Source code for bokeh.server.callbacks

''' Provide classes to represent callback code that can be associate with
Bokeh Documents and Sessions.

'''
from __future__ import absolute_import

from ..util.serialization import make_id
from ..util.tornado import _CallbackGroup

[docs]class SessionCallback(object): ''' A base class for callback objects associated with Bokeh Documents and Sessions. '''
[docs] def __init__(self, document, callback, id=None): ''' Args: document (Document) : callback (callable) : id (str, optional) : ''' self._id = make_id() if id is None else id self._document = document self._callback = callback
@property def id(self): ''' A unique ID for this callback ''' return self._id @property def callback(self): ''' The callable that this callback wraps. ''' return self._callback
[docs] def remove(self): ''' Remove this session callback its document. ''' self.document._remove_session_callback(self)
def _copy_with_changed_callback(self, new_callback): ''' Internal API used to wrap the callback with decorators. ''' raise NotImplementedError("_copy_with_changed_callback")
[docs]class NextTickCallback(SessionCallback): ''' Represent a callback to execute on the next IOLoop "tick". '''
[docs] def __init__(self, document, callback, id=None): ''' Args: document (Document) : callback (callable) : id (str, optional) : ''' super(NextTickCallback, self).__init__(document, callback, id)
def _copy_with_changed_callback(self, new_callback): ''' Internal API used to wrap the callback with decorators. ''' return NextTickCallback(self._document, new_callback, self._id)
[docs]class PeriodicCallback(SessionCallback): ''' Represent a callback to execute periodically on the IOLoop at a specified periodic time interval. '''
[docs] def __init__(self, document, callback, period, id=None): ''' Args: document (Document) : callback (callable) : period (int) : id (str, optional) : ''' super(PeriodicCallback, self).__init__(document, callback, id) self._period = period
@property def period(self): ''' The period time (in milliseconds) that this callback should repeat execution at. ''' return self._period def _copy_with_changed_callback(self, new_callback): ''' Internal API used to wrap the callback with decorators. ''' return PeriodicCallback(self._document, new_callback, self._period, self._id)
[docs]class TimeoutCallback(SessionCallback): ''' Represent a callback to execute once on the IOLoop after a specifeed time interval passes. '''
[docs] def __init__(self, document, callback, timeout, id=None): ''' Args: document (Document) : callback (callable) : timeout (int) : id (str, optional) : ''' super(TimeoutCallback, self).__init__(document, callback, id) self._timeout = timeout
@property def timeout(self): ''' The timeout (in milliseconds) that the callback should run after. ''' return self._timeout def _copy_with_changed_callback(self, new_callback): ''' Internal API used to wrap the callback with decorators. ''' return TimeoutCallback(self._document, new_callback, self._timeout, self._id)
class _DocumentCallbackGroup(object): ''' ''' def __init__(self, io_loop=None): ''' ''' self._group = _CallbackGroup(io_loop) # from callback ids to removers self._removers = dict() def remove_all_callbacks(self): ''' ''' for r in list(self._removers.values()): r() def add_session_callbacks(self, callbacks): ''' ''' for cb in callbacks: self.add_session_callback(cb) def add_session_callback(self, callback): ''' ''' def cleanup(func): if callback.id in self._removers: del self._removers[callback.id] if isinstance(callback, PeriodicCallback): remover = self._group.add_periodic_callback(callback.callback, callback.period, cleanup) elif isinstance(callback, TimeoutCallback): remover = self._group.add_timeout_callback(callback.callback, callback.timeout, cleanup) elif isinstance(callback, NextTickCallback): remover = self._group.add_next_tick_callback(callback.callback, cleanup) else: raise ValueError("Expected callback of type PeriodicCallback, TimeoutCallback, NextTickCallback, got: %s" % callback.callback) self._removers[callback.id] = remover def remove_session_callback(self, callback): ''' ''' # we may be called multiple times because of multiple # views on a document - the document has to notify that # the callback was removed even if only one view invoked # it. So we need to silently no-op if we're already # removed. if callback.id in self._removers: self._removers[callback.id]()