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"""
Extensible validation for Python dictionaries.
This module implements Cerberus Validator class
:copyright: 2012-2016 by Nicola Iarocci.
:license: ISC, see LICENSE for more details.
Full documentation is available at http://python-cerberus.org
"""
from __future__ import absolute_import
from ast import literal_eval
from collections import Hashable, Iterable, Mapping, Sequence
from copy import copy
from datetime import date, datetime
import re
from warnings import warn
from cerberus import errors
from cerberus.platform import _int_types, _str_type
from cerberus.schema import (schema_registry, rules_set_registry,
DefinitionSchema, SchemaError)
from cerberus.utils import drop_item_from_tuple, isclass
toy_error_handler = errors.ToyErrorHandler()
def dummy_for_rule_validation(rule_constraints):
def dummy(self, constraint, field, value):
raise RuntimeError('Dummy method called. Its purpose is to hold just'
'validation constraints for a rule in its '
'docstring.')
f = dummy
f.__doc__ = rule_constraints
return f
class DocumentError(Exception):
""" Raised when the target document is missing or has the wrong format """
pass
class _SchemaRuleTypeError(Exception):
""" Raised when a schema (list) validation encounters a mapping.
Not supposed to be used outside this module. """
pass
class Validator(object):
""" Validator class. Normalizes and/or validates any mapping against a
validation-schema which is provided as an argument at class instantiation
or upon calling the :meth:`~cerberus.Validator.validate`,
:meth:`~cerberus.Validator.validated` or
:meth:`~cerberus.Validator.normalized` method. An instance itself is
callable and executes a validation.
All instantiation parameters are optional.
There are the introspective properties :attr:`types`, :attr:`validators`,
:attr:`coercers`, :attr:`default_setters`, :attr:`rules`,
:attr:`normalization_rules` and :attr:`validation_rules`.
The attributes reflecting the available rules are assembled considering
constraints that are defined in the docstrings of rules' methods and is
effectively used as validation schema for :attr:`schema`.
:param schema: See :attr:`~cerberus.Validator.schema`.
Defaults to :obj:`None`.
:type schema: any :term:`mapping`
:param ignore_none_values: See :attr:`~cerberus.Validator.ignore_none_values`.
Defaults to ``False``.
:type ignore_none_values: :class:`bool`
:param allow_unknown: See :attr:`~cerberus.Validator.allow_unknown`.
Defaults to ``False``.
:type allow_unknown: :class:`bool` or any :term:`mapping`
:param purge_unknown: See :attr:`~cerberus.Validator.purge_unknown`.
Defaults to to ``False``.
:type purge_unknown: :class:`bool`
:param error_handler: The error handler that formats the result of
:attr:`~cerberus.Validator.errors`.
When given as two-value tuple with an error-handler
class and a dictionary, the latter is passed to the
initialization of the error handler.
Default: :class:`~cerberus.errors.BasicErrorHandler`.
:type error_handler: class or instance based on
:class:`~cerberus.errors.BaseErrorHandler` or
:class:`tuple`
""" # noqa
mandatory_validations = ('nullable', )
""" Rules that are evaluated on any field, regardless whether defined in
the schema or not.
Type: :class:`tuple` """
priority_validations = ('nullable', 'readonly', 'type')
""" Rules that will be processed in that order before any other and abort
validation of a document's field if return ``True``.
Type: :class:`tuple` """
_valid_schemas = set()
""" A :class:`set` of hashed validation schemas that are legit for a
particular ``Validator`` class. """
def __init__(self, *args, **kwargs):
""" The arguments will be treated as with this signature:
__init__(self, schema=None, ignore_none_values=False,
allow_unknown=False, purge_unknown=False,
error_handler=errors.BasicErrorHandler)
"""
self.document = None
""" The document that is or was recently processed.
Type: any :term:`mapping` """
self._errors = errors.ErrorList()
""" The list of errors that were encountered since the last document
processing was invoked.
Type: :class:`~cerberus.errors.ErrorList` """
self.recent_error = None
""" The last individual error that was submitted.
Type: :class:`~cerberus.errors.ValidationError` """
self.document_error_tree = errors.DocumentErrorTree()
""" A tree representiation of encountered errors following the
structure of the document.
Type: :class:`~cerberus.errors.DocumentErrorTree` """
self.schema_error_tree = errors.SchemaErrorTree()
""" A tree representiation of encountered errors following the
structure of the schema.
Type: :class:`~cerberus.errors.SchemaErrorTree` """
self.document_path = ()
""" The path within the document to the current sub-document.
Type: :class:`tuple` """
self.schema_path = ()
""" The path within the schema to the current sub-schema.
Type: :class:`tuple` """
self.update = False
self.error_handler = self.__init_error_handler(kwargs)
""" The error handler used to format :attr:`~cerberus.Validator.errors`
and process submitted errors with
:meth:`~cerberus.Validator._error`.
Type: :class:`~cerberus.errors.BaseErrorHandler` """
self.__store_config(args, kwargs)
self.schema = kwargs.get('schema', None)
self.allow_unknown = kwargs.get('allow_unknown', False)
def __init_error_handler(self, kwargs):
error_handler = kwargs.pop('error_handler', errors.BasicErrorHandler)
if isinstance(error_handler, tuple):
error_handler, eh_config = error_handler
else:
eh_config = {}
if isclass(error_handler) and \
issubclass(error_handler, errors.BaseErrorHandler):
return error_handler(**eh_config)
elif isinstance(error_handler, errors.BaseErrorHandler):
return error_handler
else:
raise RuntimeError('Invalid error_handler.')
def __store_config(self, args, kwargs):
""" Assign args to kwargs and store configuration. """
signature = ('schema', 'ignore_none_values', 'allow_unknown',
'purge_unknown')
for i, p in enumerate(signature[:len(args)]):
if p in kwargs:
raise TypeError("__init__ got multiple values for argument "
"'%s'" % p)
else:
kwargs[p] = args[i]
self._config = kwargs
""" This dictionary holds the configuration arguments that were used to
initialize the :class:`Validator` instance except the
``error_handler``. """
@classmethod
def clear_caches(cls):
""" Purge the cache of known valid schemas. """
cls._valid_schemas.clear()
def _error(self, *args):
""" Creates and adds one or multiple errors.
:param args: Accepts different argument's signatures.
*1. Bulk addition of errors:*
- :term:`iterable` of
:class:`~cerberus.errors.ValidationError`-instances
The errors will be added to
:attr:`~cerberus.Validator._errors`.
*2. Custom error:*
- the invalid field's name
- the error message
A custom error containing the message will be created and
added to :attr:`~cerberus.Validator._errors`.
There will however be fewer information contained in the
error (no reference to the violated rule and its
constraint).
*3. Defined error:*
- the invalid field's name
- the error-reference, see :mod:`cerberus.errors`
- arbitrary, supplemental information about the error
A :class:`~cerberus.errors.ValidationError` instance will
be created and added to
:attr:`~cerberus.Validator._errors`.
"""
if len(args) == 1:
self._errors.extend(args[0])
self._errors.sort()
for error in args[0]:
self.document_error_tree += error
self.schema_error_tree += error
self.error_handler.emit(error)
elif len(args) == 2 and isinstance(args[1], _str_type):
self._error(args[0], errors.CUSTOM, args[1])
elif len(args) >= 2:
field = args[0]
code = args[1].code
rule = args[1].rule
info = args[2:]
document_path = self.document_path + (field, )
schema_path = self.schema_path
if code != errors.UNKNOWN_FIELD.code and rule is not None:
schema_path += (field, rule)
if not rule:
constraint = None
else:
field_definitions = self._resolve_rules_set(self.schema[field])
if rule == 'nullable':
constraint = field_definitions.get(rule, False)
else:
constraint = field_definitions[rule]
value = self.document.get(field)
self.recent_error = errors.ValidationError(
document_path, schema_path, code, rule, constraint, value, info
)
self._error([self.recent_error])
def _get_child_validator(self, document_crumb=None, schema_crumb=None,
**kwargs):
""" Creates a new instance of Validator-(sub-)class. All initial
parameters of the parent are passed to the initialization, unless
a parameter is given as an explicit *keyword*-parameter.
:param document_crumb: Extends the
:attr:`~cerberus.Validator.document_path`
of the child-validator.
:type document_crumb: :class:`tuple` or :term:`hashable`
:param schema_crumb: Extends the
:attr:`~cerberus.Validator.schema_path`
of the child-validator.
:type schema_crumb: :class:`tuple` or hashable
:param kwargs: Overriding keyword-arguments for initialization.
:type kwargs: :class:`dict`
:return: an instance of ``self.__class__``
"""
child_config = self._config.copy()
child_config.update(kwargs)
if not self.is_child:
child_config['is_child'] = True
child_config['error_handler'] = toy_error_handler
child_config['root_allow_unknown'] = self.allow_unknown
child_config['root_document'] = self.document
child_config['root_schema'] = self.schema
child_validator = self.__class__(**child_config)
if document_crumb is None:
child_validator.document_path = self.document_path
else:
if not isinstance(document_crumb, tuple):
document_crumb = (document_crumb, )
child_validator.document_path = self.document_path + document_crumb
if schema_crumb is None:
child_validator.schema_path = self.schema_path
else:
if not isinstance(schema_crumb, tuple):
schema_crumb = (schema_crumb, )
child_validator.schema_path = self.schema_path + schema_crumb
return child_validator
def __get_rule_handler(self, domain, rule):
methodname = '_{0}_{1}'.format(domain, rule.replace(' ', '_'))
return getattr(self, methodname, None)
def _drop_nodes_from_errorpaths(self, _errors, dp_items, sp_items):
""" Removes nodes by index from an errorpath, relatively to the
basepaths of self.
:param errors: A list of :class:`errors.ValidationError` instances.
:param dp_items: A list of integers, pointing at the nodes to drop from
the :attr:`document_path`.
:param sp_items: Alike ``dp_items``, but for :attr:`schema_path`.
"""
dp_basedepth = len(self.document_path)
sp_basedepth = len(self.schema_path)
for error in _errors:
for i in sorted(dp_items, reverse=True):
error.document_path = \
drop_item_from_tuple(error.document_path, dp_basedepth + i)
for i in sorted(sp_items, reverse=True):
error.schema_path = \
drop_item_from_tuple(error.schema_path, sp_basedepth + i)
if error.child_errors:
self._drop_nodes_from_errorpaths(error.child_errors,
dp_items, sp_items)
def _lookup_field(self, path):
""" Searches for a field as defined by path. This method is used by the
``dependency`` evaluation logic.
:param path: Path elements are separated by a ``.``. A leading ``^``
indicates that the path relates to the document root,
otherwise it relates to the currently evaluated document,
which is possibly a subdocument.
The sequence ``^^`` at the start will be interpreted as a
literal ``^``.
:type path: :class:`str`
:returns: Either the found field name and its value or :obj:`None` for
both.
:rtype: A two-value :class:`tuple`.
"""
if path.startswith('^'):
path = path[1:]
context = self.document if path.startswith('^') \
else self.root_document
else:
context = self.document
parts = path.split('.')
for part in parts:
context = context.get(part)
if context is None:
return None, None
return parts[-1], context
def _resolve_rules_set(self, rules_set):
if isinstance(rules_set, Mapping):
return rules_set
elif isinstance(rules_set, _str_type):
return self.rules_set_registry.get(rules_set)
return None
def _resolve_schema(self, schema):
if isinstance(schema, Mapping):
return schema
elif isinstance(schema, _str_type):
return self.schema_registry.get(schema)
return None
# Properties
@property
def allow_unknown(self):
""" If ``True`` unknown fields that are not defined in the schema will
be ignored. If a mapping with a validation schema is given, any
undefined field will be validated against its rules.
Also see :ref:`allowing-the-unknown`.
Type: :class:`bool` or any :term:`mapping` """
return self._config.get('allow_unknown', False)
@allow_unknown.setter
def allow_unknown(self, value):
if not (self.is_child or isinstance(value, (bool, DefinitionSchema))):
DefinitionSchema(self, {'allow_unknown': value})
self._config['allow_unknown'] = value
@property
def errors(self):
""" The errors of the last processing formatted by the handler that is
bound to :attr:`~cerberus.Validator.error_handler`. """
return self.error_handler(self._errors)
@property
def ignore_none_values(self):
""" Whether to not process :obj:`None`-values in a document or not.
Type: :class:`bool` """
return self._config.get('ignore_none_values', False)
@ignore_none_values.setter
def ignore_none_values(self, value):
self._config['ignore_none_values'] = value
@property
def is_child(self):
""" ``True`` for child-validators obtained with
:meth:`~cerberus.Validator._get_child_validator`.
Type: :class:`bool` """
return self._config.get('is_child', False)
@property
def is_normalized(self):
""" ``True`` if the document is already normalized. """
return self._config.get('is_normalized', False)
@is_normalized.setter
def is_normalized(self, value):
self._config['is_normalized'] = value
@property
def purge_unknown(self):
""" If ``True`` unknown fields will be deleted from the document
unless a validation is called with disabled normalization.
Also see :ref:`purging-unknown-fields`. Type: :class:`bool` """
return self._config.get('purge_unknown', False)
@purge_unknown.setter
def purge_unknown(self, value):
self._config['purge_unknown'] = value
@property
def root_allow_unknown(self):
""" The :attr:`~cerberus.Validator.allow_unknown` attribute of the
first level ancestor of a child validator. """
return self._config.get('root_allow_unknown', self.allow_unknown)
@property
def root_document(self):
""" The :attr:`~cerberus.Validator.document` attribute of the
first level ancestor of a child validator. """
return self._config.get('root_document', self.document)
@property
def rules_set_registry(self):
""" The registry that holds referenced rules sets.
Type: :class:`~cerberus.Registry` """
return self._config.get('rules_set_registry', rules_set_registry)
@rules_set_registry.setter
def rules_set_registry(self, registry):
self._config['rules_set_registry'] = registry
@property
def root_schema(self):
""" The :attr:`~cerberus.Validator.schema` attribute of the
first level ancestor of a child validator. """
return self._config.get('root_schema', self.schema)
@property
def schema(self):
""" The validation schema of a validator. When a schema is passed to
a method, it replaces this attribute.
Type: any :term:`mapping` or :obj:`None` """
return self._schema
@schema.setter
def schema(self, schema):
if schema is None:
self._schema = None
elif self.is_child or isinstance(schema, DefinitionSchema):
self._schema = schema
else:
self._schema = DefinitionSchema(self, schema)
@property
def schema_registry(self):
""" The registry that holds referenced schemas.
Type: :class:`~cerberus.Registry` """
return self._config.get('schema_registry', schema_registry)
@schema_registry.setter
def schema_registry(self, registry):
self._config['schema_registry'] = registry
# Document processing
def __init_processing(self, document, schema=None):
self._errors = errors.ErrorList()
self.recent_error = None
self.document_error_tree = errors.DocumentErrorTree()
self.schema_error_tree = errors.SchemaErrorTree()
self.document = copy(document)
if schema is not None:
self.schema = DefinitionSchema(self, schema)
elif self.schema is None:
if isinstance(self.allow_unknown, Mapping):
self._schema = {}
else:
raise SchemaError(errors.SCHEMA_ERROR_MISSING)
if document is None:
raise DocumentError(errors.DOCUMENT_MISSING)
if not isinstance(document, Mapping):
raise DocumentError(
errors.DOCUMENT_FORMAT.format(document))
self.error_handler.start(self)
# # Normalizing
def normalized(self, document, schema=None, always_return_document=False):
""" Returns the document normalized according to the specified rules
of a schema.
:param document: The document to normalize.
:type document: any :term:`mapping`
:param schema: The validation schema. Defaults to :obj:`None`. If not
provided here, the schema must have been provided at
class instantiation.
:type schema: any :term:`mapping`
:param always_return_document: Return the document, even if an error
occurred. Defaults to: ``False``.
:type always_return_document: :class:`bool`
:return: A normalized copy of the provided mapping or :obj:`None` if an
error occurred during normalization.
"""
self.__init_processing(document, schema)
self.__normalize_mapping(self.document, self.schema)
self.error_handler.end(self)
if self._errors and not always_return_document:
return None
else:
return self.document
def __normalize_mapping(self, mapping, schema):
if isinstance(schema, _str_type):
schema = self._resolve_schema(schema)
schema = schema.copy()
for field in schema:
schema[field] = self._resolve_rules_set(schema[field])
self.__normalize_rename_fields(mapping, schema)
if self.purge_unknown:
self._normalize_purge_unknown(mapping, schema)
# Check `readonly` fields before applying default values because
# a field's schema definition might contain both `readonly` and
# `default`.
self.__validate_readonly_fields(mapping, schema)
self.__normalize_default_fields(mapping, schema)
self._normalize_coerce(mapping, schema)
self.__normalize_containers(mapping, schema)
return mapping
def _normalize_coerce(self, mapping, schema):
""" {'oneof': [
{'type': 'callable'},
{'type': 'list',
'schema': {'oneof': [{'type': 'callable'},
{'type': 'string'}]}},
{'type': 'string'}
]} """
error = errors.COERCION_FAILED
for field in mapping:
if field in schema and 'coerce' in schema[field]:
mapping[field] = self.__normalize_coerce(
schema[field]['coerce'], field, mapping[field], error)
elif isinstance(self.allow_unknown, Mapping) and \
'coerce' in self.allow_unknown:
mapping[field] = self.__normalize_coerce(
self.allow_unknown['coerce'], field, mapping[field], error)
def __normalize_coerce(self, processor, field, value, error):
if isinstance(processor, _str_type):
processor = self.__get_rule_handler('normalize_coerce', processor)
elif isinstance(processor, Iterable):
result = value
for p in processor:
result = self.__normalize_coerce(p, field, result, error)
if errors.COERCION_FAILED in \
self.document_error_tree.fetch_errors_from(
self.document_path + (field,)):
break
return result
try:
return processor(value)
except Exception as e:
self._error(field, error, str(e))
return value
def __normalize_containers(self, mapping, schema):
for field in mapping:
if field not in schema:
continue
# TODO: This check conflates validation and normalization
if isinstance(mapping[field], Mapping):
if 'keyschema' in schema[field]:
self.__normalize_mapping_per_keyschema(
field, mapping, schema[field]['keyschema'])
if 'valueschema' in schema[field]:
self.__normalize_mapping_per_valueschema(
field, mapping, schema[field]['valueschema'])
if set(schema[field]) & set(('allow_unknown', 'purge_unknown',
'schema')):
try:
self.__normalize_mapping_per_schema(
field, mapping, schema)
except _SchemaRuleTypeError:
pass
elif isinstance(mapping[field], _str_type):
continue
elif isinstance(mapping[field], Sequence) and \
'schema' in schema[field]:
self.__normalize_sequence(field, mapping, schema)
def __normalize_mapping_per_keyschema(self, field, mapping, property_rules):
schema = dict(((k, property_rules) for k in mapping[field]))
document = dict(((k, k) for k in mapping[field]))
validator = self._get_child_validator(
document_crumb=field, schema_crumb=(field, 'keyschema'),
schema=schema)
result = validator.normalized(document, always_return_document=True)
if validator._errors:
self._drop_nodes_from_errorpaths(validator._errors, [], [2, 4])
self._error(validator._errors)
for k in result:
if k == result[k]:
continue
if result[k] in mapping[field]:
warn("Normalizing keys of {path}: {key} already exists, "
"its value is replaced."
.format(path='.'.join(self.document_path + (field,)),
key=k))
mapping[field][result[k]] = mapping[field][k]
else:
mapping[field][result[k]] = mapping[field][k]
del mapping[field][k]
def __normalize_mapping_per_valueschema(self, field, mapping, value_rules):
schema = dict(((k, value_rules) for k in mapping[field]))
validator = self._get_child_validator(
document_crumb=field, schema_crumb=(field, 'valueschema'),
schema=schema)
mapping[field] = validator.normalized(mapping[field],
always_return_document=True)
if validator._errors:
self._drop_nodes_from_errorpaths(validator._errors, [], [2])
self._error(validator._errors)
def __normalize_mapping_per_schema(self, field, mapping, schema):
validator = self._get_child_validator(
document_crumb=field, schema_crumb=(field, 'schema'),
schema=schema[field]['schema'],
allow_unknown=schema[field].get('allow_unknown', self.allow_unknown), # noqa
purge_unknown=schema[field].get('purge_unknown', self.purge_unknown)) # noqa
mapping[field] = validator.normalized(mapping[field],
always_return_document=True)
if validator._errors:
self._error(validator._errors)
def __normalize_sequence(self, field, mapping, schema):
schema = dict(((k, schema[field]['schema'])
for k in range(len(mapping[field]))))
document = dict((k, v) for k, v in enumerate(mapping[field]))
validator = self._get_child_validator(
document_crumb=field, schema_crumb=(field, 'schema'),
schema=schema)
result = validator.normalized(document, always_return_document=True)
for i in result:
mapping[field][i] = result[i]
if validator._errors:
self._drop_nodes_from_errorpaths(validator._errors, [], [2])
self._error(validator._errors)
@staticmethod
def _normalize_purge_unknown(mapping, schema):
""" {'type': 'boolean'} """
for field in tuple(mapping):
if field not in schema:
del mapping[field]
return mapping
def __normalize_rename_fields(self, mapping, schema):
for field in tuple(mapping):
if field in schema:
self._normalize_rename(mapping, schema, field)
self._normalize_rename_handler(mapping, schema, field)
elif isinstance(self.allow_unknown, Mapping) and \
'rename_handler' in self.allow_unknown:
self._normalize_rename_handler(
mapping, {field: self.allow_unknown}, field)
return mapping
def _normalize_rename(self, mapping, schema, field):
""" {'type': 'hashable'} """
if 'rename' in schema[field]:
mapping[schema[field]['rename']] = mapping[field]
del mapping[field]
def _normalize_rename_handler(self, mapping, schema, field):
""" {'oneof': [
{'type': 'callable'},
{'type': 'list',
'schema': {'oneof': [{'type': 'callable'},
{'type': 'string'}]}},
{'type': 'string'}
]} """
if 'rename_handler' not in schema[field]:
return
new_name = self.__normalize_coerce(
schema[field]['rename_handler'], field, field,
errors.RENAMING_FAILED)
if new_name != field:
mapping[new_name] = mapping[field]
del mapping[field]
def __validate_readonly_fields(self, mapping, schema):
for field in (x for x in schema if x in mapping and
self._resolve_rules_set(schema[x]).get('readonly')):
self._validate_readonly(schema[field]['readonly'], field,
mapping[field])
def __normalize_default_fields(self, mapping, schema):
fields = [x for x in schema if x not in mapping or
mapping[x] is None and not schema[x].get('nullable', False)]
try:
fields_with_default = [x for x in fields if 'default' in schema[x]]
except TypeError:
raise _SchemaRuleTypeError
for field in fields_with_default:
self._normalize_default(mapping, schema, field)
known_fields_states = set()
fields = [x for x in fields if 'default_setter' in schema[x]]
while fields:
field = fields.pop(0)
try:
self._normalize_default_setter(mapping, schema, field)
except KeyError:
fields.append(field)
except Exception as e:
self._error(field, errors.SETTING_DEFAULT_FAILED, str(e))
fields_state = tuple(fields)
if fields_state in known_fields_states:
for field in fields:
self._error(field, errors.SETTING_DEFAULT_FAILED,
'Circular dependencies of default setters.')
break
else:
known_fields_states.add(fields_state)
def _normalize_default(self, mapping, schema, field):
""" {'nullable': True} """
mapping[field] = schema[field]['default']
def _normalize_default_setter(self, mapping, schema, field):
""" {'oneof': [
{'type': 'callable'},
{'type': 'string'}
]} """
if 'default_setter' in schema[field]:
setter = schema[field]['default_setter']
if isinstance(setter, _str_type):
setter = self.__get_rule_handler('normalize_default_setter',
setter)
mapping[field] = setter(mapping)
# # Validating
def validate(self, document, schema=None, update=False, normalize=True):
""" Normalizes and validates a mapping against a validation-schema of
defined rules.
:param document: The document to normalize.
:type document: any :term:`mapping`
:param schema: The validation schema. Defaults to :obj:`None`. If not
provided here, the schema must have been provided at
class instantiation.
:type schema: any :term:`mapping`
:param update: If ``True``, required fields won't be checked.
:type update: :class:`bool`
:param normalize: If ``True``, normalize the document before validation.
:type normalize: :class:`bool`
:return: ``True`` if validation succeeds, otherwise ``False``. Check
the :func:`errors` property for a list of processing errors.
:rtype: :class:`bool`
"""
self.update = update
self._unrequired_by_excludes = set()
self.__init_processing(document, schema)
if normalize:
self.__normalize_mapping(self.document, self.schema)
self.is_normalized = True
for field in self.document:
if self.ignore_none_values and self.document[field] is None:
continue
definitions = self.schema.get(field)
if definitions is not None:
self.__validate_definitions(definitions, field)
else:
self.__validate_unknown_fields(field)
if not self.update:
self.__validate_required_fields(self.document)
self.error_handler.end(self)
return not bool(self._errors)
__call__ = validate
def validated(self, *args, **kwargs):
""" Wrapper around :meth:`~cerberus.Validator.validate` that returns
the normalized and validated document or :obj:`None` if validation
failed. """
always_return_document = kwargs.pop('always_return_document', False)
self.validate(*args, **kwargs)
if self._errors and not always_return_document:
return None
else:
return self.document
def __validate_unknown_fields(self, field):
if self.allow_unknown:
value = self.document[field]
if isinstance(self.allow_unknown, (Mapping, _str_type)):
# validate that unknown fields matches the schema
# for unknown_fields
schema_crumb = 'allow_unknown' if self.is_child \
else '__allow_unknown__'
validator = self._get_child_validator(
schema_crumb=schema_crumb,
schema={field: self.allow_unknown})
if not validator({field: value}, normalize=False):
self._error(validator._errors)
else:
self._error(field, errors.UNKNOWN_FIELD)
# Remember to keep the validations method below this line
# sorted alphabetically
def __validate_definitions(self, definitions, field):
""" Validate a field's value against its defined rules. """
def validate_rule(rule):
validator = self.__get_rule_handler('validate', rule)
if validator:
return validator(definitions.get(rule, None), field, value)
definitions = self._resolve_rules_set(definitions)
value = self.document[field]
""" _validate_-methods must return True to abort validation. """
prior_rules = tuple((x for x in self.priority_validations
if x in definitions or
x in self.mandatory_validations))
for rule in prior_rules:
if validate_rule(rule):
return
rules = set(definitions)
rules |= set(self.mandatory_validations)
rules -= set(prior_rules + ('allow_unknown', 'required'))
rules -= set(self.normalization_rules)
for rule in rules:
try:
validate_rule(rule)
except _SchemaRuleTypeError:
break
_validate_allow_unknown = dummy_for_rule_validation(
""" {'oneof': [{'type': 'boolean'},
{'type': ['dict', 'string'],
'validator': 'bulk_schema'}]} """)
def _validate_allowed(self, allowed_values, field, value):
""" {'type': 'list'} """
if isinstance(value, Iterable) and not isinstance(value, _str_type):
unallowed = set(value) - set(allowed_values)
if unallowed:
self._error(field, errors.UNALLOWED_VALUES, list(unallowed))
else:
if value not in allowed_values:
self._error(field, errors.UNALLOWED_VALUE, value)
def _validate_dependencies(self, dependencies, field, value):
""" {'type': ['dict', 'hashable', 'hashables']} """
if isinstance(dependencies, _str_type):
dependencies = [dependencies]
if isinstance(dependencies, Sequence):
self.__validate_dependencies_sequence(dependencies, field)
elif isinstance(dependencies, Mapping):
self.__validate_dependencies_mapping(dependencies, field)
if self.document_error_tree.fetch_node_from(
self.schema_path + (field, 'dependencies')) is not None:
return True
def __validate_dependencies_mapping(self, dependencies, field):
validated_dependencies_counter = 0
error_info = {}
for dependency_name, dependency_values in dependencies.items():
if (not isinstance(dependency_values, Sequence) or
isinstance(dependency_values, _str_type)):
dependency_values = [dependency_values]
wanted_field, wanted_field_value = \
self._lookup_field(dependency_name)
if wanted_field_value in dependency_values:
validated_dependencies_counter += 1
else:
error_info.update({dependency_name: wanted_field_value})
if validated_dependencies_counter != len(dependencies):
self._error(field, errors.DEPENDENCIES_FIELD_VALUE, error_info)
def __validate_dependencies_sequence(self, dependencies, field):
for dependency in dependencies:
if self._lookup_field(dependency)[0] is None:
self._error(field, errors.DEPENDENCIES_FIELD, dependency)
def _validate_empty(self, empty, field, value):
""" {'type': 'boolean'} """
if isinstance(value, Iterable) and len(value) == 0 and not empty:
self._error(field, errors.EMPTY_NOT_ALLOWED)
def _validate_excludes(self, excludes, field, value):
""" {'type': ['hashable', 'hashables']} """
if isinstance(excludes, Hashable):
excludes = [excludes]
# Save required field to be checked latter
if 'required' in self.schema[field] and self.schema[field]['required']:
self._unrequired_by_excludes.add(field)
for exclude in excludes:
if (exclude in self.schema and
'required' in self.schema[exclude] and
self.schema[exclude]['required']):
self._unrequired_by_excludes.add(exclude)
if [True for key in excludes if key in self.document]:
# Wrap each field in `excludes` list between quotes
exclusion_str = ', '.join("'{0}'"
.format(word) for word in excludes)
self._error(field, errors.EXCLUDES_FIELD, exclusion_str)
def _validate_forbidden(self, forbidden_values, field, value):
""" {'type': 'list'} """
if isinstance(value, _str_type):
if value in forbidden_values:
self._error(field, errors.FORBIDDEN_VALUE, value)
elif isinstance(value, Sequence):
forbidden = set(value) & set(forbidden_values)
if forbidden:
self._error(field, errors.FORBIDDEN_VALUES, list(forbidden))
elif isinstance(value, int):
if value in forbidden_values:
self._error(field, errors.FORBIDDEN_VALUE, value)
def _validate_items(self, items, field, values):
""" {'type': 'list', 'validator': 'items'} """
if len(items) != len(values):
self._error(field, errors.ITEMS_LENGTH, len(items), len(values))
else:
schema = dict((i, definition) for i, definition in enumerate(items)) # noqa
validator = self._get_child_validator(document_crumb=field,
schema_crumb=(field, 'items'), # noqa
schema=schema)
if not validator(dict((i, value) for i, value in enumerate(values)),
update=self.update, normalize=False):
self._error(field, errors.BAD_ITEMS, validator._errors)
def __validate_logical(self, operator, definitions, field, value):
""" Validates value against all definitions and logs errors according
to the operator. """
valid_counter = 0
_errors = errors.ErrorList()
for i, definition in enumerate(definitions):
schema = {field: definition.copy()}
for rule in ('allow_unknown', 'type'):
if rule not in schema[field] and rule in self.schema[field]:
schema[field][rule] = self.schema[field][rule]
if 'allow_unknown' not in schema[field]:
schema[field]['allow_unknown'] = self.allow_unknown
validator = self._get_child_validator(
schema_crumb=(field, operator, i),
schema=schema, allow_unknown=True)
if validator(self.document, update=self.update, normalize=False):
valid_counter += 1
else:
self._drop_nodes_from_errorpaths(validator._errors, [], [3])
_errors.extend(validator._errors)
return valid_counter, _errors
def _validate_anyof(self, definitions, field, value):
""" {'type': 'list', 'logical': 'anyof'} """
valids, _errors = \
self.__validate_logical('anyof', definitions, field, value)
if valids < 1:
self._error(field, errors.ANYOF, _errors,
valids, len(definitions))
def _validate_allof(self, definitions, field, value):
""" {'type': 'list', 'logical': 'allof'} """
valids, _errors = \
self.__validate_logical('allof', definitions, field, value)
if valids < len(definitions):
self._error(field, errors.ALLOF, _errors,
valids, len(definitions))
def _validate_noneof(self, definitions, field, value):
""" {'type': 'list', 'logical': 'noneof'} """
valids, _errors = \
self.__validate_logical('noneof', definitions, field, value)
if valids > 0:
self._error(field, errors.NONEOF, _errors,
valids, len(definitions))
def _validate_oneof(self, definitions, field, value):
""" {'type': 'list', 'logical': 'oneof'} """
valids, _errors = \
self.__validate_logical('oneof', definitions, field, value)
if valids != 1:
self._error(field, errors.ONEOF, _errors,
valids, len(definitions))
def _validate_max(self, max_value, field, value):
""" {'nullable': False } """
try:
if value > max_value:
self._error(field, errors.MAX_VALUE)
except TypeError:
pass
def _validate_min(self, min_value, field, value):
""" {'nullable': False } """
try:
if value < min_value:
self._error(field, errors.MIN_VALUE)
except TypeError:
pass
def _validate_maxlength(self, max_length, field, value):
""" {'type': 'integer'} """
if isinstance(value, Iterable) and len(value) > max_length:
self._error(field, errors.MAX_LENGTH, len(value))
def _validate_minlength(self, min_length, field, value):
""" {'type': 'integer'} """
if isinstance(value, Iterable) and len(value) < min_length:
self._error(field, errors.MIN_LENGTH, len(value))
def _validate_nullable(self, nullable, field, value):
""" {'type': 'boolean'} """
if value is None:
if nullable:
return True
else:
self._error(field, errors.NOT_NULLABLE)
return True
def _validate_keyschema(self, schema, field, value):
""" {'type': ['dict', 'string'], 'validator': 'bulk_schema',
'forbidden': ['rename', 'rename_handler']} """
if isinstance(value, Mapping):
validator = self._get_child_validator(
document_crumb=field,
schema_crumb=(field, 'keyschema'),
schema=dict(((k, schema) for k in value.keys())))
if not validator(dict(((k, k) for k in value.keys())),
normalize=False):
self._drop_nodes_from_errorpaths(validator._errors,
[], [2, 4])
self._error(field, errors.KEYSCHEMA, validator._errors)
def _validate_readonly(self, readonly, field, value):
""" {'type': 'boolean'} """
if readonly:
if not self.is_normalized:
self._error(field, errors.READONLY_FIELD)
return True
# If the document was normalized (and therefore already been
# checked for readonly fields), we still have to return True
# if an error was filed.
has_error = errors.READONLY_FIELD in \
self.document_error_tree.fetch_errors_from(
self.document_path + (field,))
if self.is_normalized and has_error:
return True
def _validate_regex(self, pattern, field, value):
""" {'type': 'string'} """
if not isinstance(value, _str_type):
return
if not pattern.endswith('$'):
pattern += '$'
re_obj = re.compile(pattern)
if not re_obj.match(value):
self._error(field, errors.REGEX_MISMATCH)
_validate_required = dummy_for_rule_validation(""" {'type': 'boolean'} """)
def __validate_required_fields(self, document):
""" Validates that required fields are not missing.
:param document: The document being validated.
"""
try:
required = set(field for field, definition in self.schema.items()
if self._resolve_rules_set(definition).
get('required') is True)
except AttributeError:
if self.is_child and self.schema_path[-1] == 'schema':
raise _SchemaRuleTypeError
else:
raise
required -= self._unrequired_by_excludes
missing = required - set(field for field in document
if document.get(field) is not None or
not self.ignore_none_values)
for field in missing:
self._error(field, errors.REQUIRED_FIELD)
# At least on field from self._unrequired_by_excludes should be
# present in document
if self._unrequired_by_excludes:
fields = set(field for field in document
if document.get(field) is not None)
if self._unrequired_by_excludes.isdisjoint(fields):
for field in self._unrequired_by_excludes - fields:
self._error(field, errors.REQUIRED_FIELD)
def _validate_schema(self, schema, field, value):
""" {'type': ['dict', 'string'],
'anyof': [{'validator': 'schema'},
{'validator': 'bulk_schema'}]} """
if schema is None:
return
if isinstance(value, Sequence) and not isinstance(value, _str_type):
self.__validate_schema_sequence(field, schema, value)
elif isinstance(value, Mapping):
self.__validate_schema_mapping(field, schema, value)
def __validate_schema_mapping(self, field, schema, value):
schema = self._resolve_schema(schema)
allow_unknown = self.schema[field].get('allow_unknown',
self.allow_unknown)
validator = self._get_child_validator(document_crumb=field,
schema_crumb=(field, 'schema'),
schema=schema,
allow_unknown=allow_unknown)
try:
if not validator(value, update=self.update, normalize=False):
self._error(validator._errors)
except _SchemaRuleTypeError:
self._error(field, errors.BAD_TYPE_FOR_SCHEMA)
raise
def __validate_schema_sequence(self, field, schema, value):
schema = dict(((i, schema) for i in range(len(value))))
validator = self._get_child_validator(
document_crumb=field, schema_crumb=(field, 'schema'),
schema=schema, allow_unknown=self.allow_unknown)
validator(dict(((i, v) for i, v in enumerate(value))),
update=self.update, normalize=False)
if validator._errors:
self._drop_nodes_from_errorpaths(validator._errors, [], [2])
self._error(field, errors.SEQUENCE_SCHEMA, validator._errors)
def _validate_type(self, data_type, field, value):
""" {'type': ['string', 'list']} """
types = [data_type] if isinstance(data_type, _str_type) else data_type
if any(self.__get_rule_handler('validate_type', x)(value)
for x in types):
return
else:
self._error(field, errors.BAD_TYPE)
return True
def _validate_type_boolean(self, value):
if isinstance(value, bool):
return True
def _validate_type_date(self, value):
if isinstance(value, date):
return True
def _validate_type_datetime(self, value):
if isinstance(value, datetime):
return True
def _validate_type_dict(self, value):
if isinstance(value, Mapping):
return True
def _validate_type_float(self, value):
if isinstance(value, (float, _int_types)):
return True
def _validate_type_integer(self, value):
if isinstance(value, _int_types):
return True
def _validate_type_binary(self, value):
if isinstance(value, (bytes, bytearray)):
return True
def _validate_type_list(self, value):
if isinstance(value, Sequence) and not isinstance(
value, _str_type):
return True
def _validate_type_number(self, value):
if isinstance(value, (_int_types, float)) \
and not isinstance(value, bool):
return True
def _validate_type_set(self, value):
if isinstance(value, set):
return True
def _validate_type_string(self, value):
if isinstance(value, _str_type):
return True
def _validate_validator(self, validator, field, value):
""" {'oneof': [
{'type': 'callable'},
{'type': 'list',
'schema': {'oneof': [{'type': 'callable'},
{'type': 'string'}]}},
{'type': 'string'}
]} """
if isinstance(validator, _str_type):
validator = self.__get_rule_handler('validator', validator)
validator(field, value)
elif isinstance(validator, Iterable):
for v in validator:
self._validate_validator(v, field, value)
else:
validator(field, value, self._error)
def _validate_valueschema(self, schema, field, value):
""" {'type': ['dict', 'string'], 'validator': 'bulk_schema',
'forbidden': ['rename', 'rename_handler']} """
schema_crumb = (field, 'valueschema')
if isinstance(value, Mapping):
validator = self._get_child_validator(
document_crumb=field, schema_crumb=schema_crumb,
schema=dict((k, schema) for k in value))
validator(value, update=self.update, normalize=False)
if validator._errors:
self._drop_nodes_from_errorpaths(validator._errors, [], [2])
self._error(field, errors.VALUESCHEMA, validator._errors)
RULE_SCHEMA_SEPARATOR = \
"The rule's arguments are validated against this schema:"
class InspectedValidator(type):
""" Metaclass for all validators """
def __new__(cls, *args):
if '__doc__' not in args[2]:
args[2].update({'__doc__': args[1][0].__doc__})
return super(InspectedValidator, cls).__new__(cls, *args)
def __init__(cls, *args):
def attributes_with_prefix(prefix):
return tuple(x.split('_', 2)[-1] for x in dir(cls)
if x.startswith('_' + prefix))
super(InspectedValidator, cls).__init__(*args)
cls.types, cls.validation_rules = (), {}
for attribute in attributes_with_prefix('validate'):
if attribute.startswith('type_'):
cls.types += (attribute[len('type_'):],)
else:
cls.validation_rules[attribute] = \
cls.__get_rule_schema('_validate_' + attribute)
cls.validation_rules['type']['allowed'] = cls.types
cls.validators = tuple(x for x in attributes_with_prefix('validator'))
x = cls.validation_rules['validator']['oneof']
x[1]['schema']['oneof'][1]['allowed'] = x[2]['allowed'] = cls.validators
for rule in (x for x in cls.mandatory_validations if x != 'nullable'):
cls.validation_rules[rule]['required'] = True
cls.coercers, cls.default_setters, cls.normalization_rules = (), (), {}
for attribute in attributes_with_prefix('normalize'):
if attribute.startswith('coerce_'):
cls.coercers += (attribute[len('coerce_'):],)
elif attribute.startswith('default_setter_'):
cls.default_setters += (attribute[len('default_setter_'):],)
else:
cls.normalization_rules[attribute] = \
cls.__get_rule_schema('_normalize_' + attribute)
for rule in ('coerce', 'rename_handler'):
x = cls.normalization_rules[rule]['oneof']
x[1]['schema']['oneof'][1]['allowed'] = \
x[2]['allowed'] = cls.coercers
cls.normalization_rules['default_setter']['oneof'][1]['allowed'] = \
cls.default_setters
cls.rules = {}
cls.rules.update(cls.validation_rules)
cls.rules.update(cls.normalization_rules)
def __get_rule_schema(cls, method_name):
docstring = getattr(cls, method_name).__doc__
if docstring is None:
result = {}
else:
if RULE_SCHEMA_SEPARATOR in docstring:
docstring = docstring.split(RULE_SCHEMA_SEPARATOR)[1]
try:
result = literal_eval(docstring.strip())
except Exception:
result = {}
if not result:
warn("No validation schema is defined for the arguments of rule "
"'%s'" % method_name.split('_', 2)[-1])
return result
Validator = InspectedValidator('Validator', (Validator,), {})