Source code for bokeh.core.property.validation

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# 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.
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''' Provide the Instance property.

The Instance property is used to construct object graphs of Bokeh models,
where one Bokeh model refers to another.

'''

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# Boilerplate
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from __future__ import absolute_import, division, print_function, unicode_literals

import logging
log = logging.getLogger(__name__)

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# Imports
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# Standard library imports
from functools import wraps

# External imports

# Bokeh imports
from .bases import Property

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# Globals and constants
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__all__ = (
    'validate',
    'without_property_validation',
)

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# General API
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class validate(object):
    ''' Control validation of bokeh properties

    This can be used as a context manager, or as a normal callable

    Args:
        value (bool) : Whether validation should occur or not

    Example:
        .. code-block:: python

            with validate(False):  # do no validate while within this block
                pass

            validate(False)  # don't validate ever

    See Also:
        :func:`~bokeh.core.property.bases.validation_on`: check the state of validation

        :func:`~bokeh.core.properties.without_property_validation`: function decorator

    '''
    def __init__(self, value):
        self.old = Property._should_validate
        Property._should_validate = value

    def __enter__(self):
        pass

    def __exit__(self, typ, value, traceback):
        Property._should_validate = self.old


def without_property_validation(input_function):
    ''' Turn off property validation during update callbacks

    Example:
        .. code-block:: python

            @without_property_validation
            def update(attr, old, new):
                # do things without validation

    See Also:
        :class:`~bokeh.core.properties.validate`: context mangager for more fine-grained control

    '''
    @wraps(input_function)
    def func(*args, **kwargs):
        with validate(False):
            return input_function(*args, **kwargs)
    return func

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# Dev API
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# Private API
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# Code
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