python-designateclient/designateclient/warlock.py

136 lines
3.9 KiB
Python

# Copyright 2012 Brian Waldon
#
# Licensed 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.
#
# Code copied from Warlock, as warlock depends on jsonschema==0.2
# Hopefully we can upstream the changes ASAP.
#
import copy
import logging
import jsonschema
import six
LOG = logging.getLogger(__name__)
class InvalidOperation(RuntimeError):
pass
class ValidationError(ValueError):
pass
def model_factory(schema):
"""Generate a model class based on the provided JSON Schema
:param schema: dict representing valid JSON schema
"""
schema = copy.deepcopy(schema)
def validator(obj):
"""Apply a JSON schema to an object"""
try:
jsonschema.validate(obj, schema, cls=jsonschema.Draft3Validator)
except jsonschema.ValidationError as e:
raise ValidationError(str(e))
class Model(dict):
"""Self-validating model for arbitrary objects"""
def __init__(self, *args, **kwargs):
d = dict(*args, **kwargs)
# we overload setattr so set this manually
self.__dict__['validator'] = validator
try:
self.validator(d)
except ValidationError as e:
raise ValueError('Validation Error: %s' % str(e))
else:
dict.__init__(self, d)
self.__dict__['changes'] = {}
def __getattr__(self, key):
try:
return self.__getitem__(key)
except KeyError:
raise AttributeError(key)
def __setitem__(self, key, value):
mutation = dict(self.items())
mutation[key] = value
try:
self.validator(mutation)
except ValidationError as e:
raise InvalidOperation(str(e))
dict.__setitem__(self, key, value)
self.__dict__['changes'][key] = value
def __setattr__(self, key, value):
self.__setitem__(key, value)
def clear(self):
raise InvalidOperation()
def pop(self, key, default=None):
raise InvalidOperation()
def popitem(self):
raise InvalidOperation()
def __delitem__(self, key):
raise InvalidOperation()
# NOTE(termie): This is kind of the opposite of what copy usually does
def copy(self):
return copy.deepcopy(dict(self))
def update(self, other):
# NOTE(kiall): It seems update() doesn't update the
# self.__dict__['changes'] dict correctly.
mutation = dict(self.items())
mutation.update(other)
try:
self.validator(mutation)
except ValidationError as e:
raise InvalidOperation(str(e))
dict.update(self, other)
def iteritems(self):
return six.iteritems(copy.deepcopy(dict(self)))
def items(self):
return list(six.iteritems(copy.deepcopy(dict(self))))
def itervalues(self):
return six.itervalues(copy.deepcopy(dict(self)))
def keys(self):
return list(six.iterkeys(copy.deepcopy(dict(self))))
def values(self):
return list(six.itervalues(copy.deepcopy(dict(self))))
@property
def changes(self):
return copy.deepcopy(self.__dict__['changes'])
Model.__name__ = str(schema['title'])
return Model