
@property
def connected(self):
return self._connection.connected
def connect(self):
self._connection.connect()
def close(self, why="closed"):
self._connection.close(why)
def loop_until_closed(self):
self._connection.loop_until_closed()
[docs] def request_server_info(self):
''' Ask for information about the server.
Returns:
A dictionary of server attributes.
'''
return self._connection.request_server_info()
[docs] def force_roundtrip(self):
''' Used in unit testing to force a request/reply pair in order to avoid races
'''
self._connection.force_roundtrip()
def _notify_disconnected(self):
''' Called by the ClientConnection we are using to notify us of disconnect.
'''
if self._document is not None:
self._document.remove_on_change(self)
self._callbacks.remove_all_callbacks()
def _document_patched(self, event):
if event.setter is self:
log.debug("Not sending notification back to server for a change it requested")
return
# TODO (havocp): our "change sync" protocol is flawed
# because if both sides change the same attribute at the
# same time, they will each end up with the state of the
# other and their final states will differ.
self._connection._send_patch_document(self._id, event)
def _handle_patch(self, message):
message.apply_to_document(self.document, self)
def _session_callback_added(self, event):
self._callbacks.add_session_callback(event.callback)
def _session_callback_removed(self, event):
self._callbacks.remove_session_callback(event.callback)
