Source code for bokeh.model.model

#-----------------------------------------------------------------------------
# Copyright (c) 2012 - 2024, Anaconda, Inc., and Bokeh Contributors.
# All rights reserved.
#
# The full license is in the file LICENSE.txt, distributed with this software.
#-----------------------------------------------------------------------------
''' Provide a base class for all objects (called Bokeh Models) that can go in
a Bokeh |Document|.

'''
#-----------------------------------------------------------------------------
# Boilerplate
#-----------------------------------------------------------------------------
from __future__ import annotations

import logging # isort:skip
log = logging.getLogger(__name__)

#-----------------------------------------------------------------------------
# Imports
#-----------------------------------------------------------------------------

# Standard library imports
from inspect import Parameter, Signature, isclass
from typing import TYPE_CHECKING, Any, Iterable

# Bokeh imports
from ..core import properties as p
from ..core.has_props import HasProps, _default_resolver, abstract
from ..core.property._sphinx import type_link
from ..core.property.validation import without_property_validation
from ..core.serialization import ObjectRefRep, Ref, Serializer
from ..core.types import ID
from ..events import Event
from ..themes import default as default_theme
from ..util.callback_manager import EventCallbackManager, PropertyCallbackManager
from ..util.serialization import make_id
from .docs import html_repr, process_example
from .util import (
    HasDocumentRef,
    collect_models,
    visit_value_and_its_immediate_references,
)

if TYPE_CHECKING:
    from ..core.has_props import Setter
    from ..core.query import SelectorType
    from ..document import Document
    from ..document.events import DocumentPatchedEvent
    from ..models.callbacks import (
        Callback as JSEventCallback,
        CustomCode as JSChangeCallback,
    )
    from ..util.callback_manager import PropertyCallback

#-----------------------------------------------------------------------------
# Globals and constants
#-----------------------------------------------------------------------------

__all__ = (
    'Model',
)

#-----------------------------------------------------------------------------
# General API
#-----------------------------------------------------------------------------

#-----------------------------------------------------------------------------
# Dev API
#-----------------------------------------------------------------------------

[docs] @abstract class Model(HasProps, HasDocumentRef, PropertyCallbackManager, EventCallbackManager): ''' Base class for all objects stored in Bokeh |Document| instances. ''' # a canonical order for positional args that can be # used for any functions derived from this class _args = () _extra_kws = {} @classmethod def __init_subclass__(cls): super().__init_subclass__() if cls.__module__.startswith("bokeh.models"): assert "__init__" in cls.__dict__, str(cls) parameters = [x[0] for x in cls.parameters()] cls.__init__.__signature__ = Signature(parameters=parameters) process_example(cls) _id: ID def __new__(cls, *args: Any, id: ID | None = None, **kwargs: Any) -> Model: obj = super().__new__(cls) # Setting 'id' implies deferred initialization, which means properties # will be initialized in a separate step by a deserializer, etc. if id is not None: if args or kwargs: raise ValueError("'id' cannot be used together with property initializers") obj._id = id else: obj._id = make_id() return obj def __init__(self, *args: Any, **kwargs: Any) -> None: if args: raise ValueError("positional arguments are not allowed") if "id" in kwargs: raise ValueError("initializing 'id' is not allowed") super().__init__(**kwargs) default_theme.apply_to_model(self) def __str__(self) -> str: name = self.__class__.__name__ return f"{name}(id={self.id!r}, ...)" __repr__ = __str__
[docs] def destroy(self) -> None: ''' Clean up references to the document and property ''' self._document = None self._temp_document = None self._property_values.clear()
@property def id(self) -> ID: return self._id name: str | None = p.Nullable(p.String, help=""" An arbitrary, user-supplied name for this model. This name can be useful when querying the document to retrieve specific Bokeh models. .. code:: python >>> plot.circle([1,2,3], [4,5,6], name="temp") >>> plot.select(name="temp") [GlyphRenderer(id='399d53f5-73e9-44d9-9527-544b761c7705', ...)] .. note:: No uniqueness guarantees or other conditions are enforced on any names that are provided, nor is the name used directly by Bokeh for any reason. """) tags: list[Any] = p.List(p.AnyRef, help=""" An optional list of arbitrary, user-supplied values to attach to this model. This data can be useful when querying the document to retrieve specific Bokeh models: .. code:: python >>> r = plot.circle([1,2,3], [4,5,6]) >>> r.tags = ["foo", 10] >>> plot.select(tags=['foo', 10]) [GlyphRenderer(id='1de4c3df-a83d-480a-899b-fb263d3d5dd9', ...)] Or simply a convenient way to attach any necessary metadata to a model that can be accessed by ``CustomJS`` callbacks, etc. .. note:: No uniqueness guarantees or other conditions are enforced on any tags that are provided, nor are the tags used directly by Bokeh for any reason. """) js_event_callbacks = p.Dict(p.String, p.List(p.Instance("bokeh.models.callbacks.Callback")), help=""" A mapping of event names to lists of ``CustomJS`` callbacks. Typically, rather then modifying this property directly, callbacks should be added using the ``Model.js_on_event`` method: .. code:: python callback = CustomJS(code="console.log('tap event occurred')") plot.js_on_event('tap', callback) """) js_property_callbacks = p.Dict(p.String, p.List(p.Instance("bokeh.models.callbacks.Callback")), help=""" A mapping of attribute names to lists of ``CustomJS`` callbacks, to be set up on BokehJS side when the document is created. Typically, rather then modifying this property directly, callbacks should be added using the ``Model.js_on_change`` method: .. code:: python callback = CustomJS(code="console.log('stuff')") plot.x_range.js_on_change('start', callback) """) subscribed_events = p.Set(p.String, help=""" Collection of events that are subscribed to by Python callbacks. This is the set of events that will be communicated from BokehJS back to Python for this model. """) syncable: bool = p.Bool(default=True, help=""" Indicates whether this model should be synchronized back to a Bokeh server when updated in a web browser. Setting to ``False`` may be useful to reduce network traffic when dealing with frequently updated objects whose updated values we don't need. .. note:: Setting this property to ``False`` will prevent any ``on_change()`` callbacks on this object from triggering. However, any JS-side callbacks will still work. """) # Properties -------------------------------------------------------------- @property def ref(self) -> Ref: return Ref(id=self._id) # Public methods ----------------------------------------------------------
[docs] @classmethod @without_property_validation def parameters(cls: type[Model]) -> list[Parameter]: ''' Generate Python ``Parameter`` values suitable for functions that are derived from the glyph. Returns: list(Parameter) ''' arg_params = [] no_more_defaults = False for arg in reversed(cls._args): descriptor = cls.lookup(arg) default = descriptor.class_default(cls, no_eval=True) if default is None: no_more_defaults = True # simplify field(x) defaults to just present the column name if isinstance(default, dict) and set(default) == {"field"}: default = default["field"] # make sure built-ins don't hold on to references to actual Models if cls.__module__.startswith("bokeh.models"): assert not isinstance(default, Model) param = Parameter( name=arg, kind=Parameter.POSITIONAL_OR_KEYWORD, # For positional arg properties, default=None means no default. default=Parameter.empty if no_more_defaults else default, ) if default: del default typ = type_link(descriptor.property) arg_params.insert(0, (param, typ, descriptor.__doc__)) # these are not really useful, and should also really be private, just skip them omissions = {'js_event_callbacks', 'js_property_callbacks', 'subscribed_events'} kwarg_params = [] kws = set(cls.properties()) - set(cls._args) - omissions for kw in kws: descriptor = cls.lookup(kw) default = descriptor.class_default(cls, no_eval=True) # simplify field(x) defaults to just present the column name if isinstance(default, dict) and set(default) == {"field"}: default = default["field"] # make sure built-ins don't hold on to references to actual Models if cls.__module__.startswith("bokeh.models"): assert not isinstance(default, Model) param = Parameter( name=kw, kind=Parameter.KEYWORD_ONLY, default=default, ) del default typ = type_link(descriptor.property) kwarg_params.append((param, typ, descriptor.__doc__)) for kw, (typ, doc) in cls._extra_kws.items(): param = Parameter( name=kw, kind=Parameter.KEYWORD_ONLY, ) kwarg_params.append((param, typ, doc)) kwarg_params.sort(key=lambda x: x[0].name) return arg_params + kwarg_params
def js_on_event(self, event: str | type[Event], *callbacks: JSEventCallback) -> None: if isinstance(event, str): event_name = Event.cls_for(event).event_name elif isinstance(event, type) and issubclass(event, Event): event_name = event.event_name else: raise ValueError(f"expected string event name or event class, got {event}") all_callbacks = list(self.js_event_callbacks.get(event_name, [])) for callback in callbacks: if callback not in all_callbacks: all_callbacks.append(callback) self.js_event_callbacks[event_name] = all_callbacks
[docs] def js_on_change(self, event: str, *callbacks: JSChangeCallback) -> None: ''' Attach a :class:`~bokeh.models.CustomJS` callback to an arbitrary BokehJS model event. On the BokehJS side, change events for model properties have the form ``"change:property_name"``. As a convenience, if the event name passed to this method is also the name of a property on the model, then it will be prefixed with ``"change:"`` automatically: .. code:: python # these two are equivalent source.js_on_change('data', callback) source.js_on_change('change:data', callback) However, there are other kinds of events that can be useful to respond to, in addition to property change events. For example to run a callback whenever data is streamed to a ``ColumnDataSource``, use the ``"stream"`` event on the source: .. code:: python source.js_on_change('streaming', callback) ''' if len(callbacks) == 0: raise ValueError("js_on_change takes an event name and one or more callbacks, got only one parameter") # handle any CustomJS callbacks here from bokeh.models.callbacks import CustomCode if not all(isinstance(x, CustomCode) for x in callbacks): raise ValueError("not all callback values are CustomCode instances") descriptor = self.lookup(event, raises=False) if descriptor is not None: event = f"change:{descriptor.name}" old = {k: [cb for cb in cbs] for k, cbs in self.js_property_callbacks.items()} if event not in self.js_property_callbacks: self.js_property_callbacks[event] = [] for callback in callbacks: if callback in self.js_property_callbacks[event]: continue self.js_property_callbacks[event].append(callback) self.trigger('js_property_callbacks', old, self.js_property_callbacks)
[docs] def on_change(self, attr: str, *callbacks: PropertyCallback) -> None: ''' Add a callback on this object to trigger when ``attr`` changes. Args: attr (str) : an attribute name on this object *callbacks (callable) : callback functions to register Returns: None Examples: .. code-block:: python widget.on_change('value', callback1, callback2, ..., callback_n) ''' descriptor = self.lookup(attr) super().on_change(descriptor.name, *callbacks)
[docs] def references(self) -> set[Model]: ''' Returns all ``Models`` that this object has references to. ''' return set(collect_models(self))
[docs] def select(self, selector: SelectorType) -> Iterable[Model]: ''' Query this object and all of its references for objects that match the given selector. Args: selector (JSON-like) : Returns: seq[Model] ''' from ..core.query import find return find(self.references(), selector)
[docs] def select_one(self, selector: SelectorType) -> Model | None: ''' Query this object and all of its references for objects that match the given selector. Raises an error if more than one object is found. Returns single matching object, or None if nothing is found Args: selector (JSON-like) : Returns: Model ''' result = list(self.select(selector)) if len(result) > 1: raise ValueError(f"Found more than one object matching {selector}: {result!r}") if len(result) == 0: return None return result[0]
[docs] def set_select(self, selector: type[Model] | SelectorType, updates: dict[str, Any]) -> None: ''' Update objects that match a given selector with the specified attribute/value updates. Args: selector (JSON-like) : updates (dict) : Returns: None ''' if isclass(selector) and issubclass(selector, Model): selector = dict(type=selector) for obj in self.select(selector): for key, val in updates.items(): setattr(obj, key, val)
[docs] def to_serializable(self, serializer: Serializer) -> ObjectRefRep: serializer.add_ref(self, self.ref) super_rep = super().to_serializable(serializer) rep = ObjectRefRep( type="object", name=super_rep["name"], id=self.id, ) attributes = super_rep.get("attributes") if attributes is not None: rep["attributes"] = attributes return rep
[docs] def trigger(self, attr: str, old: Any, new: Any, hint: DocumentPatchedEvent | None = None, setter: Setter | None = None) -> None: ''' ''' # The explicit assumption here is that hinted events do not need to # go through all the same invalidation steps. Currently this is the # case for ColumnsStreamedEvent and ColumnsPatchedEvent. However, # this may need to be further refined in the future, if the # assumption does not hold for future hinted events (e.g. the hint # could specify explicitly whether to do normal invalidation or not) if hint is None: dirty_count = 0 def mark_dirty(_: HasProps): nonlocal dirty_count dirty_count += 1 if self._document is not None: visit_value_and_its_immediate_references(new, mark_dirty) visit_value_and_its_immediate_references(old, mark_dirty) if dirty_count > 0: self.document.models.invalidate() # chain up to invoke callbacks descriptor = self.lookup(attr) super().trigger(descriptor.name, old, new, hint=hint, setter=setter)
def _attach_document(self, doc: Document) -> None: ''' Attach a model to a Bokeh |Document|. This private interface should only ever called by the Document implementation to set the private ._document field properly ''' if self.document is doc: # nothing to do return if self.document is not None: raise RuntimeError(f"Models must be owned by only a single document, {self!r} is already in a doc") doc.theme.apply_to_model(self) self.document = doc self._update_event_callbacks() @classmethod def _clear_extensions(cls) -> None: _default_resolver.clear_extensions() def _detach_document(self) -> None: ''' Detach a model from a Bokeh |Document|. This private interface should only ever called by the Document implementation to unset the private ._document field properly ''' self.document = None default_theme.apply_to_model(self) def _repr_html_(self) -> str: return html_repr(self) def _sphinx_height_hint(self) -> int|None: return None
#----------------------------------------------------------------------------- # Private API #----------------------------------------------------------------------------- #----------------------------------------------------------------------------- # Code #-----------------------------------------------------------------------------