''' Provide events that represent various changes to Bokeh Documents.
These events are used internally to signal changes to Documents. For
information about user-facing (e.g. UI or tool) events, see the reference
for :ref:`bokeh.events`.
'''
from __future__ import absolute_import
[docs]class DocumentChangedEvent(object):
''' Base class for all internal events representing a change to a
Bokeh Document.
'''
[docs] def __init__(self, document, setter=None):
'''
Args:
document (Document) :
A Bokeh document that is to be updated.
setter (ClientSession or ServerSession or None, optional) :
This is used to prevent "boomerang" updates to Bokeh apps.
(default: None)
In the context of a Bokeh server application, incoming updates
to properties will be annotated with the session that is
doing the updating. This value is propagated through any
subsequent change notifications that the update triggers.
The session can compare the event setter to itself, and
suppress any updates that originate from itself.
'''
self.document = document
self.setter = setter
[docs] def dispatch(self, receiver):
''' Dispatch handling of this event to a receiver.
This method will invoke ``receiver._document_changed`` if it exists.
'''
if hasattr(receiver, '_document_changed'):
receiver._document_changed(self)
[docs]class DocumentPatchedEvent(DocumentChangedEvent):
''' A Base class for events that represent updating Bokeh Models and
their properties.
'''
[docs] def dispatch(self, receiver):
''' Dispatch handling of this event to a receiver.
This method will invoke ``receiver._document_patched`` if it exists.
'''
super(DocumentPatchedEvent, self).dispatch(receiver)
if hasattr(receiver, '_document_patched'):
receiver._document_patched(self)
[docs] def generate(self, references, buffers):
''' Create a JSON representation of this event suitable for sending
to clients.
*Sub-classes must implement this method.*
Args:
references (dict[str, Model]) :
If the event requires references to certain models in order to
function, they may be collected here.
**This is an "out" parameter**. The values it contains will be
modified in-place.
buffers (set) :
If the event needs to supply any additional Bokeh protocol
buffers, they may be added to this set.
**This is an "out" parameter**. The values it contains will be
modified in-place.
'''
raise NotImplementedError()
[docs]class ModelChangedEvent(DocumentPatchedEvent):
''' A concrete event representing updating an attribute and value of a
specific Bokeh Model.
This is the "standard" way of updating most Bokeh model attributes. For
special casing situations that can optimized (e.g. streaming, etc.), a
``hint`` may be supplied that overrides normal mechanisms.
'''
[docs] def __init__(self, document, model, attr, old, new, serializable_new, hint=None, setter=None):
'''
Args:
document (Document) :
A Bokeh document that is to be updated.
model (Model) :
A Model to update
attr (str) :
The name of the attribute to update on the model.
old (object) :
The old value of the attribute
new (object) :
The new value of the attribute
serializable_new (object) :
A serialized (JSON) version of the new value. It may be
``None`` if a hint is supplied.
hint (DocumentPatchedEvent, optional) :
When appropriate, a secondary event may be supplied that
modifies the normal update process. For example, in order
to stream or patch data more efficiently than the standard
update mechanism.
setter (ClientSession or ServerSession or None, optional) :
This is used to prevent "boomerang" updates to Bokeh apps.
(default: None)
See :class:`~bokeh.document.events.DocumentChangedEvent`
for more details.
'''
if setter is None and isinstance(hint, (ColumnsStreamedEvent, ColumnsPatchedEvent)):
setter = hint.setter
super(ModelChangedEvent, self).__init__(document, setter)
self.model = model
self.attr = attr
self.old = old
self.new = new
self.serializable_new = serializable_new
self.hint = hint
[docs] def dispatch(self, receiver):
''' Dispatch handling of this event to a receiver.
This method will invoke ``receiver._document_model_dhanged`` if it
exists.
'''
super(ModelChangedEvent, self).dispatch(receiver)
if hasattr(receiver, '_document_model_changed'):
receiver._document_model_changed(self)
[docs] def generate(self, references, buffers):
''' Create a JSON representation of this event suitable for sending
to clients.
Args:
references (dict[str, Model]) :
If the event requires references to certain models in order to
function, they may be collected here.
**This is an "out" parameter**. The values it contains will be
modified in-place.
buffers (set) :
If the event needs to supply any additional Bokeh protocol
buffers, they may be added to this set.
**This is an "out" parameter**. The values it contains will be
modified in-place.
'''
from ..model import collect_models
if self.hint is not None:
return self.hint.generate(references, buffers)
value = self.serializable_new
# the new value is an object that may have
# not-yet-in-the-remote-doc references, and may also
# itself not be in the remote doc yet. the remote may
# already have some of the references, but
# unfortunately we don't have an easy way to know
# unless we were to check BEFORE the attr gets changed
# (we need the old _all_models before setting the
# property). So we have to send all the references the
# remote could need, even though it could be inefficient.
# If it turns out we need to fix this we could probably
# do it by adding some complexity.
value_refs = set(collect_models(value))
# we know we don't want a whole new copy of the obj we're patching
# unless it's also the new value
if self.model != value:
value_refs.discard(self.model)
references.update(value_refs)
return { 'kind' : 'ModelChanged',
'model' : self.model.ref,
'attr' : self.attr,
'new' : value }
[docs]class ColumnDataChangedEvent(DocumentPatchedEvent):
''' A concrete event representing efficiently replacing *all*
existing data for a :class:`~bokeh.models.sources.ColumnDataSource`
'''
[docs] def __init__(self, document, column_source, cols=None, setter=None):
'''
Args:
document (Document) :
A Bokeh document that is to be updated.
column_source (ColumnDataSource) :
cols (list[str]) :
optional explicit list of column names to update. If None, all
columns will be updated (default: None)
setter (ClientSession or ServerSession or None, optional) :
This is used to prevent "boomerang" updates to Bokeh apps.
(default: None)
See :class:`~bokeh.document.events.DocumentChangedEvent`
for more details.
'''
super(ColumnDataChangedEvent, self).__init__(document, setter)
self.column_source = column_source
self.cols = cols
[docs] def dispatch(self, receiver):
''' Dispatch handling of this event to a receiver.
This method will invoke ``receiver._column_data_changed`` if it exists.
'''
super(ColumnDataChangedEvent, self).dispatch(receiver)
if hasattr(receiver, '_column_data_changed)'):
receiver._column_data_changed(self)
[docs] def generate(self, references, buffers):
''' Create a JSON representation of this event suitable for sending
to clients.
.. code-block:: python
{
'kind' : 'ColumnDataChanged'
'column_source' : <reference to a CDS>
'new' : <new data to steam to column_source>
'cols' : <specific columns to update>
}
Args:
references (dict[str, Model]) :
If the event requires references to certain models in order to
function, they may be collected here.
**This is an "out" parameter**. The values it contains will be
modified in-place.
buffers (set) :
If the event needs to supply any additional Bokeh protocol
buffers, they may be added to this set.
**This is an "out" parameter**. The values it contains will be
modified in-place.
'''
from ..util.serialization import transform_column_source_data
data_dict = transform_column_source_data(self.column_source.data, buffers=buffers, cols=self.cols)
return { 'kind' : 'ColumnDataChanged',
'column_source' : self.column_source.ref,
'new' : data_dict,
'cols' : self.cols}
[docs]class ColumnsStreamedEvent(DocumentPatchedEvent):
''' A concrete event representing efficiently streaming new data
to a :class:`~bokeh.models.sources.ColumnDataSource`
'''
[docs] def __init__(self, document, column_source, data, rollover, setter=None):
'''
Args:
document (Document) :
A Bokeh document that is to be updated.
column_source (ColumnDataSource) :
The data source to stream new data to.
data (dict) :
rollover (int) :
A rollover limit. If the data source columns exceed this
limit, earlier values will be discarded to maintain the
column length under the limit.
setter (ClientSession or ServerSession or None, optional) :
This is used to prevent "boomerang" updates to Bokeh apps.
(default: None)
See :class:`~bokeh.document.events.DocumentChangedEvent`
for more details.
'''
super(ColumnsStreamedEvent, self).__init__(document, setter)
self.column_source = column_source
self.data = data
self.rollover = rollover
[docs] def dispatch(self, receiver):
''' Dispatch handling of this event to a receiver.
This method will invoke ``receiver._columns_streamed`` if it exists.
'''
super(ColumnsStreamedEvent, self).dispatch(receiver)
if hasattr(receiver, '_columns_streamed'):
receiver._columns_streamed(self)
[docs] def generate(self, references, buffers):
''' Create a JSON representation of this event suitable for sending
to clients.
.. code-block:: python
{
'kind' : 'ColumnsStreamed'
'column_source' : <reference to a CDS>
'data' : <new data to steam to column_source>
'rollover' : <rollover limit>
}
Args:
references (dict[str, Model]) :
If the event requires references to certain models in order to
function, they may be collected here.
**This is an "out" parameter**. The values it contains will be
modified in-place.
buffers (set) :
If the event needs to supply any additional Bokeh protocol
buffers, they may be added to this set.
**This is an "out" parameter**. The values it contains will be
modified in-place.
'''
return { 'kind' : 'ColumnsStreamed',
'column_source' : self.column_source.ref,
'data' : self.data,
'rollover' : self.rollover }
[docs]class ColumnsPatchedEvent(DocumentPatchedEvent):
''' A concrete event representing efficiently applying data patches
to a :class:`~bokeh.models.sources.ColumnDataSource`
'''
[docs] def __init__(self, document, column_source, patches, setter=None):
'''
Args:
document (Document) :
A Bokeh document that is to be updated.
column_source (ColumnDataSource) :
The data source to apply patches to.
patches (list) :
setter (ClientSession or ServerSession or None, optional) :
This is used to prevent "boomerang" updates to Bokeh apps.
(default: None)
See :class:`~bokeh.document.events.DocumentChangedEvent`
for more details.
'''
super(ColumnsPatchedEvent, self).__init__(document, setter)
self.column_source = column_source
self.patches = patches
[docs] def dispatch(self, receiver):
''' Dispatch handling of this event to a receiver.
This method will invoke ``receiver._columns_patched`` if it exists.
'''
super(ColumnsPatchedEvent, self).dispatch(receiver)
if hasattr(receiver, '_columns_patched'):
receiver._columns_patched(self)
[docs] def generate(self, references, buffers):
''' Create a JSON representation of this event suitable for sending
to clients.
.. code-block:: python
{
'kind' : 'ColumnsPatched'
'column_source' : <reference to a CDS>
'patches' : <patches to apply to column_source>
}
Args:
references (dict[str, Model]) :
If the event requires references to certain models in order to
function, they may be collected here.
**This is an "out" parameter**. The values it contains will be
modified in-place.
buffers (set) :
If the event needs to supply any additional Bokeh protocol
buffers, they may be added to this set.
**This is an "out" parameter**. The values it contains will be
modified in-place.
'''
return { 'kind' : 'ColumnsPatched',
'column_source' : self.column_source.ref,
'patches' : self.patches }
[docs]class TitleChangedEvent(DocumentPatchedEvent):
''' A concrete event representing a change to the title of a Bokeh
Document.
'''
[docs] def __init__(self, document, title, setter=None):
'''
Args:
document (Document) :
A Bokeh document that is to be updated.
title (str) :
The new title to set on the Document
setter (ClientSession or ServerSession or None, optional) :
This is used to prevent "boomerang" updates to Bokeh apps.
(default: None)
See :class:`~bokeh.document.events.DocumentChangedEvent`
for more details.
'''
super(TitleChangedEvent, self).__init__(document, setter)
self.title = title
[docs] def generate(self, references, buffers):
''' Create a JSON representation of this event suitable for sending
to clients.
.. code-block:: python
{
'kind' : 'TitleChanged'
'title' : <new title to set>
}
Args:
references (dict[str, Model]) :
If the event requires references to certain models in order to
function, they may be collected here.
**This is an "out" parameter**. The values it contains will be
modified in-place.
buffers (set) :
If the event needs to supply any additional Bokeh protocol
buffers, they may be added to this set.
**This is an "out" parameter**. The values it contains will be
modified in-place.
'''
return { 'kind' : 'TitleChanged',
'title' : self.title }
[docs]class RootAddedEvent(DocumentPatchedEvent):
''' A concrete event representing a change to add a new Model to a
Document's collection of "root" models.
'''
[docs] def __init__(self, document, model, setter=None):
'''
Args:
document (Document) :
A Bokeh document that is to be updated.
model (Model) :
The Bokeh Model to add as a Document root.
setter (ClientSession or ServerSession or None, optional) :
This is used to prevent "boomerang" updates to Bokeh apps.
(default: None)
See :class:`~bokeh.document.events.DocumentChangedEvent`
for more details.
'''
super(RootAddedEvent, self).__init__(document, setter)
self.model = model
[docs] def generate(self, references, buffers):
''' Create a JSON representation of this event suitable for sending
to clients.
.. code-block:: python
{
'kind' : 'RootAdded'
'title' : <reference to a Model>
}
Args:
references (dict[str, Model]) :
If the event requires references to certain models in order to
function, they may be collected here.
**This is an "out" parameter**. The values it contains will be
modified in-place.
buffers (set) :
If the event needs to supply any additional Bokeh protocol
buffers, they may be added to this set.
**This is an "out" parameter**. The values it contains will be
modified in-place.
'''
references.update(self.model.references())
return { 'kind' : 'RootAdded',
'model' : self.model.ref }
[docs]class RootRemovedEvent(DocumentPatchedEvent):
''' A concrete event representing a change to remove an existing Model
from a Document's collection of "root" models.
'''
[docs] def __init__(self, document, model, setter=None):
'''
Args:
document (Document) :
A Bokeh document that is to be updated.
model (Model) :
The Bokeh Model to remove as a Document root.
setter (ClientSession or ServerSession or None, optional) :
This is used to prevent "boomerang" updates to Bokeh apps.
(default: None)
See :class:`~bokeh.document.events.DocumentChangedEvent`
for more details.
'''
super(RootRemovedEvent, self).__init__(document, setter)
self.model = model
[docs] def generate(self, references, buffers):
''' Create a JSON representation of this event suitable for sending
to clients.
.. code-block:: python
{
'kind' : 'RootRemoved'
'title' : <reference to a Model>
}
Args:
references (dict[str, Model]) :
If the event requires references to certain models in order to
function, they may be collected here.
**This is an "out" parameter**. The values it contains will be
modified in-place.
buffers (set) :
If the event needs to supply any additional Bokeh protocol
buffers, they may be added to this set.
**This is an "out" parameter**. The values it contains will be
modified in-place.
'''
return { 'kind' : 'RootRemoved',
'model' : self.model.ref }
[docs]class SessionCallbackAdded(DocumentChangedEvent):
''' A concrete event representing a change to add a new callback (e.g.
periodic, timeout, or "next tick") to a Document.
'''
[docs] def __init__(self, document, callback):
'''
Args:
document (Document) :
A Bokeh document that is to be updated.
callback (SessionCallback) :
The callback to add
'''
super(SessionCallbackAdded, self).__init__(document)
self.callback = callback
[docs] def dispatch(self, receiver):
''' Dispatch handling of this event to a receiver.
This method will invoke ``receiver._session_callback_added`` if
it exists.
'''
super(SessionCallbackAdded, self).dispatch(receiver)
if hasattr(receiver, '_session_callback_added'):
receiver._session_callback_added(self)
[docs]class SessionCallbackRemoved(DocumentChangedEvent):
''' A concrete event representing a change to remove an existing callback
(e.g. periodic, timeout, or "next tick") from a Document.
'''
[docs] def __init__(self, document, callback):
'''
Args:
document (Document) :
A Bokeh document that is to be updated.
callback (SessionCallback) :
The callback to remove
'''
super(SessionCallbackRemoved, self).__init__(document)
self.callback = callback
[docs] def dispatch(self, receiver):
''' Dispatch handling of this event to a receiver.
This method will invoke ``receiver._session_callback_removed`` if
it exists.
'''
super(SessionCallbackRemoved, self).dispatch(receiver)
if hasattr(receiver, '_session_callback_removed'):
receiver._session_callback_removed(self)
