django-configurations/configurations/values.py
Jannis Leidel 44476bdd1d Merge remote-tracking branch 'hiisi13/master'
Signed-off-by: Jannis Leidel <jannis@leidel.info>
2015-01-06 23:15:08 +01:00

397 lines
12 KiB
Python

import ast
import copy
import decimal
import os
import sys
from django.core import validators
from django.core.exceptions import ValidationError, ImproperlyConfigured
from django.utils import six
from .utils import import_by_path, getargspec
def setup_value(target, name, value):
actual_value = value.setup(name)
# overwriting the original Value class with the result
setattr(target, name, value.value)
if value.multiple:
for multiple_name, multiple_value in actual_value.items():
setattr(target, multiple_name, multiple_value)
class Value(object):
"""
A single settings value that is able to interpret env variables
and implements a simple validation scheme.
"""
multiple = False
late_binding = False
@property
def value(self):
value = self.default
if not hasattr(self, '_value') and self.environ_name:
self.setup(self.environ_name)
if hasattr(self, '_value'):
value = self._value
return value
@value.setter
def value(self, value):
self._value = value
def __new__(cls, *args, **kwargs):
"""
checks if the creation can end up directly in the final value.
That is the case whenever environ = False or environ_name is given.
"""
instance = object.__new__(cls)
instance.__init__(*args, **kwargs)
if not instance.late_binding:
if (instance.environ and instance.environ_name) \
or (not instance.environ and instance.default):
instance = instance.setup(instance.environ_name)
return instance
def __init__(self, default=None, environ=True, environ_name=None,
environ_prefix='DJANGO', *args, **kwargs):
if 'late_binding' in kwargs:
self.late_binding = kwargs.get('late_binding')
if isinstance(default, Value) and default.default is not None:
self.default = copy.copy(default.default)
else:
self.default = default
self.environ = environ
if environ_prefix and environ_prefix.endswith('_'):
environ_prefix = environ_prefix[:-1]
self.environ_prefix = environ_prefix
self.environ_name = environ_name
def __str__(self):
return str(self.value)
def __repr__(self):
return repr(self.value)
def setup(self, name):
value = self.default
if self.environ:
if not self.environ_name:
environ_name = name.upper()
else:
environ_name = self.environ_name
if self.environ_prefix:
full_environ_name = '{0}_{1}'.format(self.environ_prefix,
environ_name)
else:
full_environ_name = environ_name
if full_environ_name in os.environ:
value = self.to_python(os.environ[full_environ_name])
self.value = value
return value
def to_python(self, value):
"""
Convert the given value of a environment variable into an
appropriate Python representation of the value.
This should be overriden when subclassing.
"""
return value
class MultipleMixin(object):
multiple = True
class BooleanValue(Value):
true_values = ('yes', 'y', 'true', '1')
false_values = ('no', 'n', 'false', '0', '')
def __init__(self, *args, **kwargs):
super(BooleanValue, self).__init__(*args, **kwargs)
if self.default not in (True, False):
raise ValueError('Default value {0!r} is not a '
'boolean value'.format(self.default))
def to_python(self, value):
normalized_value = value.strip().lower()
if normalized_value in self.true_values:
return True
elif normalized_value in self.false_values:
return False
else:
raise ValueError('Cannot interpret '
'boolean value {0!r}'.format(value))
class CastingMixin(object):
exception = (TypeError, ValueError)
message = 'Cannot interpret value {0!r}'
def __init__(self, *args, **kwargs):
super(CastingMixin, self).__init__(*args, **kwargs)
if isinstance(self.caster, six.string_types):
self._caster = import_by_path(self.caster)
elif callable(self.caster):
self._caster = self.caster
else:
error = 'Cannot use caster of {0} ({1!r})'.format(self,
self.caster)
raise ValueError(error)
try:
arg_names = getargspec(self._caster)[0]
self._params = dict((name, kwargs[name])
for name in arg_names
if name in kwargs)
except TypeError:
self._params = {}
def to_python(self, value):
try:
if self._params:
return self._caster(value, **self._params)
else:
return self._caster(value)
except self.exception:
raise ValueError(self.message.format(value))
class IntegerValue(CastingMixin, Value):
caster = int
class FloatValue(CastingMixin, Value):
caster = float
class DecimalValue(CastingMixin, Value):
caster = decimal.Decimal
exception = decimal.InvalidOperation
class ListValue(Value):
converter = None
message = 'Cannot interpret list item {0!r} in list {1!r}'
def __init__(self, *args, **kwargs):
self.separator = kwargs.pop('separator', ',')
converter = kwargs.pop('converter', None)
if converter is not None:
self.converter = converter
super(ListValue, self).__init__(*args, **kwargs)
# make sure the default is a list
if self.default is None:
self.default = []
# initial conversion
if self.converter is not None:
self.default = [self.converter(value) for value in self.default]
def to_python(self, value):
split_value = [v.strip() for v in value.strip().split(self.separator)]
# removing empty items
value_list = filter(None, split_value)
if self.converter is None:
return list(value_list)
converted_values = []
for list_value in value_list:
try:
converted_values.append(self.converter(list_value))
except (TypeError, ValueError):
raise ValueError(self.message.format(list_value, value))
return converted_values
class BackendsValue(ListValue):
def converter(self, value):
try:
import_by_path(value)
except ImproperlyConfigured as err:
six.reraise(ValueError, ValueError(err), sys.exc_info()[2])
return value
class TupleValue(ListValue):
message = 'Cannot interpret tuple item {0!r} in tuple {1!r}'
def __init__(self, *args, **kwargs):
super(TupleValue, self).__init__(*args, **kwargs)
if self.default is None:
self.default = ()
else:
self.default = tuple(self.default)
def to_python(self, value):
return tuple(super(TupleValue, self).to_python(value))
class SetValue(ListValue):
message = 'Cannot interpret set item {0!r} in set {1!r}'
def __init__(self, *args, **kwargs):
super(SetValue, self).__init__(*args, **kwargs)
if self.default is None:
self.default = set()
else:
self.default = set(self.default)
def to_python(self, value):
return set(super(SetValue, self).to_python(value))
class DictValue(Value):
message = 'Cannot interpret dict value {0!r}'
def __init__(self, *args, **kwargs):
super(DictValue, self).__init__(*args, **kwargs)
if self.default is None:
self.default = {}
else:
self.default = dict(self.default)
def to_python(self, value):
value = super(DictValue, self).to_python(value)
if not value:
return {}
try:
evaled_value = ast.literal_eval(value)
except ValueError:
raise ValueError(self.message.format(value))
if not isinstance(evaled_value, dict):
raise ValueError(self.message.format(value))
return evaled_value
class ValidationMixin(object):
def __init__(self, *args, **kwargs):
super(ValidationMixin, self).__init__(*args, **kwargs)
if isinstance(self.validator, six.string_types):
self._validator = import_by_path(self.validator)
elif callable(self.validator):
self._validator = self.validator
else:
raise ValueError('Cannot use validator of '
'{0} ({1!r})'.format(self, self.validator))
if self.default:
self.to_python(self.default)
def to_python(self, value):
try:
self._validator(value)
except ValidationError:
raise ValueError(self.message.format(value))
else:
return value
class EmailValue(ValidationMixin, Value):
message = 'Cannot interpret email value {0!r}'
validator = 'django.core.validators.validate_email'
class URLValue(ValidationMixin, Value):
message = 'Cannot interpret URL value {0!r}'
validator = validators.URLValidator()
class IPValue(ValidationMixin, Value):
message = 'Cannot interpret IP value {0!r}'
validator = 'django.core.validators.validate_ipv46_address'
class RegexValue(ValidationMixin, Value):
message = "Regex doesn't match value {0!r}"
def __init__(self, *args, **kwargs):
regex = kwargs.pop('regex', None)
self.validator = validators.RegexValidator(regex=regex)
super(RegexValue, self).__init__(*args, **kwargs)
class PathValue(Value):
def __init__(self, *args, **kwargs):
self.check_exists = kwargs.pop('check_exists', True)
super(PathValue, self).__init__(*args, **kwargs)
def setup(self, name):
value = super(PathValue, self).setup(name)
value = os.path.expanduser(value)
if self.check_exists and not os.path.exists(value):
raise ValueError('Path {0!r} does not exist.'.format(value))
return os.path.abspath(value)
class SecretValue(Value):
def __init__(self, *args, **kwargs):
kwargs['environ'] = True
super(SecretValue, self).__init__(*args, **kwargs)
if self.default is not None:
raise ValueError('Secret values are only allowed to '
'be set as environment variables')
def setup(self, name):
value = super(SecretValue, self).setup(name)
if not value:
raise ValueError('Secret value {0!r} is not set'.format(name))
return value
class EmailURLValue(CastingMixin, MultipleMixin, Value):
caster = 'dj_email_url.parse'
message = 'Cannot interpret email URL value {0!r}'
late_binding = True
def __init__(self, *args, **kwargs):
kwargs.setdefault('environ', True)
kwargs.setdefault('environ_prefix', None)
kwargs.setdefault('environ_name', 'EMAIL_URL')
super(EmailURLValue, self).__init__(*args, **kwargs)
if self.default is None:
self.default = {}
else:
self.default = self.to_python(self.default)
class DictBackendMixin(Value):
default_alias = 'default'
def __init__(self, *args, **kwargs):
self.alias = kwargs.pop('alias', self.default_alias)
kwargs.setdefault('environ', True)
kwargs.setdefault('environ_prefix', None)
kwargs.setdefault('environ_name', self.environ_name)
super(DictBackendMixin, self).__init__(*args, **kwargs)
if self.default is None:
self.default = {}
else:
self.default = self.to_python(self.default)
def to_python(self, value):
value = super(DictBackendMixin, self).to_python(value)
return {self.alias: value}
class DatabaseURLValue(DictBackendMixin, CastingMixin, Value):
caster = 'dj_database_url.parse'
message = 'Cannot interpret database URL value {0!r}'
environ_name = 'DATABASE_URL'
late_binding = True
class CacheURLValue(DictBackendMixin, CastingMixin, Value):
caster = 'django_cache_url.parse'
message = 'Cannot interpret cache URL value {0!r}'
environ_name = 'CACHE_URL'
late_binding = True
class SearchURLValue(DictBackendMixin, CastingMixin, Value):
caster = 'dj_search_url.parse'
message = 'Cannot interpret Search URL value {0!r}'
environ_name = 'SEARCH_URL'
late_binding = True