#----------------------------------------------------------------------------- # Copyright (c) 2012 - 2019, 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 absolute_import, division, print_function, unicode_literals import logging log = logging.getLogger(__name__) #----------------------------------------------------------------------------- # Imports #----------------------------------------------------------------------------- # Standard library imports from json import loads from operator import itemgetter # External imports from six import iteritems, string_types # Bokeh imports from .core.json_encoder import serialize_json from .core.properties import Any, Dict, Instance, List, String from .core.has_props import HasProps, MetaHasProps from .core.query import find from .events import Event from .themes import default as default_theme from .util.callback_manager import PropertyCallbackManager, EventCallbackManager from .util.future import with_metaclass from .util.serialization import make_id #----------------------------------------------------------------------------- # Globals and constants #----------------------------------------------------------------------------- __all__ = ( 'collect_models', 'get_class', 'Model', ) #----------------------------------------------------------------------------- # General API #----------------------------------------------------------------------------- #----------------------------------------------------------------------------- # Dev API #----------------------------------------------------------------------------- def collect_filtered_models(discard, *input_values): ''' Collect a duplicate-free list of all other Bokeh models referred to by this model, or by any of its references, etc, unless filtered-out by the provided callable. Iterate over ``input_values`` and descend through their structure collecting all nested ``Models`` on the go. Args: *discard (Callable[[Model], bool]) a callable which accepts a *Model* instance as its single argument and returns a boolean stating whether to discard the instance. The latter means that the instance will not be added to collected models nor will its references be explored. *input_values (Model) Bokeh models to collect other models from Returns: None ''' ids = set([]) collected = [] queued = [] def queue_one(obj): if obj.id not in ids and not (callable(discard) and discard(obj)): queued.append(obj) for value in input_values: _visit_value_and_its_immediate_references(value, queue_one) while queued: obj = queued.pop(0) if obj.id not in ids: ids.add(obj.id) collected.append(obj) _visit_immediate_value_references(obj, queue_one) return collected [docs]def collect_models(*input_values): ''' Collect a duplicate-free list of all other Bokeh models referred to by this model, or by any of its references, etc. Iterate over ``input_values`` and descend through their structure collecting all nested ``Models`` on the go. The resulting list is duplicate-free based on objects' identifiers. Args: *input_values (Model) Bokeh models to collect other models from Returns: list[Model] : all models reachable from this one. ''' return collect_filtered_models(None, *input_values) [docs]def get_class(view_model_name): ''' Look up a Bokeh model class, given its view model name. Args: view_model_name (str) : A view model name for a Bokeh model to look up Returns: Model: the model class corresponding to ``view_model_name`` Raises: KeyError, if the model cannot be found Example: .. code-block:: python >>> from bokeh.model import get_class >>> get_class("Range1d") <class 'bokeh.models.ranges.Range1d'> ''' # in order to look up from the model catalog that MetaModel maintains, it # has to be creates first. These imports ensure that all built-in Bokeh # models are represented in the catalog. from . import models; models from .plotting import Figure; Figure d = MetaModel.model_class_reverse_map if view_model_name in d: return d[view_model_name] else: raise KeyError("View model name '%s' not found" % view_model_name) #----------------------------------------------------------------------------- # Dev API #----------------------------------------------------------------------------- class MetaModel(MetaHasProps): ''' Specialize the construction of |Model| classes. This class is a `metaclass`_ for |Model| that is responsible for automatically cataloging all Bokeh models that get defined, so that the serialization machinery between Bokeh and BokehJS can function properly. .. note:: It is worth pointing out explicitly that this relies on the rules for Metaclass inheritance in Python. Bokeh works by replicating Python model objects (e.g. plots, ranges, data sources, which are all |HasProps| subclasses) into BokehJS. In the case of using a Bokeh server, the Bokeh model objects can also be synchronized bidirectionally. This is accomplished by serializing the models to and from a JSON format, that includes the name of the model type as part of the payload, as well as a unique ID, and all the attributes: .. code-block:: javascript { type: "Plot", id: 100032, attributes: { ... } } Typically the type name is inferred automatically from the Python class name, and is set as the ``__view_model__`` class attribute on the Model class that is create. But it is also possible to override this value explicitly: .. code-block:: python class Foo(Model): pass class Bar(Model): __view_model__ == "Quux" This metaclass will raise an error if two Bokeh models are created that attempt to have the same view model name. The only exception made is if one of the models has a custom ``__implementation__`` in its class definition. This metaclass also handles subtype relationships between Bokeh models. Occasionally it may be necessary for multiple class types on the Python side to resolve to the same type on the BokehJS side. This is called subtyping, and is expressed through a ``__subtype__`` class attribute on a model: .. code-block:: python class Foo(Model): pass class Bar(Foo): __view_model__ = "Foo" __subtype__ = "Bar" In this case, python instances of ``Foo`` and ``Bar`` will both resolve to ``Foo`` models in BokehJS. In the context of a Bokeh server application, the original python types will be faithfully round-tripped. (Without the ``__subtype__`` specified, the above code would raise an error due to duplicate view model names.) .. _metaclass: https://docs.python.org/3/reference/datamodel.html#metaclasses ''' model_class_reverse_map = {} def __new__(meta_cls, class_name, bases, class_dict): ''' Raises: Warning ''' # use an explicitly provided view model name if there is one if "__view_model__" not in class_dict: class_dict["__view_model__"] = class_name if "__view_module__" not in class_dict: class_dict["__view_module__"] = class_dict["__module__"] module = class_dict["__view_module__"] model = class_dict.get("__subtype__", class_dict["__view_model__"]) impl = class_dict.get("__implementation__", None) head = module.split(".")[0] if head == "bokeh" or head == "__main__" or impl is not None: qualified = model else: qualified = module + "." + model class_dict["__qualified_model__"] = qualified # call the parent metaclass to create the new model type newcls = super(MetaModel, meta_cls).__new__(meta_cls, class_name, bases, class_dict) # update the mapping of view model names to classes, checking for any duplicates # and handling any subtype relationships or custom implementations if qualified in MetaModel.model_class_reverse_map and not hasattr(newcls, "__implementation__"): raise Warning("Duplicate qualified model declaration of '%s'. Previous definition: %s" % ( qualified, MetaModel.model_class_reverse_map[qualified])) MetaModel.model_class_reverse_map[qualified] = newcls return newcls _HTML_REPR = """ <script> (function() { var expanded = false; var ellipsis = document.getElementById("%(ellipsis_id)s"); ellipsis.addEventListener("click", function() { var rows = document.getElementsByClassName("%(cls_name)s"); for (var i = 0; i < rows.length; i++) { var el = rows[i]; el.style.display = expanded ? "none" : "table-row"; } ellipsis.innerHTML = expanded ? "…)" : "‹‹‹"; expanded = !expanded; }); })(); </script> """ [docs]class Model(with_metaclass(MetaModel, HasProps, PropertyCallbackManager, EventCallbackManager)): ''' Base class for all objects stored in Bokeh |Document| instances. ''' def __new__(cls, *args, **kwargs): obj = super(Model, cls).__new__(cls) obj._id = kwargs.pop("id", make_id()) obj._document = None obj._temp_document = None return obj def __init__(self, **kwargs): # "id" is popped from **kw in __new__, so in an ideal world I don't # think it should be here too. But Python does this, so it is: # # class Foo(object): # def __new__(cls, *args, **kw): # obj = super(Foo, cls).__new__(cls) # obj.bar = kw.pop("bar", 111) # print("__new__ :", id(kw), kw) # return obj # def __init__(self, **kw): # print("__init__ :", id(kw), kw) # # >>> f = Foo(bar=10) # __new__ : 4405522296 {} # __init__ : 4405522296 {'bar': 10} kwargs.pop("id", None) super(Model, self).__init__(**kwargs) default_theme.apply_to_model(self) def __str__(self): return "%s(id=%r, ...)" % (self.__class__.__name__, getattr(self, "id", None)) __repr__ = __str__ @property def id(self): return self._id name = 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, 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 = Dict(String, List(Instance("bokeh.models.callbacks.CustomJS")), 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) """) subscribed_events = List(String, help=""" List 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. """) js_property_callbacks = Dict(String, List(Instance("bokeh.models.callbacks.CustomJS")), 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) """) # Properties -------------------------------------------------------------- @property def document(self): ''' The |Document| this model is attached to (can be ``None``) ''' if self._temp_document is not None: return self._temp_document return self._document @property def ref(self): ''' A Bokeh protocol "reference" to this model, i.e. a dict of the form: .. code-block:: python { 'type' : << view model name >> 'id' : << unique model id >> } Additionally there may be a `subtype` field if this model is a subtype. ''' this = { 'type': self.__qualified_model__, 'id' : self.id, } if "__subtype__" in self.__class__.__dict__: # XXX: remove __subtype__ and this garbage at 2.0 parts = this["type"].split(".") parts[-1] = self.__view_model__ this["type"] = ".".join(parts) this["subtype"] = self.__subtype__ return this # Public methods ---------------------------------------------------------- [docs] def js_on_event(self, event, *callbacks): if not isinstance(event, string_types) and issubclass(event, Event): event = event.event_name if event not in self.js_event_callbacks: self.js_event_callbacks[event] = [] for callback in callbacks: if callback in self.js_event_callbacks[event]: continue self.js_event_callbacks[event].append(callback) [docs] def js_link(self, attr, other, other_attr): ''' Link two Bokeh model properties using JavaScript. This is a convenience method that simplifies adding a CustomJS callback to update one Bokeh model property whenever another changes value. Args: attr (str) : The name of a Bokeh property on this model other (Model): A Bokeh model to link to self.attr other_attr (str) : The property on ``other`` to link together Added in version 1.1 Raises: ValueError Examples: This code with ``js_link``: .. code :: python select.js_link('value', plot, 'sizing_mode') is equivalent to the following: .. code:: python from bokeh.models import CustomJS select.js_on_change('value', CustomJS(args=dict(other=plot), code="other.sizing_mode = this.value" ) ) ''' if attr not in self.properties(): raise ValueError("%r is not a property of self (%r)" % (attr, self)) if not isinstance(other, Model): raise ValueError("'other' is not a Bokeh model: %r" % other) if other_attr not in other.properties(): raise ValueError("%r is not a property of other (%r)" % (other_attr, other)) from bokeh.models.callbacks import CustomJS cb = CustomJS(args=dict(other=other), code="other.%s = this.%s" % (other_attr, attr)) self.js_on_change(attr, cb) [docs] def js_on_change(self, event, *callbacks): ''' Attach a ``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 CustomJS if not all(isinstance(x, CustomJS) for x in callbacks): raise ValueError("not all callback values are CustomJS instances") if event in self.properties(): event = "change:%s" % event 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 layout(self, side, plot): ''' ''' try: return self in getattr(plot, side) except: return [] [docs] def on_change(self, attr, *callbacks): ''' 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 Example: .. code-block:: python widget.on_change('value', callback1, callback2, ..., callback_n) ''' if attr not in self.properties(): raise ValueError("attempted to add a callback on nonexistent %s.%s property" % (self.__class__.__name__, attr)) super(Model, self).on_change(attr, *callbacks) [docs] def references(self): ''' Returns all ``Models`` that this object has references to. ''' return set(collect_models(self)) [docs] def select(self, selector): ''' Query this object and all of its references for objects that match the given selector. Args: selector (JSON-like) : Returns: seq[Model] ''' return find(self.references(), selector) [docs] def select_one(self, selector): ''' 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("Found more than one object matching %s: %r" % (selector, result)) if len(result) == 0: return None return result[0] [docs] def set_select(self, selector, updates): ''' Update objects that match a given selector with the specified attribute/value updates. Args: selector (JSON-like) : updates (dict) : Returns: None ''' for obj in self.select(selector): for key, val in updates.items(): setattr(obj, key, val) [docs] def to_json(self, include_defaults): ''' Returns a dictionary of the attributes of this object, containing only "JSON types" (string, number, boolean, none, dict, list). References to other objects are serialized as "refs" (just the object ID and type info), so the deserializer will need to separately have the full attributes of those other objects. There's no corresponding ``from_json()`` because to deserialize an object is normally done in the context of a Document (since the Document can resolve references). For most purposes it's best to serialize and deserialize entire documents. Args: include_defaults (bool) : whether to include attributes that haven't been changed from the default ''' return loads(self.to_json_string(include_defaults=include_defaults)) [docs] def to_json_string(self, include_defaults): ''' Returns a JSON string encoding the attributes of this object. References to other objects are serialized as references (just the object ID and type info), so the deserializer will need to separately have the full attributes of those other objects. There's no corresponding ``from_json_string()`` because to deserialize an object is normally done in the context of a Document (since the Document can resolve references). For most purposes it's best to serialize and deserialize entire documents. Args: include_defaults (bool) : whether to include attributes that haven't been changed from the default ''' json_like = self._to_json_like(include_defaults=include_defaults) json_like['id'] = self.id # serialize_json "fixes" the JSON from _to_json_like by converting # all types into plain JSON types # (it converts Model into refs, # for example). return serialize_json(json_like) [docs] def trigger(self, attr, old, new, hint=None, setter=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(obj): 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._invalidate_all_models() # chain up to invoke callbacks super(Model, self).trigger(attr, old, new, hint=hint, setter=setter) def _attach_document(self, doc): ''' 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 not None and self._document is not doc: raise RuntimeError("Models must be owned by only a single document, %r is already in a doc" % (self)) doc.theme.apply_to_model(self) self._document = doc self._update_event_callbacks() @staticmethod def _clear_extensions(): MetaModel.model_class_reverse_map = { k:v for k,v in MetaModel.model_class_reverse_map.items() if getattr(v, "__implementation__", None) is None } def _detach_document(self): ''' 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 _to_json_like(self, include_defaults): ''' Returns a dictionary of the attributes of this object, in a layout corresponding to what BokehJS expects at unmarshalling time. This method does not convert "Bokeh types" into "plain JSON types," for example each child Model will still be a Model, rather than turning into a reference, numpy isn't handled, etc. That's what "json like" means. This method should be considered "private" or "protected", for use internal to Bokeh; use ``to_json()`` instead because it gives you only plain JSON-compatible types. Args: include_defaults (bool) : whether to include attributes that haven't been changed from the default. ''' all_attrs = self.properties_with_values(include_defaults=include_defaults) # If __subtype__ is defined, then this model may introduce properties # that don't exist on __view_model__ in bokehjs. Don't serialize such # properties. subtype = getattr(self.__class__, "__subtype__", None) if subtype is not None and subtype != self.__class__.__view_model__: attrs = {} for attr, value in all_attrs.items(): if attr in self.__class__.__dict__: continue else: attrs[attr] = value else: attrs = all_attrs for (k, v) in attrs.items(): # we can't serialize Infinity, we send it as None and # the other side has to fix it up. This transformation # can't be in our json_encoder because the json # module checks for inf before it calls the custom # encoder. if isinstance(v, float) and v == float('inf'): attrs[k] = None return attrs def _repr_html_(self): ''' ''' module = self.__class__.__module__ name = self.__class__.__name__ _id = getattr(self, "_id", None) cls_name = make_id() def row(c): return '<div style="display: table-row;">' + c + '</div>' def hidden_row(c): return '<div class="%s" style="display: none;">%s</div>' % (cls_name, c) def cell(c): return '<div style="display: table-cell;">' + c + '</div>' html = '' html += '<div style="display: table;">' ellipsis_id = make_id() ellipsis = '<span id="%s" style="cursor: pointer;">…)</span>' % ellipsis_id prefix = cell('<b title="%s.%s">%s</b>(' % (module, name, name)) html += row(prefix + cell('id' + ' = ' + repr(_id) + ', ' + ellipsis)) props = self.properties_with_values().items() sorted_props = sorted(props, key=itemgetter(0)) all_props = sorted_props for i, (prop, value) in enumerate(all_props): end = ')' if i == len(all_props)-1 else ',' html += hidden_row(cell("") + cell(prop + ' = ' + repr(value) + end)) html += '</div>' html += _HTML_REPR % dict(ellipsis_id=ellipsis_id, cls_name=cls_name) return html #----------------------------------------------------------------------------- # Private API #----------------------------------------------------------------------------- def _visit_immediate_value_references(value, visitor): ''' Visit all references to another Model without recursing into any of the child Model; may visit the same Model more than once if it's referenced more than once. Does not visit the passed-in value. ''' if isinstance(value, HasProps): for attr in value.properties_with_refs(): child = getattr(value, attr) _visit_value_and_its_immediate_references(child, visitor) else: _visit_value_and_its_immediate_references(value, visitor) _common_types = {int, float, str} def _visit_value_and_its_immediate_references(obj, visitor): ''' Recurse down Models, HasProps, and Python containers The ordering in this function is to optimize performance. We check the most comomn types (int, float, str) first so that we can quickly return in the common case. We avoid isinstance and issubclass checks in a couple places with `type` checks because isinstance checks can be slow. ''' typ = type(obj) if typ in _common_types: # short circuit on common base types return if typ is list or issubclass(typ, (list, tuple)): # check common containers for item in obj: _visit_value_and_its_immediate_references(item, visitor) elif issubclass(typ, dict): for key, value in iteritems(obj): _visit_value_and_its_immediate_references(key, visitor) _visit_value_and_its_immediate_references(value, visitor) elif issubclass(typ, HasProps): if issubclass(typ, Model): visitor(obj) else: # this isn't a Model, so recurse into it _visit_immediate_value_references(obj, visitor) #----------------------------------------------------------------------------- # Code #-----------------------------------------------------------------------------