bokeh.models.expressions

Represent array expressions to be computed on the client (browser) side by BokehJS.

Expression models are useful as DataSpec values when it is desired that the array values be computed in the browser:

p.circle(x={'expr': some_expression}, ...)

or using the expr convenience function:

from bokeh.core.properties import expr

p.circle(x=expr(some_expression), ...)

In this case, the values of the x coordinates will be computed in the browser by the JavaScript implementation of some_expression using a ColumnDataSource as input.

class CumSum(*args, **kwargs)[source]

Bases: bokeh.models.expressions.Expression

An expression for generating arrays by cumulatively summing a single column from a ColumnDataSource.

field

property type: String

The name of a ColumnDataSource column to cumulatively sum for new values.

include_zero

property type: Bool

Whether to include zero at the start of the result. Note that the length of the result is always the same as the input column. Therefore if this property is True, then the last value of the column will not be included in the sum.

source = ColumnDataSource(data=dict(foo=[1, 2, 3, 4]))

CumSum(field='foo')
# -> [1, 3, 6, 10]

CumSum(field='foo', include_zero=True)
# -> [0, 1, 3, 6]
js_event_callbacks

property type: Dict ( String , List ( Instance ( CustomJS ) ) )

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:

callback = CustomJS(code="console.log('tap event occurred')")
plot.js_on_event('tap', callback)
js_property_callbacks

property type: Dict ( String , List ( Instance ( CustomJS ) ) )

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:

callback = CustomJS(code="console.log('stuff')")
plot.x_range.js_on_change('start', callback)
name

property type: String

An arbitrary, user-supplied name for this model.

This name can be useful when querying the document to retrieve specific Bokeh models.

>>> 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.

subscribed_events

property type: List ( String )

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.

tags

property type: List ( Any )

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:

>>> 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.

apply_theme(property_values)

Apply a set of theme values which will be used rather than defaults, but will not override application-set values.

The passed-in dictionary may be kept around as-is and shared with other instances to save memory (so neither the caller nor the HasProps instance should modify it).

Parameters

property_values (dict) – theme values to use in place of defaults

Returns

None

classmethod dataspecs()

Collect the names of all DataSpec properties on this class.

This method always traverses the class hierarchy and includes properties defined on any parent classes.

Returns

names of DataSpec properties

Return type

set[str]

classmethod dataspecs_with_props()

Collect a dict mapping the names of all DataSpec properties on this class to the associated properties.

This method always traverses the class hierarchy and includes properties defined on any parent classes.

Returns

mapping of names and DataSpec properties

Return type

dict[str, DataSpec]

equals(other)

Structural equality of models.

Parameters

other (HasProps) – the other instance to compare to

Returns

True, if properties are structurally equal, otherwise False

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.

Parameters
  • 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

  • attr_selector (Union[int, str]) – The index to link an item in a subscriptable attr

Added in version 1.1

Raises

ValueError

Examples

This code with js_link:

select.js_link('value', plot, 'sizing_mode')

is equivalent to the following:

from bokeh.models import CustomJS
select.js_on_change('value',
    CustomJS(args=dict(other=plot),
             code="other.sizing_mode = this.value"
    )
)

Additionally, to use attr_selector to attach the left side of a range slider to a plot’s x_range:

range_slider.js_link('value', plot.x_range, 'start', attr_selector=0)

which is equivalent to:

from bokeh.models import CustomJS
range_slider.js_on_change('value',
    CustomJS(args=dict(other=plot.x_range),
             code="other.start = this.value[0]"
    )
)
js_on_change(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:

# 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:

source.js_on_change('streaming', callback)
layout(side, plot)
classmethod lookup(name)

Find the PropertyDescriptor for a Bokeh property on a class, given the property name.

Parameters

name (str) – name of the property to search for

Returns

descriptor for property named name

Return type

PropertyDescriptor

on_change(attr, *callbacks)

Add a callback on this object to trigger when attr changes.

Parameters
  • attr (str) – an attribute name on this object

  • *callbacks (callable) – callback functions to register

Returns

None

Example:

widget.on_change('value', callback1, callback2, ..., callback_n)
classmethod properties(with_bases=True)

Collect the names of properties on this class.

This method optionally traverses the class hierarchy and includes properties defined on any parent classes.

Parameters

with_bases (bool, optional) – Whether to include properties defined on parent classes in the results. (default: True)

Returns

property names

Return type

set[str]

classmethod properties_containers()

Collect the names of all container properties on this class.

This method always traverses the class hierarchy and includes properties defined on any parent classes.

Returns

names of container properties

Return type

set[str]

classmethod properties_with_refs()

Collect the names of all properties on this class that also have references.

This method always traverses the class hierarchy and includes properties defined on any parent classes.

Returns

names of properties that have references

Return type

set[str]

properties_with_values(include_defaults: bool = True) → Dict[str, Any]

Collect a dict mapping property names to their values.

This method always traverses the class hierarchy and includes properties defined on any parent classes.

Non-serializable properties are skipped and property values are in “serialized” format which may be slightly different from the values you would normally read from the properties; the intent of this method is to return the information needed to losslessly reconstitute the object instance.

Parameters

include_defaults (bool, optional) – Whether to include properties that haven’t been explicitly set since the object was created. (default: True)

Returns

mapping from property names to their values

Return type

dict

query_properties_with_values(query, include_defaults=True)

Query the properties values of HasProps instances with a predicate.

Parameters
  • query (callable) – A callable that accepts property descriptors and returns True or False

  • include_defaults (bool, optional) – Whether to include properties that have not been explicitly set by a user (default: True)

Returns

mapping of property names and values for matching properties

Return type

dict

references()

Returns all Models that this object has references to.

remove_on_change(attr, *callbacks)

Remove a callback from this object

select(selector)

Query this object and all of its references for objects that match the given selector.

Parameters

selector (JSON-like) –

Returns

seq[Model]

select_one(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 :param selector: :type selector: JSON-like

Returns

Model

set_from_json(name, json, models=None, setter=None)

Set a property value on this object from JSON.

Parameters
  • name – (str) : name of the attribute to set

  • json – (JSON-value) : value to set to the attribute to

  • models (dict or None, optional) –

    Mapping of model ids to models (default: None)

    This is needed in cases where the attributes to update also have values that have references.

  • setter (ClientSession or ServerSession or None, optional) –

    This is used to prevent “boomerang” updates to Bokeh apps.

    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.

Returns

None

set_select(selector, updates)

Update objects that match a given selector with the specified attribute/value updates.

Parameters
  • selector (JSON-like) –

  • updates (dict) –

Returns

None

themed_values()

Get any theme-provided overrides.

Results are returned as a dict from property name to value, or None if no theme overrides any values for this instance.

Returns

dict or None

to_json(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.

Parameters

include_defaults (bool) – whether to include attributes that haven’t been changed from the default

to_json_string(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.

Parameters

include_defaults (bool) – whether to include attributes that haven’t been changed from the default

trigger(attr, old, new, hint=None, setter=None)
unapply_theme()

Remove any themed values and restore defaults.

Returns

None

update(**kwargs)

Updates the object’s properties from the given keyword arguments.

Returns

None

Examples

The following are equivalent:

from bokeh.models import Range1d

r = Range1d

# set properties individually:
r.start = 10
r.end = 20

# update properties together:
r.update(start=10, end=20)
update_from_json(json_attributes, models=None, setter=None)

Updates the object’s properties from a JSON attributes dictionary.

Parameters
  • json_attributes – (JSON-dict) : attributes and values to update

  • models (dict or None, optional) –

    Mapping of model ids to models (default: None)

    This is needed in cases where the attributes to update also have values that have references.

  • setter (ClientSession or ServerSession or None, optional) –

    This is used to prevent “boomerang” updates to Bokeh apps.

    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.

Returns

None

property document

The Document this model is attached to (can be None)

property struct

A Bokeh protocol “structure” of this model, i.e. a dict of the form:

{
    'type' : << view model name >>
    'id'   : << unique model id >>
}

Additionally there may be a subtype field if this model is a subtype.

JSON Prototype
{
  "field": null,
  "id": "10094",
  "include_zero": false,
  "js_event_callbacks": {},
  "js_property_callbacks": {},
  "name": null,
  "subscribed_events": [],
  "tags": []
}
class Expression(*args, **kwargs)[source]

Bases: bokeh.model.Model

Base class for Expression models that represent a computation to be carried out on the client-side.

JavaScript implementations should implement the following methods:

Note

If you wish for results to be cached per source and updated only if the source changes, implement _v_compute: (source) instead.

Note

This is an abstract base class used to help organize the hierarchy of Bokeh model types. It is not useful to instantiate on its own.

js_event_callbacks

property type: Dict ( String , List ( Instance ( CustomJS ) ) )

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:

callback = CustomJS(code="console.log('tap event occurred')")
plot.js_on_event('tap', callback)
js_property_callbacks

property type: Dict ( String , List ( Instance ( CustomJS ) ) )

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:

callback = CustomJS(code="console.log('stuff')")
plot.x_range.js_on_change('start', callback)
name

property type: String

An arbitrary, user-supplied name for this model.

This name can be useful when querying the document to retrieve specific Bokeh models.

>>> 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.

subscribed_events

property type: List ( String )

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.

tags

property type: List ( Any )

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:

>>> 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.

apply_theme(property_values)

Apply a set of theme values which will be used rather than defaults, but will not override application-set values.

The passed-in dictionary may be kept around as-is and shared with other instances to save memory (so neither the caller nor the HasProps instance should modify it).

Parameters

property_values (dict) – theme values to use in place of defaults

Returns

None

classmethod dataspecs()

Collect the names of all DataSpec properties on this class.

This method always traverses the class hierarchy and includes properties defined on any parent classes.

Returns

names of DataSpec properties

Return type

set[str]

classmethod dataspecs_with_props()

Collect a dict mapping the names of all DataSpec properties on this class to the associated properties.

This method always traverses the class hierarchy and includes properties defined on any parent classes.

Returns

mapping of names and DataSpec properties

Return type

dict[str, DataSpec]

equals(other)

Structural equality of models.

Parameters

other (HasProps) – the other instance to compare to

Returns

True, if properties are structurally equal, otherwise False

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.

Parameters
  • 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

  • attr_selector (Union[int, str]) – The index to link an item in a subscriptable attr

Added in version 1.1

Raises

ValueError

Examples

This code with js_link:

select.js_link('value', plot, 'sizing_mode')

is equivalent to the following:

from bokeh.models import CustomJS
select.js_on_change('value',
    CustomJS(args=dict(other=plot),
             code="other.sizing_mode = this.value"
    )
)

Additionally, to use attr_selector to attach the left side of a range slider to a plot’s x_range:

range_slider.js_link('value', plot.x_range, 'start', attr_selector=0)

which is equivalent to:

from bokeh.models import CustomJS
range_slider.js_on_change('value',
    CustomJS(args=dict(other=plot.x_range),
             code="other.start = this.value[0]"
    )
)
js_on_change(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:

# 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:

source.js_on_change('streaming', callback)
layout(side, plot)
classmethod lookup(name)

Find the PropertyDescriptor for a Bokeh property on a class, given the property name.

Parameters

name (str) – name of the property to search for

Returns

descriptor for property named name

Return type

PropertyDescriptor

on_change(attr, *callbacks)

Add a callback on this object to trigger when attr changes.

Parameters
  • attr (str) – an attribute name on this object

  • *callbacks (callable) – callback functions to register

Returns

None

Example:

widget.on_change('value', callback1, callback2, ..., callback_n)
classmethod properties(with_bases=True)

Collect the names of properties on this class.

This method optionally traverses the class hierarchy and includes properties defined on any parent classes.

Parameters

with_bases (bool, optional) – Whether to include properties defined on parent classes in the results. (default: True)

Returns

property names

Return type

set[str]

classmethod properties_containers()

Collect the names of all container properties on this class.

This method always traverses the class hierarchy and includes properties defined on any parent classes.

Returns

names of container properties

Return type

set[str]

classmethod properties_with_refs()

Collect the names of all properties on this class that also have references.

This method always traverses the class hierarchy and includes properties defined on any parent classes.

Returns

names of properties that have references

Return type

set[str]

properties_with_values(include_defaults: bool = True) → Dict[str, Any]

Collect a dict mapping property names to their values.

This method always traverses the class hierarchy and includes properties defined on any parent classes.

Non-serializable properties are skipped and property values are in “serialized” format which may be slightly different from the values you would normally read from the properties; the intent of this method is to return the information needed to losslessly reconstitute the object instance.

Parameters

include_defaults (bool, optional) – Whether to include properties that haven’t been explicitly set since the object was created. (default: True)

Returns

mapping from property names to their values

Return type

dict

query_properties_with_values(query, include_defaults=True)

Query the properties values of HasProps instances with a predicate.

Parameters
  • query (callable) – A callable that accepts property descriptors and returns True or False

  • include_defaults (bool, optional) – Whether to include properties that have not been explicitly set by a user (default: True)

Returns

mapping of property names and values for matching properties

Return type

dict

references()

Returns all Models that this object has references to.

remove_on_change(attr, *callbacks)

Remove a callback from this object

select(selector)

Query this object and all of its references for objects that match the given selector.

Parameters

selector (JSON-like) –

Returns

seq[Model]

select_one(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 :param selector: :type selector: JSON-like

Returns

Model

set_from_json(name, json, models=None, setter=None)

Set a property value on this object from JSON.

Parameters
  • name – (str) : name of the attribute to set

  • json – (JSON-value) : value to set to the attribute to

  • models (dict or None, optional) –

    Mapping of model ids to models (default: None)

    This is needed in cases where the attributes to update also have values that have references.

  • setter (ClientSession or ServerSession or None, optional) –

    This is used to prevent “boomerang” updates to Bokeh apps.

    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.

Returns

None

set_select(selector, updates)

Update objects that match a given selector with the specified attribute/value updates.

Parameters
  • selector (JSON-like) –

  • updates (dict) –

Returns

None

themed_values()

Get any theme-provided overrides.

Results are returned as a dict from property name to value, or None if no theme overrides any values for this instance.

Returns

dict or None

to_json(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.

Parameters

include_defaults (bool) – whether to include attributes that haven’t been changed from the default

to_json_string(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.

Parameters

include_defaults (bool) – whether to include attributes that haven’t been changed from the default

trigger(attr, old, new, hint=None, setter=None)
unapply_theme()

Remove any themed values and restore defaults.

Returns

None

update(**kwargs)

Updates the object’s properties from the given keyword arguments.

Returns

None

Examples

The following are equivalent:

from bokeh.models import Range1d

r = Range1d

# set properties individually:
r.start = 10
r.end = 20

# update properties together:
r.update(start=10, end=20)
update_from_json(json_attributes, models=None, setter=None)

Updates the object’s properties from a JSON attributes dictionary.

Parameters
  • json_attributes – (JSON-dict) : attributes and values to update

  • models (dict or None, optional) –

    Mapping of model ids to models (default: None)

    This is needed in cases where the attributes to update also have values that have references.

  • setter (ClientSession or ServerSession or None, optional) –

    This is used to prevent “boomerang” updates to Bokeh apps.

    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.

Returns

None

property document

The Document this model is attached to (can be None)

property struct

A Bokeh protocol “structure” of this model, i.e. a dict of the form:

{
    'type' : << view model name >>
    'id'   : << unique model id >>
}

Additionally there may be a subtype field if this model is a subtype.

JSON Prototype
{
  "id": "10102",
  "js_event_callbacks": {},
  "js_property_callbacks": {},
  "name": null,
  "subscribed_events": [],
  "tags": []
}
class Stack(*args, **kwargs)[source]

Bases: bokeh.models.expressions.Expression

An expression for generating arrays by summing different columns from a ColumnDataSource.

This expression is useful for implementing stacked bar charts at a low level.

fields

property type: Seq ( String )

A sequence of fields from a ColumnDataSource to sum (elementwise). For example:

Stack(fields=['sales', 'marketing'])

Will compute an array of values (in the browser) by adding the elements of the 'sales' and 'marketing' columns of a data source.

js_event_callbacks

property type: Dict ( String , List ( Instance ( CustomJS ) ) )

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:

callback = CustomJS(code="console.log('tap event occurred')")
plot.js_on_event('tap', callback)
js_property_callbacks

property type: Dict ( String , List ( Instance ( CustomJS ) ) )

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:

callback = CustomJS(code="console.log('stuff')")
plot.x_range.js_on_change('start', callback)
name

property type: String

An arbitrary, user-supplied name for this model.

This name can be useful when querying the document to retrieve specific Bokeh models.

>>> 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.

subscribed_events

property type: List ( String )

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.

tags

property type: List ( Any )

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:

>>> 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.

apply_theme(property_values)

Apply a set of theme values which will be used rather than defaults, but will not override application-set values.

The passed-in dictionary may be kept around as-is and shared with other instances to save memory (so neither the caller nor the HasProps instance should modify it).

Parameters

property_values (dict) – theme values to use in place of defaults

Returns

None

classmethod dataspecs()

Collect the names of all DataSpec properties on this class.

This method always traverses the class hierarchy and includes properties defined on any parent classes.

Returns

names of DataSpec properties

Return type

set[str]

classmethod dataspecs_with_props()

Collect a dict mapping the names of all DataSpec properties on this class to the associated properties.

This method always traverses the class hierarchy and includes properties defined on any parent classes.

Returns

mapping of names and DataSpec properties

Return type

dict[str, DataSpec]

equals(other)

Structural equality of models.

Parameters

other (HasProps) – the other instance to compare to

Returns

True, if properties are structurally equal, otherwise False

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.

Parameters
  • 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

  • attr_selector (Union[int, str]) – The index to link an item in a subscriptable attr

Added in version 1.1

Raises

ValueError

Examples

This code with js_link:

select.js_link('value', plot, 'sizing_mode')

is equivalent to the following:

from bokeh.models import CustomJS
select.js_on_change('value',
    CustomJS(args=dict(other=plot),
             code="other.sizing_mode = this.value"
    )
)

Additionally, to use attr_selector to attach the left side of a range slider to a plot’s x_range:

range_slider.js_link('value', plot.x_range, 'start', attr_selector=0)

which is equivalent to:

from bokeh.models import CustomJS
range_slider.js_on_change('value',
    CustomJS(args=dict(other=plot.x_range),
             code="other.start = this.value[0]"
    )
)
js_on_change(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:

# 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:

source.js_on_change('streaming', callback)
layout(side, plot)
classmethod lookup(name)

Find the PropertyDescriptor for a Bokeh property on a class, given the property name.

Parameters

name (str) – name of the property to search for

Returns

descriptor for property named name

Return type

PropertyDescriptor

on_change(attr, *callbacks)

Add a callback on this object to trigger when attr changes.

Parameters
  • attr (str) – an attribute name on this object

  • *callbacks (callable) – callback functions to register

Returns

None

Example:

widget.on_change('value', callback1, callback2, ..., callback_n)
classmethod properties(with_bases=True)

Collect the names of properties on this class.

This method optionally traverses the class hierarchy and includes properties defined on any parent classes.

Parameters

with_bases (bool, optional) – Whether to include properties defined on parent classes in the results. (default: True)

Returns

property names

Return type

set[str]

classmethod properties_containers()

Collect the names of all container properties on this class.

This method always traverses the class hierarchy and includes properties defined on any parent classes.

Returns

names of container properties

Return type

set[str]

classmethod properties_with_refs()

Collect the names of all properties on this class that also have references.

This method always traverses the class hierarchy and includes properties defined on any parent classes.

Returns

names of properties that have references

Return type

set[str]

properties_with_values(include_defaults: bool = True) → Dict[str, Any]

Collect a dict mapping property names to their values.

This method always traverses the class hierarchy and includes properties defined on any parent classes.

Non-serializable properties are skipped and property values are in “serialized” format which may be slightly different from the values you would normally read from the properties; the intent of this method is to return the information needed to losslessly reconstitute the object instance.

Parameters

include_defaults (bool, optional) – Whether to include properties that haven’t been explicitly set since the object was created. (default: True)

Returns

mapping from property names to their values

Return type

dict

query_properties_with_values(query, include_defaults=True)

Query the properties values of HasProps instances with a predicate.

Parameters
  • query (callable) – A callable that accepts property descriptors and returns True or False

  • include_defaults (bool, optional) – Whether to include properties that have not been explicitly set by a user (default: True)

Returns

mapping of property names and values for matching properties

Return type

dict

references()

Returns all Models that this object has references to.

remove_on_change(attr, *callbacks)

Remove a callback from this object

select(selector)

Query this object and all of its references for objects that match the given selector.

Parameters

selector (JSON-like) –

Returns

seq[Model]

select_one(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 :param selector: :type selector: JSON-like

Returns

Model

set_from_json(name, json, models=None, setter=None)

Set a property value on this object from JSON.

Parameters
  • name – (str) : name of the attribute to set

  • json – (JSON-value) : value to set to the attribute to

  • models (dict or None, optional) –

    Mapping of model ids to models (default: None)

    This is needed in cases where the attributes to update also have values that have references.

  • setter (ClientSession or ServerSession or None, optional) –

    This is used to prevent “boomerang” updates to Bokeh apps.

    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.

Returns

None

set_select(selector, updates)

Update objects that match a given selector with the specified attribute/value updates.

Parameters
  • selector (JSON-like) –

  • updates (dict) –

Returns

None

themed_values()

Get any theme-provided overrides.

Results are returned as a dict from property name to value, or None if no theme overrides any values for this instance.

Returns

dict or None

to_json(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.

Parameters

include_defaults (bool) – whether to include attributes that haven’t been changed from the default

to_json_string(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.

Parameters

include_defaults (bool) – whether to include attributes that haven’t been changed from the default

trigger(attr, old, new, hint=None, setter=None)
unapply_theme()

Remove any themed values and restore defaults.

Returns

None

update(**kwargs)

Updates the object’s properties from the given keyword arguments.

Returns

None

Examples

The following are equivalent:

from bokeh.models import Range1d

r = Range1d

# set properties individually:
r.start = 10
r.end = 20

# update properties together:
r.update(start=10, end=20)
update_from_json(json_attributes, models=None, setter=None)

Updates the object’s properties from a JSON attributes dictionary.

Parameters
  • json_attributes – (JSON-dict) : attributes and values to update

  • models (dict or None, optional) –

    Mapping of model ids to models (default: None)

    This is needed in cases where the attributes to update also have values that have references.

  • setter (ClientSession or ServerSession or None, optional) –

    This is used to prevent “boomerang” updates to Bokeh apps.

    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.

Returns

None

property document

The Document this model is attached to (can be None)

property struct

A Bokeh protocol “structure” of this model, i.e. a dict of the form:

{
    'type' : << view model name >>
    'id'   : << unique model id >>
}

Additionally there may be a subtype field if this model is a subtype.

JSON Prototype
{
  "fields": [],
  "id": "10108",
  "js_event_callbacks": {},
  "js_property_callbacks": {},
  "name": null,
  "subscribed_events": [],
  "tags": []
}