#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements. See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
"""JSON conversion utility functions."""
from __future__ import absolute_import
from past.builtins import long
from past.builtins import unicode
from apache_beam.options.value_provider import ValueProvider
# Protect against environments where apitools library is not available.
# pylint: disable=wrong-import-order, wrong-import-position
try:
from apitools.base.py import extra_types
except ImportError:
extra_types = None
# pylint: enable=wrong-import-order, wrong-import-position
_MAXINT64 = (1 << 63) - 1
_MININT64 = - (1 << 63)
[docs]def get_typed_value_descriptor(obj):
"""For internal use only; no backwards-compatibility guarantees.
Converts a basic type into a @type/value dictionary.
Args:
obj: A basestring, bool, int, or float to be converted.
Returns:
A dictionary containing the keys ``@type`` and ``value`` with the value for
the ``@type`` of appropriate type.
Raises:
~exceptions.TypeError: if the Python object has a type that is not
supported.
"""
if isinstance(obj, (str, unicode)):
type_name = 'Text'
elif isinstance(obj, bool):
type_name = 'Boolean'
elif isinstance(obj, int):
type_name = 'Integer'
elif isinstance(obj, float):
type_name = 'Float'
else:
raise TypeError('Cannot get a type descriptor for %s.' % repr(obj))
return {'@type': 'http://schema.org/%s' % type_name, 'value': obj}
[docs]def to_json_value(obj, with_type=False):
"""For internal use only; no backwards-compatibility guarantees.
Converts Python objects into extra_types.JsonValue objects.
Args:
obj: Python object to be converted. Can be :data:`None`.
with_type: If true then the basic types (``string``, ``int``, ``float``,
``bool``) will be wrapped in ``@type:value`` dictionaries. Otherwise the
straight value is encoded into a ``JsonValue``.
Returns:
A ``JsonValue`` object using ``JsonValue``, ``JsonArray`` and ``JsonObject``
types for the corresponding values, lists, or dictionaries.
Raises:
~exceptions.TypeError: if the Python object contains a type that is not
supported.
The types supported are ``str``, ``bool``, ``list``, ``tuple``, ``dict``, and
``None``. The Dataflow API requires JsonValue(s) in many places, and it is
quite convenient to be able to specify these hierarchical objects using
Python syntax.
"""
if obj is None:
return extra_types.JsonValue(is_null=True)
elif isinstance(obj, (list, tuple)):
return extra_types.JsonValue(
array_value=extra_types.JsonArray(
entries=[to_json_value(o, with_type=with_type) for o in obj]))
elif isinstance(obj, dict):
json_object = extra_types.JsonObject()
for k, v in obj.items():
json_object.properties.append(
extra_types.JsonObject.Property(
key=k, value=to_json_value(v, with_type=with_type)))
return extra_types.JsonValue(object_value=json_object)
elif with_type:
return to_json_value(get_typed_value_descriptor(obj), with_type=False)
elif isinstance(obj, (str, unicode)):
return extra_types.JsonValue(string_value=obj)
elif isinstance(obj, bool):
return extra_types.JsonValue(boolean_value=obj)
elif isinstance(obj, (int, long)):
if _MININT64 <= obj <= _MAXINT64:
return extra_types.JsonValue(integer_value=obj)
else:
raise TypeError('Can not encode {} as a 64-bit integer'.format(obj))
elif isinstance(obj, float):
return extra_types.JsonValue(double_value=obj)
elif isinstance(obj, ValueProvider):
if obj.is_accessible():
return to_json_value(obj.get())
return extra_types.JsonValue(is_null=True)
else:
raise TypeError('Cannot convert %s to a JSON value.' % repr(obj))
[docs]def from_json_value(v):
"""For internal use only; no backwards-compatibility guarantees.
Converts ``extra_types.JsonValue`` objects into Python objects.
Args:
v: ``JsonValue`` object to be converted.
Returns:
A Python object structured as values, lists, and dictionaries corresponding
to ``JsonValue``, ``JsonArray`` and ``JsonObject`` types.
Raises:
~exceptions.TypeError: if the ``JsonValue`` object contains a type that is
not supported.
The types supported are ``str``, ``bool``, ``list``, ``dict``, and ``None``.
The Dataflow API returns JsonValue(s) in many places and it is quite
convenient to be able to convert these hierarchical objects to much simpler
Python objects.
"""
if isinstance(v, extra_types.JsonValue):
if v.string_value is not None:
return v.string_value
elif v.boolean_value is not None:
return v.boolean_value
elif v.integer_value is not None:
return v.integer_value
elif v.double_value is not None:
return v.double_value
elif v.array_value is not None:
return from_json_value(v.array_value)
elif v.object_value is not None:
return from_json_value(v.object_value)
elif v.is_null:
return None
elif isinstance(v, extra_types.JsonArray):
return [from_json_value(e) for e in v.entries]
elif isinstance(v, extra_types.JsonObject):
return {p.key: from_json_value(p.value) for p in v.properties}
raise TypeError('Cannot convert %s from a JSON value.' % repr(v))