"""
Declares Syncable and Reactive classes which provides baseclasses
for Panel components which sync their state with one or more bokeh
models rendered on the frontend.
"""
import difflib
import datetime as dt
import logging
import re
import sys
import textwrap
from collections import Counter, defaultdict, namedtuple
from functools import partial
import bleach
import numpy as np
import param
from bokeh.model import DataModel
from param.parameterized import ParameterizedMetaclass, Watcher
from pprint import pformat
from .io.document import unlocked
from .io.model import hold
from .io.notebook import push
from .io.state import set_curdoc, state
from .models.reactive_html import (
ReactiveHTML as _BkReactiveHTML, ReactiveHTMLParser
)
from .util import edit_readonly, escape, updating
from .viewable import Layoutable, Renderable, Viewable
log = logging.getLogger('panel.reactive')
LinkWatcher = namedtuple("Watcher", Watcher._fields+('target', 'links', 'transformed', 'bidirectional_watcher'))
class Syncable(Renderable):
"""
Syncable is an extension of the Renderable object which can not
only render to a bokeh model but also sync the parameters on the
object with the properties on the model.
In order to bi-directionally link parameters with bokeh model
instances the _link_params and _link_props methods define
callbacks triggered when either the parameter or bokeh property
values change. Since there may not be a 1-to-1 mapping between
parameter and the model property the _process_property_change and
_process_param_change may be overridden to apply any necessary
transformations.
"""
# Timeout if a notebook comm message is swallowed
_timeout = 20000
# Timeout before the first event is processed
_debounce = 50
# Property changes which should not be debounced
_priority_changes = []
# Any parameters that require manual updates handling for the models
# e.g. parameters which affect some sub-model
_manual_params = []
# Mapping from parameter name to bokeh model property name
_rename = {}
# Allows defining a mapping from model property name to a JS code
# snippet that transforms the object before serialization
_js_transforms = {}
# Transforms from input value to bokeh property value
_source_transforms = {}
_target_transforms = {}
__abstract = True
def __init__(self, **params):
super().__init__(**params)
# Useful when updating model properties which trigger potentially
# recursive events
self._updating = False
# A dictionary of current property change events
self._events = {}
# Any watchers associated with links between two objects
self._links = []
self._link_params()
# A dictionary of bokeh property changes being processed
self._changing = {}
# Sets up watchers to process manual updates to models
if self._manual_params:
self.param.watch(self._update_manual, self._manual_params)
#----------------------------------------------------------------
# Model API
#----------------------------------------------------------------
def _process_property_change(self, msg):
"""
Transform bokeh model property changes into parameter updates.
Should be overridden to provide appropriate mapping between
parameter value and bokeh model change. By default uses the
_rename class level attribute to map between parameter and
property names.
"""
inverted = {v: k for k, v in self._rename.items()}
return {inverted.get(k, k): v for k, v in msg.items()}
def _process_param_change(self, msg):
"""
Transform parameter changes into bokeh model property updates.
Should be overridden to provide appropriate mapping between
parameter value and bokeh model change. By default uses the
_rename class level attribute to map between parameter and
property names.
"""
properties = {self._rename.get(k, k): v for k, v in msg.items()
if self._rename.get(k, False) is not None}
if 'width' in properties and self.sizing_mode is None:
properties['min_width'] = properties['width']
if 'height' in properties and self.sizing_mode is None:
properties['min_height'] = properties['height']
return properties
@property
def _linkable_params(self):
"""
Parameters that can be linked in JavaScript via source
transforms.
"""
return [p for p in self._synced_params if self._rename.get(p, False) is not None
and self._source_transforms.get(p, False) is not None] + ['loading']
@property
def _synced_params(self):
"""
Parameters which are synced with properties using transforms
applied in the _process_param_change method.
"""
ignored = ['default_layout', 'loading']
return [p for p in self.param if p not in self._manual_params+ignored]
def _init_params(self):
return {k: v for k, v in self.param.values().items()
if k in self._synced_params and v is not None}
def _link_params(self):
params = self._synced_params
if params:
watcher = self.param.watch(self._param_change, params)
self._callbacks.append(watcher)
def _link_props(self, model, properties, doc, root, comm=None):
from .config import config
ref = root.ref['id']
if config.embed:
return
for p in properties:
if isinstance(p, tuple):
_, p = p
m = model
if '.' in p:
*subpath, p = p.split('.')
for sp in subpath:
m = getattr(m, sp)
else:
subpath = None
if comm:
m.on_change(p, partial(self._comm_change, doc, ref, comm, subpath))
else:
m.on_change(p, partial(self._server_change, doc, ref, subpath))
def _manual_update(self, events, model, doc, root, parent, comm):
"""
Method for handling any manual update events, i.e. events triggered
by changes in the manual params.
"""
def _update_manual(self, *events):
for ref, (model, parent) in self._models.items():
if ref not in state._views or ref in state._fake_roots:
continue
viewable, root, doc, comm = state._views[ref]
if comm or state._unblocked(doc):
with unlocked():
self._manual_update(events, model, doc, root, parent, comm)
if comm and 'embedded' not in root.tags:
push(doc, comm)
else:
cb = partial(self._manual_update, events, model, doc, root, parent, comm)
if doc.session_context:
doc.add_next_tick_callback(cb)
else:
cb()
def _apply_update(self, events, msg, model, ref):
if ref not in state._views or ref in state._fake_roots:
return
viewable, root, doc, comm = state._views[ref]
if comm or not doc.session_context or state._unblocked(doc):
with unlocked():
self._update_model(events, msg, root, model, doc, comm)
if comm and 'embedded' not in root.tags:
push(doc, comm)
else:
cb = partial(self._update_model, events, msg, root, model, doc, comm)
doc.add_next_tick_callback(cb)
def _update_model(self, events, msg, root, model, doc, comm):
ref = root.ref['id']
self._changing[ref] = attrs = [
attr for attr, value in msg.items()
if not model.lookup(attr).property.matches(getattr(model, attr), value)
]
try:
model.update(**msg)
finally:
changing = [
attr for attr in self._changing.get(ref, [])
if attr not in attrs
]
if changing:
self._changing[ref] = changing
elif ref in self._changing:
del self._changing[ref]
def _cleanup(self, root):
super()._cleanup(root)
ref = root.ref['id']
self._models.pop(ref, None)
comm, client_comm = self._comms.pop(ref, (None, None))
if comm:
try:
comm.close()
except Exception:
pass
if client_comm:
try:
client_comm.close()
except Exception:
pass
def _param_change(self, *events):
msgs = []
for event in events:
msg = self._process_param_change({event.name: event.new})
if msg:
msgs.append(msg)
events = {event.name: event for event in events}
msg = {k: v for msg in msgs for k, v in msg.items()}
if not msg:
return
for ref, (model, _) in self._models.copy().items():
self._apply_update(events, msg, model, ref)
def _process_events(self, events):
self._log('received events %s', events)
busy = state.busy
with edit_readonly(state):
state.busy = True
events = self._process_property_change(events)
try:
with edit_readonly(self):
self_events = {k: v for k, v in events.items() if '.' not in k}
self.param.update(**self_events)
for k, v in self_events.items():
if '.' not in k:
continue
*subpath, p = k.split('.')
obj = self
for sp in subpath:
obj = getattr(obj, sp)
with edit_readonly(obj):
obj.param.update(**{p: v})
except Exception:
if len(events)>1:
msg_end = f" changing properties {pformat(events)} \n"
elif len(events)==1:
msg_end = f" changing property {pformat(events)} \n"
else:
msg_end = "\n"
log.exception(f'Callback failed for object named "{self.name}"{msg_end}')
raise
finally:
self._log('finished processing events %s', events)
with edit_readonly(state):
state.busy = busy
def _process_bokeh_event(self, event):
self._log('received bokeh event %s', event)
busy = state.busy
with edit_readonly(state):
state.busy = True
try:
self._process_event(event)
finally:
self._log('finished processing bokeh event %s', event)
with edit_readonly(state):
state.busy = busy
async def _change_coroutine(self, doc=None):
if state._thread_pool:
state._thread_pool.submit(self._change_event, doc)
else:
with set_curdoc(doc):
self._change_event(doc)
async def _event_coroutine(self, event, doc):
if state._thread_pool:
state._thread_pool.submit(self._process_bokeh_event, event)
else:
with set_curdoc(doc):
self._process_bokeh_event(event)
def _change_event(self, doc=None):
try:
state.curdoc = doc
events = self._events
self._events = {}
self._process_events(events)
finally:
state.curdoc = None
def _schedule_change(self, doc, comm):
with hold(doc, comm=comm):
self._change_event(doc)
def _comm_change(self, doc, ref, comm, subpath, attr, old, new):
if subpath:
attr = f'{subpath}.{attr}'
if attr in self._changing.get(ref, []):
self._changing[ref].remove(attr)
return
self._events.update({attr: new})
if state._thread_pool:
state._thread_pool.submit(self._schedule_change, doc, comm)
else:
self._schedule_change(doc, comm)
def _comm_event(self, event):
if state._thread_pool:
state._thread_pool.submit(self._process_bokeh_event, event)
else:
self._process_bokeh_event(event)
def _server_event(self, doc, event):
if doc.session_context and not state._unblocked(doc):
doc.add_next_tick_callback(
partial(self._event_coroutine, event, doc)
)
else:
self._comm_event(event)
def _server_change(self, doc, ref, subpath, attr, old, new):
if subpath:
attr = f'{subpath}.{attr}'
if attr in self._changing.get(ref, []):
self._changing[ref].remove(attr)
return
processing = bool(self._events)
self._events.update({attr: new})
if processing:
return
if doc.session_context:
cb = partial(self._change_coroutine, doc)
if attr in self._priority_changes:
doc.add_next_tick_callback(cb)
else:
doc.add_timeout_callback(cb, self._debounce)
else:
self._change_event(doc)
class Reactive(Syncable, Viewable):
"""
Reactive is a Viewable object that also supports syncing between
the objects parameters and the underlying bokeh model either via
the defined pyviz_comms.Comm type or using bokeh server.
In addition it defines various methods which make it easy to link
the parameters to other objects.
"""
#----------------------------------------------------------------
# Public API
#----------------------------------------------------------------
def link(self, target, callbacks=None, bidirectional=False, **links):
"""
Links the parameters on this object to attributes on another
object in Python. Supports two modes, either specify a mapping
between the source and target object parameters as keywords or
provide a dictionary of callbacks which maps from the source
parameter to a callback which is triggered when the parameter
changes.
Arguments
---------
target: object
The target object of the link.
callbacks: dict
Maps from a parameter in the source object to a callback.
bidirectional: boolean
Whether to link source and target bi-directionally
**links: dict
Maps between parameters on this object to the parameters
on the supplied object.
"""
if links and callbacks:
raise ValueError('Either supply a set of parameters to '
'link as keywords or a set of callbacks, '
'not both.')
elif not links and not callbacks:
raise ValueError('Declare parameters to link or a set of '
'callbacks, neither was defined.')
elif callbacks and bidirectional:
raise ValueError('Bidirectional linking not supported for '
'explicit callbacks. You must define '
'separate callbacks for each direction.')
_updating = []
def link(*events):
for event in events:
if event.name in _updating: continue
_updating.append(event.name)
try:
if callbacks:
callbacks[event.name](target, event)
else:
setattr(target, links[event.name], event.new)
finally:
_updating.pop(_updating.index(event.name))
params = list(callbacks) if callbacks else list(links)
cb = self.param.watch(link, params)
bidirectional_watcher = None
if bidirectional:
_reverse_updating = []
reverse_links = {v: k for k, v in links.items()}
def reverse_link(*events):
for event in events:
if event.name in _reverse_updating: continue
_reverse_updating.append(event.name)
try:
setattr(self, reverse_links[event.name], event.new)
finally:
_reverse_updating.remove(event.name)
bidirectional_watcher = target.param.watch(reverse_link, list(reverse_links))
link_args = tuple(cb)
# Compatibility with Param versions where precedence is dropped
# from iterator for backward compatibility with older Panel versions
if 'precedence' in Watcher._fields and len(link_args) < len(Watcher._fields):
link_args += (cb.precedence,)
link = LinkWatcher(*(link_args+(target, links, callbacks is not None, bidirectional_watcher)))
self._links.append(link)
return cb
def controls(self, parameters=[], jslink=True, **kwargs):
"""
Creates a set of widgets which allow manipulating the parameters
on this instance. By default all parameters which support
linking are exposed, but an explicit list of parameters can
be provided.
Arguments
---------
parameters: list(str)
An explicit list of parameters to return controls for.
jslink: bool
Whether to use jslinks instead of Python based links.
This does not allow using all types of parameters.
kwargs: dict
Additional kwargs to pass to the Param pane(s) used to
generate the controls widgets.
Returns
-------
A layout of the controls
"""
from .param import Param
from .layout import Tabs, WidgetBox
from .widgets import LiteralInput
if parameters:
linkable = parameters
elif jslink:
linkable = self._linkable_params
else:
linkable = list(self.param)
params = [p for p in linkable if p not in Viewable.param]
controls = Param(self.param, parameters=params, default_layout=WidgetBox,
name='Controls', **kwargs)
layout_params = [p for p in linkable if p in Viewable.param]
if 'name' not in layout_params and self._rename.get('name', False) is not None and not parameters:
layout_params.insert(0, 'name')
style = Param(self.param, parameters=layout_params, default_layout=WidgetBox,
name='Layout', **kwargs)
if jslink:
for p in params:
widget = controls._widgets[p]
widget.jslink(self, value=p, bidirectional=True)
if isinstance(widget, LiteralInput):
widget.serializer = 'json'
for p in layout_params:
widget = style._widgets[p]
widget.jslink(self, value=p, bidirectional=p != 'loading')
if isinstance(widget, LiteralInput):
widget.serializer = 'json'
if params and layout_params:
return Tabs(controls.layout[0], style.layout[0])
elif params:
return controls.layout[0]
return style.layout[0]
def jscallback(self, args={}, **callbacks):
"""
Allows defining a JS callback to be triggered when a property
changes on the source object. The keyword arguments define the
properties that trigger a callback and the JS code that gets
executed.
Arguments
----------
args: dict
A mapping of objects to make available to the JS callback
**callbacks: dict
A mapping between properties on the source model and the code
to execute when that property changes
Returns
-------
callback: Callback
The Callback which can be used to disable the callback.
"""
from .links import Callback
for k, v in list(callbacks.items()):
callbacks[k] = self._rename.get(v, v)
return Callback(self, code=callbacks, args=args)
def jslink(self, target, code=None, args=None, bidirectional=False, **links):
"""
Links properties on the source object to those on the target
object in JS code. Supports two modes, either specify a
mapping between the source and target model properties as
keywords or provide a dictionary of JS code snippets which
maps from the source parameter to a JS code snippet which is
executed when the property changes.
Arguments
----------
target: HoloViews object or bokeh Model or panel Viewable
The target to link the value to.
code: dict
Custom code which will be executed when the widget value
changes.
bidirectional: boolean
Whether to link source and target bi-directionally
**links: dict
A mapping between properties on the source model and the
target model property to link it to.
Returns
-------
link: GenericLink
The GenericLink which can be used unlink the widget and
the target model.
"""
if links and code:
raise ValueError('Either supply a set of properties to '
'link as keywords or a set of JS code '
'callbacks, not both.')
elif not links and not code:
raise ValueError('Declare parameters to link or a set of '
'callbacks, neither was defined.')
if args is None:
args = {}
from .links import Link, assert_source_syncable, assert_target_syncable
mapping = code or links
assert_source_syncable(self, mapping)
if isinstance(target, Syncable) and code is None:
assert_target_syncable(self, target, mapping)
return Link(self, target, properties=links, code=code, args=args,
bidirectional=bidirectional)
class SyncableData(Reactive):
"""
A baseclass for components which sync one or more data parameters
with the frontend via a ColumnDataSource.
"""
selection = param.List(default=[], doc="""
The currently selected rows in the data.""")
# Parameters which when changed require an update of the data
_data_params = []
_rename = {'selection': None}
__abstract = True
def __init__(self, **params):
super().__init__(**params)
self._data = None
self._processed = None
self.param.watch(self._validate, self._data_params)
if self._data_params:
self.param.watch(self._update_cds, self._data_params)
self.param.watch(self._update_selected, 'selection')
self._validate()
self._update_cds()
def _validate(self, *events):
"""
Allows implementing validation for the data parameters.
"""
def _get_data(self):
"""
Implemented by subclasses converting data parameter(s) into
a ColumnDataSource compatible data dictionary.
Returns
-------
processed: object
Raw data after pre-processing (e.g. after filtering)
data: dict
Dictionary of columns used to instantiate and update the
ColumnDataSource
"""
def _update_column(self, column, array):
"""
Implemented by subclasses converting changes in columns to
changes in the data parameter.
Parameters
----------
column: str
The name of the column to update.
array: numpy.ndarray
The array data to update the column with.
"""
data = getattr(self, self._data_params[0])
data[column] = array
if self._processed is not None:
self._processed[column] = array
def _update_data(self, data):
self.param.update(**{self._data_params[0]: data})
def _manual_update(self, events, model, doc, root, parent, comm):
for event in events:
if event.type == 'triggered' and self._updating:
continue
elif hasattr(self, '_update_' + event.name):
getattr(self, '_update_' + event.name)(model)
@updating
def _update_cds(self, *events):
self._processed, self._data = self._get_data()
msg = {'data': self._data}
for ref, (m, _) in self._models.items():
self._apply_update(events, msg, m.source, ref)
@updating
def _update_selected(self, *events, indices=None):
indices = self.selection if indices is None else indices
msg = {'indices': indices}
for ref, (m, _) in self._models.items():
self._apply_update(events, msg, m.source.selected, ref)
def _apply_stream(self, ref, model, stream, rollover):
self._changing[ref] = ['data']
try:
model.source.stream(stream, rollover)
finally:
del self._changing[ref]
@updating
def _stream(self, stream, rollover=None):
self._processed, _ = self._get_data()
for ref, (m, _) in self._models.items():
if ref not in state._views or ref in state._fake_roots:
continue
viewable, root, doc, comm = state._views[ref]
if comm or not doc.session_context or state._unblocked(doc):
with unlocked():
m.source.stream(stream, rollover)
if comm and 'embedded' not in root.tags:
push(doc, comm)
else:
cb = partial(self._apply_stream, ref, m, stream, rollover)
doc.add_next_tick_callback(cb)
def _apply_patch(self, ref, model, patch):
self._changing[ref] = ['data']
try:
model.source.patch(patch)
finally:
del self._changing[ref]
@updating
def _patch(self, patch):
for ref, (m, _) in self._models.items():
if ref not in state._views or ref in state._fake_roots:
continue
viewable, root, doc, comm = state._views[ref]
if comm or not doc.session_context or state._unblocked(doc):
with unlocked():
m.source.patch(patch)
if comm and 'embedded' not in root.tags:
push(doc, comm)
else:
cb = partial(self._apply_patch, ref, m, patch)
doc.add_next_tick_callback(cb)
def _update_manual(self, *events):
"""
Skip events triggered internally
"""
processed_events = []
for e in events:
if e.name == self._data_params[0] and e.type == 'triggered' and self._updating:
continue
processed_events.append(e)
super()._update_manual(*processed_events)
def stream(self, stream_value, rollover=None, reset_index=True):
"""
Streams (appends) the `stream_value` provided to the existing
value in an efficient manner.
Arguments
---------
stream_value: (Union[pd.DataFrame, pd.Series, Dict])
The new value(s) to append to the existing value.
rollover: int
A maximum column size, above which data from the start of
the column begins to be discarded. If None, then columns
will continue to grow unbounded.
reset_index (bool, default=True):
If True and the stream_value is a DataFrame, then its index
is reset. Helps to keep the index unique and named `index`.
Raises
------
ValueError: Raised if the stream_value is not a supported type.
Examples
--------
Stream a Series to a DataFrame
>>> value = pd.DataFrame({"x": [1, 2], "y": ["a", "b"]})
>>> obj = DataComponent(value)
>>> stream_value = pd.Series({"x": 4, "y": "d"})
>>> obj.stream(stream_value)
>>> obj.value.to_dict("list")
{'x': [1, 2, 4], 'y': ['a', 'b', 'd']}
Stream a Dataframe to a Dataframe
>>> value = pd.DataFrame({"x": [1, 2], "y": ["a", "b"]})
>>> obj = DataComponent(value)
>>> stream_value = pd.DataFrame({"x": [3, 4], "y": ["c", "d"]})
>>> obj.stream(stream_value)
>>> obj.value.to_dict("list")
{'x': [1, 2, 3, 4], 'y': ['a', 'b', 'c', 'd']}
Stream a Dictionary row to a DataFrame
>>> value = pd.DataFrame({"x": [1, 2], "y": ["a", "b"]})
>>> tabulator = DataComponent(value)
>>> stream_value = {"x": 4, "y": "d"}
>>> obj.stream(stream_value)
>>> obj.value.to_dict("list")
{'x': [1, 2, 4], 'y': ['a', 'b', 'd']}
Stream a Dictionary of Columns to a Dataframe
>>> value = pd.DataFrame({"x": [1, 2], "y": ["a", "b"]})
>>> obj = DataComponent(value)
>>> stream_value = {"x": [3, 4], "y": ["c", "d"]}
>>> obj.stream(stream_value)
>>> obj.value.to_dict("list")
{'x': [1, 2, 3, 4], 'y': ['a', 'b', 'c', 'd']}
"""
if 'pandas' in sys.modules:
import pandas as pd
else:
pd = None
if pd and isinstance(stream_value, pd.DataFrame):
if isinstance(self._processed, dict):
self.stream(stream_value.to_dict(), rollover)
return
if reset_index:
value_index_start = self._processed.index.max() + 1
stream_value = stream_value.reset_index(drop=True)
stream_value.index += value_index_start
combined = pd.concat([self._processed, stream_value])
if rollover is not None:
combined = combined.iloc[-rollover:]
with param.discard_events(self):
self._update_data(combined)
try:
self._updating = True
self.param.trigger(self._data_params[0])
finally:
self._updating = False
self._stream(stream_value, rollover)
elif pd and isinstance(stream_value, pd.Series):
if isinstance(self._processed, dict):
self.stream({k: [v] for k, v in stream_value.to_dict().items()}, rollover)
return
value_index_start = self._processed.index.max() + 1
self._processed.loc[value_index_start] = stream_value
with param.discard_events(self):
self._update_data(self._processed)
self._stream(self._processed.iloc[-1:], rollover)
elif isinstance(stream_value, dict):
if isinstance(self._processed, dict):
if not all(col in stream_value for col in self._data):
raise ValueError("Stream update must append to all columns.")
for col, array in stream_value.items():
combined = np.concatenate([self._data[col], array])
if rollover is not None:
combined = combined[-rollover:]
self._update_column(col, combined)
self._stream(stream_value, rollover)
else:
try:
stream_value = pd.DataFrame(stream_value)
except ValueError:
stream_value = pd.Series(stream_value)
self.stream(stream_value)
else:
raise ValueError("The stream value provided is not a DataFrame, Series or Dict!")
def patch(self, patch_value):
"""
Efficiently patches (updates) the existing value with the `patch_value`.
Arguments
---------
patch_value: (Union[pd.DataFrame, pd.Series, Dict])
The value(s) to patch the existing value with.
Raises
------
ValueError: Raised if the patch_value is not a supported type.
Examples
--------
Patch a DataFrame with a Dictionary row.
>>> value = pd.DataFrame({"x": [1, 2], "y": ["a", "b"]})
>>> obj = DataComponent(value)
>>> patch_value = {"x": [(0, 3)]}
>>> obj.patch(patch_value)
>>> obj.value.to_dict("list")
{'x': [3, 2], 'y': ['a', 'b']}
Patch a Dataframe with a Dictionary of Columns.
>>> value = pd.DataFrame({"x": [1, 2], "y": ["a", "b"]})
>>> obj = DataComponent(value)
>>> patch_value = {"x": [(slice(2), (3,4))], "y": [(1,'d')]}
>>> obj.patch(patch_value)
>>> obj.value.to_dict("list")
{'x': [3, 4], 'y': ['a', 'd']}
Patch a DataFrame with a Series. Please note the index is used in the update.
>>> value = pd.DataFrame({"x": [1, 2], "y": ["a", "b"]})
>>> obj = DataComponent(value)
>>> patch_value = pd.Series({"index": 1, "x": 4, "y": "d"})
>>> obj.patch(patch_value)
>>> obj.value.to_dict("list")
{'x': [1, 4], 'y': ['a', 'd']}
Patch a Dataframe with a Dataframe. Please note the index is used in the update.
>>> value = pd.DataFrame({"x": [1, 2], "y": ["a", "b"]})
>>> obj = DataComponent(value)
>>> patch_value = pd.DataFrame({"x": [3, 4], "y": ["c", "d"]})
>>> obj.patch(patch_value)
>>> obj.value.to_dict("list")
{'x': [3, 4], 'y': ['c', 'd']}
"""
if self._processed is None or isinstance(patch_value, dict):
self._patch(patch_value)
return
if 'pandas' in sys.modules:
import pandas as pd
else:
pd = None
data = getattr(self, self._data_params[0])
if pd and isinstance(patch_value, pd.DataFrame):
patch_value_dict = {}
for column in patch_value.columns:
patch_value_dict[column] = []
for index in patch_value.index:
patch_value_dict[column].append((index, patch_value.loc[index, column]))
self.patch(patch_value_dict)
elif pd and isinstance(patch_value, pd.Series):
if "index" in patch_value: # Series orient is row
patch_value_dict = {
k: [(patch_value["index"], v)] for k, v in patch_value.items()
}
patch_value_dict.pop("index")
else: # Series orient is column
patch_value_dict = {
patch_value.name: [(index, value) for index, value in patch_value.items()]
}
self.patch(patch_value_dict)
elif isinstance(patch_value, dict):
for k, v in patch_value.items():
for index, patch in v:
if pd and isinstance(self._processed, pd.DataFrame):
data.loc[index, k] = patch
else:
data[k][index] = patch
self._updating = True
try:
self._patch(patch_value)
finally:
self._updating = False
else:
raise ValueError(
f"Patching with a patch_value of type {type(patch_value).__name__} "
"is not supported. Please provide a DataFrame, Series or Dict."
)
class ReactiveData(SyncableData):
"""
An extension of SyncableData which bi-directionally syncs a data
parameter between frontend and backend using a ColumnDataSource.
"""
def __init__(self, **params):
super().__init__(**params)
self._old = None
def _update_selection(self, indices):
self.selection = indices
def _convert_column(self, values, old_values):
dtype = old_values.dtype
if dtype.kind == 'M':
if values.dtype.kind in 'if':
values = (values * 10e5).astype(dtype)
elif dtype.kind == 'O':
if (all(isinstance(ov, dt.date) for ov in old_values) and
not all(isinstance(iv, dt.date) for iv in values)):
new_values = []
for iv in values:
if isinstance(iv, dt.datetime):
iv = iv.date()
elif not isinstance(iv, dt.date):
iv = dt.date.fromtimestamp(iv/1000)
new_values.append(iv)
values = new_values
else:
values = values.astype(dtype)
return values
def _process_data(self, data):
if self._updating:
return
# Get old data to compare to
old_raw, old_data = self._get_data()
self._old = old_raw = old_raw.copy()
if hasattr(old_raw, 'columns'):
columns = list(old_raw.columns)
else:
columns = list(old_raw)
updated = False
for col, values in data.items():
col = self._renamed_cols.get(col, col)
if col in self.indexes or col not in columns:
continue
if isinstance(values, dict):
sorted_values = sorted(values.items(), key=lambda it: int(it[0]))
values = [v for _, v in sorted_values]
values = self._convert_column(
np.asarray(values), old_raw[col]
)
try:
isequal = (old_raw[col] == values).all()
except Exception:
isequal = False
if not isequal:
self._update_column(col, values)
updated = True
# If no columns were updated we don't have to sync data
if not updated:
return
# Ensure we trigger events
self._updating = True
old_data = getattr(self, self._data_params[0])
try:
if old_data is self.value:
with param.discard_events(self):
self.value = old_raw
self.value = old_data
else:
self.param.trigger('value')
finally:
self._updating = False
# Ensure that if the data was changed in a user
# callback, we still send the updated data
if old_data is not self.value:
self._update_cds()
def _process_events(self, events):
if 'data' in events:
self._process_data(events.pop('data'))
if 'indices' in events:
self._updating = True
try:
self._update_selection(events.pop('indices'))
finally:
self._updating = False
super(ReactiveData, self)._process_events(events)
class ReactiveHTMLMetaclass(ParameterizedMetaclass):
"""
Parses the ReactiveHTML._template of the class and initializes
variables, callbacks and the data model to sync the parameters and
HTML attributes.
"""
_loaded_extensions = set()
_name_counter = Counter()
_script_regex = r"script\([\"|'](.*)[\"|']\)"
def __init__(mcs, name, bases, dict_):
from .io.datamodel import PARAM_MAPPING, construct_data_model
mcs.__original_doc__ = mcs.__doc__
ParameterizedMetaclass.__init__(mcs, name, bases, dict_)
cls_name = mcs.__name__
# Validate _child_config
for name, child_type in mcs._child_config.items():
if name not in mcs.param:
raise ValueError(
f"{cls_name}._child_config for {name!r} does not "
"match any parameters. Ensure the name of each "
"child config matches one of the parameters."
)
elif child_type not in ('model', 'template', 'literal'):
raise ValueError(
f"{cls_name}._child_config for {name!r} child "
"parameter declares unknown type {child_type!r}. "
f"The '_child_config' mode must be one of 'model', "
"'template' or 'literal'."
)
mcs._parser = ReactiveHTMLParser(mcs)
mcs._parser.feed(mcs._template)
# Ensure syntactically valid jinja2 for loops
if mcs._parser._open_for:
raise ValueError(
f"{cls_name}._template contains for loop without closing {{% endfor %}} statement."
)
# Ensure there are no open tags
if mcs._parser._node_stack:
raise ValueError(
f"{cls_name}._template contains tags which were never "
"closed. Ensure all tags in your template have a "
"matching closing tag, e.g. if there is a tag
, "
"ensure there is a matching
tag."
)
mcs._node_callbacks = {}
mcs._inline_callbacks = []
for node, attrs in mcs._parser.attrs.items():
for (attr, parameters, template) in attrs:
for p in parameters:
if p in mcs.param or '.' in p:
continue
if re.match(mcs._script_regex, p):
name = re.findall(mcs._script_regex, p)[0]
if name not in mcs._scripts:
raise ValueError(
f"{cls_name}._template inline callback "
f"references unknown script {name!r}, "
"ensure the referenced script is declared"
"in the _scripts dictionary."
)
if node not in mcs._node_callbacks:
mcs._node_callbacks[node] = []
mcs._node_callbacks[node].append((attr, p))
elif hasattr(mcs, p):
if node not in mcs._node_callbacks:
mcs._node_callbacks[node] = []
mcs._node_callbacks[node].append((attr, p))
mcs._inline_callbacks.append((node, attr, p))
else:
matches = difflib.get_close_matches(p, dir(mcs))
raise ValueError(
f"{cls_name}._template references unknown "
f"parameter or method '{p}', similar parameters "
f"and methods include {matches}."
)
ignored = list(Reactive.param)
types = {}
for child in mcs._parser.children.values():
cparam = mcs.param[child]
if mcs._child_config.get(child) == 'literal':
types[child] = param.String
elif (type(cparam) not in PARAM_MAPPING or
isinstance(cparam, (param.List, param.Dict, param.Tuple)) or
(isinstance(cparam, param.ClassSelector) and
isinstance(cparam.class_, type) and
(not issubclass(cparam.class_, param.Parameterized) or
issubclass(cparam.class_, Reactive)))):
# Any parameter which can be consistently serialized
# (except) Panel Reactive objects can be reflected
# on the data model
ignored.append(child)
ignored.remove('name')
# Create model with unique name
ReactiveHTMLMetaclass._name_counter[name] += 1
model_name = f'{name}{ReactiveHTMLMetaclass._name_counter[name]}'
mcs._data_model = construct_data_model(
mcs, name=model_name, ignore=ignored, types=types
)
class ReactiveHTML(Reactive, metaclass=ReactiveHTMLMetaclass):
"""
ReactiveHTML provides bi-directional syncing of arbitrary HTML
attributes and DOM properties with parameters on the subclass.
HTML templates
~~~~~~~~~~~~~~
A ReactiveHTML component is declared by providing an HTML template
on the `_template` attribute on the class. Parameters are synced by
inserting them as template variables of the form `${parameter}`,
e.g.:
${children}
will interpolate the div_class parameter on the class. In addition
to providing attributes we can also provide children to an HTML
tag. By default any parameter referenced as a child will be
treated as a Panel components to be rendered into the containing
HTML. This makes it possible to use ReactiveHTML to lay out other
components.
Children
~~~~~~~~
As mentioned above parameters may be referenced as children of a
DOM node and will, by default, be treated as Panel components to
insert on the DOM node. However by declaring a `_child_config` we
can control how the DOM nodes are treated. The `_child_config` is
indexed by parameter name and may declare one of three rendering
modes:
- model (default): Create child and render child as a Panel
component into it.
- literal: Create child and set child as its innerHTML.
- template: Set child as innerHTML of the container.
If the type is 'template' the parameter will be inserted as is and
the DOM node's innerHTML will be synced with the child parameter.
DOM Events
~~~~~~~~~~
In certain cases it is necessary to explicitly declare event
listeners on the DOM node to ensure that changes in their
properties are synced when an event is fired. To make this possible
the HTML element in question must be given a unique id, e.g.:
Now we can use this name to declare set of `_dom_events` to
subscribe to. The following will subscribe to change DOM events
on the input element:
{'input': ['change']}
Once subscribed the class may also define a method following the
`_{node}_{event}` naming convention which will fire when the DOM
event triggers, e.g. we could define a `_input_change` method.
Any such callback will be given a DOMEvent object as the first and
only argument. The DOMEvent contains information about the event
on the .data attribute and declares the type of event on the .type
attribute.
Inline callbacks
~~~~~~~~~~~~~~~~
Instead of declaring explicit DOM events Python callbacks can also
be declared inline, e.g.:
will look for an `_input_change` method on the ReactiveHTML
component and call it when the event is fired.
Additionally we can invoke pure JS scripts defined on the class, e.g.:
This will invoke the following script if it is defined on the class:
_scripts = {
'some_script': 'console.log(model, data, input, view)'
}
Scripts
~~~~~~~
In addition to declaring callbacks in Python it is also possible
to declare Javascript callbacks to execute when any synced
attribute changes. Let us say we have declared an input element
with a synced value parameter:
We can now declare a set of `_scripts`, which will fire whenever
the value updates:
_scripts = {
'value': 'console.log(model, data, input)'
}
The Javascript is provided multiple objects in its namespace
including:
* data : The data model holds the current values of the synced
parameters, e.g. data.value will reflect the current
value of the input node.
* model: The ReactiveHTML model which holds layout information
and information about the children and events.
* state: An empty state dictionary which scripts can use to
store state for the lifetime of the view.
* view: The Bokeh View class responsible for rendering the
component. This provides access to method like
`invalidate_layout` and `run_script` which allows
invoking other scripts.
* : All named DOM nodes in the HTML template, e.g. the
`input` node in the example above.
"""
_child_config = {}
_dom_events = {}
_extension_name = None
_template = ""
_scripts = {}
_script_assignment = r'data\.([^[^\d\W]\w*)[ ]*[\+,\-,\*,\\,%,\*\*,<<,>>,>>>,&,\^,|,\&\&,\|\|,\?\?]*='
__abstract = True
__css__ = None
__javascript__ = None
__javascript_modules__ = None
def __init__(self, **params):
from .pane import panel
for children_param in self._parser.children.values():
mode = self._child_config.get(children_param, 'model')
if children_param not in params or mode != 'model':
continue
child_value = params[children_param]
if isinstance(child_value, list):
children = []
for pane in child_value:
if isinstance(pane, tuple):
name, pane = pane
children.append((name, panel(pane)))
else:
children.append(panel(pane))
params[children_param] = children
elif isinstance(child_value, dict):
children = {}
for key, pane in child_value.items():
children[key] = panel(pane)
params[children_param] = children
else:
params[children_param] = panel(child_value)
super().__init__(**params)
self._attrs = {}
self._panes = {}
self._event_callbacks = defaultdict(lambda: defaultdict(list))
@classmethod
def _loaded(cls):
"""
Whether the component has been loaded.
"""
return (
cls._extension_name is None or
cls._extension_name in ReactiveHTMLMetaclass._loaded_extensions
)
def _cleanup(self, root):
for child, panes in self._panes.items():
for pane in panes:
pane._cleanup(root)
super()._cleanup(root)
@property
def _linkable_params(self):
return [p for p in super()._linkable_params if p not in self._parser.children.values()]
@property
def _child_names(self):
return {}
def _process_children(self, doc, root, model, comm, children):
return children
def _init_params(self):
ignored = list(Reactive.param)
for child in self._parser.children.values():
if self._child_config.get(child) != 'literal':
ignored.append(child)
params = {
p : getattr(self, p) for p in list(Layoutable.param)
if getattr(self, p) is not None and p != 'name'
}
data_params = {}
for k, v in self.param.values().items():
if (
(k in ignored and k != 'name') or
((self.param[k].precedence or 0) < 0) or
(isinstance(v, Viewable) and not isinstance(self.param[k], param.ClassSelector))
):
continue
if isinstance(v, str):
v = bleach.clean(v)
data_params[k] = v
html, nodes, self._attrs = self._get_template()
params.update({
'attrs': self._attrs,
'callbacks': self._node_callbacks,
'data': self._data_model(**self._process_param_change(data_params)),
'events': self._get_events(),
'html': escape(textwrap.dedent(html)),
'nodes': nodes,
'looped': [node for node, _ in self._parser.looped],
'scripts': {}
})
for trigger, scripts in self._scripts.items():
if not isinstance(scripts, list):
scripts = [scripts]
params['scripts'][trigger] = [
escape(textwrap.dedent(script).strip()) for script in scripts
]
return params
def _get_events(self):
events = {}
for node, node_events in self._dom_events.items():
if isinstance(node_events, list):
events[node] = {e: True for e in node_events}
else:
events[node] = node_events
for node, evs in self._event_callbacks.items():
events[node] = node_events = events.get(node, {})
for e in evs:
if e not in node_events:
node_events[e] = False
return events
def _get_children(self, doc, root, model, comm):
from .pane import panel
old_models = model.children
new_models = {parent: [] for parent in self._parser.children}
new_panes, internal_panes = {}, {}
for parent, children_param in self._parser.children.items():
mode = self._child_config.get(children_param, 'model')
if mode == 'literal':
new_panes[parent] = None
continue
panes = getattr(self, children_param)
if isinstance(panes, dict):
for key, value in panes.items():
panes[key] = panel(value)
elif isinstance(panes, list):
for i, pane in enumerate(panes):
panes[i] = panel(pane)
else:
panes = [panel(panes)]
new_panes[parent] = panes
if isinstance(panes, dict):
panes = list(panes.values())
internal_panes[children_param] = panes
for children_param, old_panes in self._panes.items():
for old_pane in old_panes:
if old_pane not in internal_panes.get(children_param, []):
old_pane._cleanup(root)
for parent, child_panes in new_panes.items():
children_param = self._parser.children[parent]
if isinstance(child_panes, dict):
child_panes = child_panes.values()
mode = self._child_config.get(children_param, 'model')
if mode == 'literal':
new_models[parent] = children_param
elif children_param in self._panes:
# Find existing models
old_panes = self._panes[children_param]
for i, pane in enumerate(child_panes):
if pane in old_panes and root.ref['id'] in pane._models:
child, _ = pane._models[root.ref['id']]
else:
child = pane._get_model(doc, root, model, comm)
new_models[parent].append(child)
elif parent in old_models:
# Children parameter unchanged
new_models[parent] = old_models[parent]
else:
new_models[parent] = [
pane._get_model(doc, root, model, comm)
for pane in child_panes
]
self._panes = internal_panes
return self._process_children(doc, root, model, comm, new_models)
def _get_template(self):
import jinja2
# Replace loop variables with indexed child parameter e.g.:
# {% for obj in objects %}
# ${obj}
# {% endfor %}
# becomes:
# {% for obj in objects %}
# ${objects[{{ loop.index0 }}]}
# {% endfor %}
template_string = self._template
for var, obj in self._parser.loop_map.items():
template_string = template_string.replace(
'${%s}' % var, '${%s[{{ loop.index0 }}]}' % obj)
# Add index to templated loop node ids
for dom_node, _ in self._parser.looped:
replacement = 'id="%s-{{ loop.index0 }}"' % dom_node
if f'id="{dom_node}"' in template_string:
template_string = template_string.replace(
f'id="{dom_node}"', replacement)
else:
template_string = template_string.replace(
f"id='{dom_node}'", replacement)
# Render Jinja template
template = jinja2.Template(template_string)
context = {'param': self.param, '__doc__': self.__original_doc__, 'id': id}
for parameter, value in self.param.values().items():
context[parameter] = value
if parameter in self._child_names:
context[f'{parameter}_names'] = self._child_names[parameter]
try:
html = template.render(context)
except Exception as e:
raise RuntimeError(
f"{type(self).__name__} could not render "
f"template, errored with:\n\n{type(e).__name__}: {e}.\n"
f"Full template:\n\n{template_string}"
)
# Parse templated HTML
parser = ReactiveHTMLParser(self.__class__, template=False)
parser.feed(html)
# Add node ids to all parsed nodes
for name in list(parser.nodes):
html = (
html
.replace(f"id='{name}'", f"id='{name}-${{id}}'")
.replace(f'id="{name}"', f'id="{name}-${{id}}"')
)
# Parse attrs
p_attrs = {}
for node, attrs in parser.attrs.items():
for (attr, parameters, template) in attrs:
param_attrs = []
for p in parameters:
if p in self.param or '.' in p:
param_attrs.append(p)
if node not in p_attrs:
p_attrs[node] = []
p_attrs[node].append((attr, param_attrs, template))
# Remove child node template syntax
for parent, child_name in self._parser.children.items():
if (parent, child_name) in self._parser.looped:
for i, _ in enumerate(getattr(self, child_name)):
html = html.replace('${%s[%d]}' % (child_name, i), '')
else:
html = html.replace('${%s}' % child_name, '')
return html, parser.nodes, p_attrs
def _linked_properties(self):
linked_properties = [p for pss in self._attrs.values() for _, ps, _ in pss for p in ps]
for scripts in self._scripts.values():
if not isinstance(scripts, list):
scripts = [scripts]
for script in scripts:
for p in re.findall(self._script_assignment, script):
if p not in linked_properties:
linked_properties.append(p)
for children_param in self._parser.children.values():
if children_param in self._data_model.properties():
linked_properties.append(children_param)
return linked_properties
def _get_model(self, doc, root=None, parent=None, comm=None):
properties = self._process_param_change(self._init_params())
model = _BkReactiveHTML(**properties)
if comm and not self._loaded():
self.param.warning(
f'{type(self).__name__} was not imported on instantiation and may not '
'render in a notebook. Restart the notebook kernel and '
'ensure you load it as part of the extension using:'
f'\n\npn.extension(\'{self._extension_name}\')\n'
)
elif root is not None and not self._loaded() and root.ref['id'] in state._views:
self.param.warning(
f'{type(self).__name__} was not imported on instantiation may not '
'render in the served application. Ensure you add the '
'following to the top of your application:'
f'\n\npn.extension(\'{self._extension_name}\')\n'
)
if self._extension_name:
ReactiveHTMLMetaclass._loaded_extensions.add(self._extension_name)
if not root:
root = model
for p, v in model.data.properties_with_values().items():
if isinstance(v, DataModel):
v.tags.append(f"__ref:{root.ref['id']}")
model.children = self._get_children(doc, root, model, comm)
if comm:
model.on_event('dom_event', self._comm_event)
else:
model.on_event('dom_event', partial(self._server_event, doc))
self._link_props(model.data, self._linked_properties(), doc, root, comm)
self._models[root.ref['id']] = (model, parent)
return model
def _process_event(self, event):
cb = getattr(self, f"_{event.node}_{event.data['type']}", None)
if cb is not None:
cb(event)
event_type = event.data['type']
star_cbs = self._event_callbacks.get('*', {})
node_cbs = self._event_callbacks.get(event.node, {})
inline_cbs = {attr: [getattr(self, p)] for node, attr, p in self._inline_callbacks
if node == event.node}
event_cbs = (
node_cbs.get(event_type, []) + node_cbs.get('*', []) +
star_cbs.get(event_type, []) + star_cbs.get('*', []) +
inline_cbs.get(event_type, [])
)
for cb in event_cbs:
cb(event)
def _set_on_model(self, msg, root, model):
if not msg:
return
old = self._changing.get(root.ref['id'], [])
self._changing[root.ref['id']] = [
attr for attr, value in msg.items()
if not model.lookup(attr).property.matches(getattr(model, attr), value)
]
try:
model.update(**msg)
finally:
if old:
self._changing[root.ref['id']] = old
else:
del self._changing[root.ref['id']]
def _update_model(self, events, msg, root, model, doc, comm):
child_params = self._parser.children.values()
new_children, model_msg, data_msg = {}, {}, {}
for prop, v in list(msg.items()):
if prop in child_params:
new_children[prop] = prop
if self._child_config.get(prop) == 'literal':
data_msg[prop] = bleach.clean(v)
elif prop in model.data.properties():
data_msg[prop] = v
elif prop in list(Reactive.param)+['events']:
model_msg[prop] = v
elif (
(prop in self.param) and (
((self.param[prop].precedence or 0) < 0) or
(isinstance(v, Viewable) and not isinstance(self.param[prop], param.ClassSelector))
)
):
continue
elif isinstance(v, str):
data_msg[prop] = bleach.clean(v)
else:
data_msg[prop] = v
if new_children:
if self._parser.looped:
html, nodes, self._attrs = self._get_template()
model_msg['attrs'] = self._attrs
model_msg['nodes'] = nodes
model_msg['html'] = escape(textwrap.dedent(html))
children = self._get_children(doc, root, model, comm)
else:
children = None
if children is not None:
model_msg['children'] = children
self._set_on_model(model_msg, root, model)
self._set_on_model(data_msg, root, model.data)
def on_event(self, node, event, callback):
"""
Registers a callback to be executed when the specified DOM
event is triggered on the named node. Note that the named node
must be declared in the HTML. To create a named node you must
give it an id of the form `id="name"`, where `name` will
be the node identifier.
Arguments
---------
node: str
Named node in the HTML identifiable via id of the form `id="name"`.
event: str
Name of the DOM event to add an event listener to.
callback: callable
A callable which will be given the DOMEvent object.
"""
if node not in self._parser.nodes and node != '*':
raise ValueError(f"Named node '{node}' not found. Available "
f"nodes include: {self._parser.nodes}.")
self._event_callbacks[node][event].append(callback)
events = self._get_events()
for ref, (model, _) in self._models.items():
self._apply_update([], {'events': events}, model, ref)