django/db/models/fields/__init__.py
import copy
import datetime
import decimal
import operator
import uuid
import warnings
from base64 import b64decode, b64encode
from collections.abc import Iterable
from functools import partialmethod, total_ordering
from django import forms
from django.apps import apps
from django.conf import settings
from django.core import checks, exceptions, validators
from django.db import connection, connections, router
from django.db.models.constants import LOOKUP_SEP
from django.db.models.query_utils import DeferredAttribute, RegisterLookupMixin
from django.db.utils import NotSupportedError
from django.utils import timezone
from django.utils.choices import (
BlankChoiceIterator,
CallableChoiceIterator,
flatten_choices,
normalize_choices,
)
from django.utils.datastructures import DictWrapper
from django.utils.dateparse import (
parse_date,
parse_datetime,
parse_duration,
parse_time,
)
from django.utils.duration import duration_microseconds, duration_string
from django.utils.functional import Promise, cached_property
from django.utils.ipv6 import clean_ipv6_address
from django.utils.text import capfirst
from django.utils.translation import gettext_lazy as _
__all__ = [
"AutoField",
"BLANK_CHOICE_DASH",
"BigAutoField",
"BigIntegerField",
"BinaryField",
"BooleanField",
"CharField",
"CommaSeparatedIntegerField",
"DateField",
"DateTimeField",
"DecimalField",
"DurationField",
"EmailField",
"Empty",
"Field",
"FilePathField",
"FloatField",
"GenericIPAddressField",
"IPAddressField",
"IntegerField",
"NOT_PROVIDED",
"NullBooleanField",
"PositiveBigIntegerField",
"PositiveIntegerField",
"PositiveSmallIntegerField",
"SlugField",
"SmallAutoField",
"SmallIntegerField",
"TextField",
"TimeField",
"URLField",
"UUIDField",
]
class Empty:
pass
class NOT_PROVIDED:
pass
# The values to use for "blank" in SelectFields. Will be appended to the start
# of most "choices" lists.
BLANK_CHOICE_DASH = [("", "---------")]
def _load_field(app_label, model_name, field_name):
return apps.get_model(app_label, model_name)._meta.get_field(field_name)
# A guide to Field parameters:
#
# * name: The name of the field specified in the model.
# * attname: The attribute to use on the model object. This is the same as
# "name", except in the case of ForeignKeys, where "_id" is
# appended.
# * db_column: The db_column specified in the model (or None).
# * column: The database column for this field. This is the same as
# "attname", except if db_column is specified.
#
# Code that introspects values, or does other dynamic things, should use
# attname. For example, this gets the primary key value of object "obj":
#
# getattr(obj, opts.pk.attname)
def _empty(of_cls):
new = Empty()
new.__class__ = of_cls
return new
def return_None():
return None
@total_ordering
class Field(RegisterLookupMixin):
"""Base class for all field types"""
# Designates whether empty strings fundamentally are allowed at the
# database level.
empty_strings_allowed = True
empty_values = list(validators.EMPTY_VALUES)
# These track each time a Field instance is created. Used to retain order.
# The auto_creation_counter is used for fields that Django implicitly
# creates, creation_counter is used for all user-specified fields.
creation_counter = 0
auto_creation_counter = -1
default_validators = [] # Default set of validators
default_error_messages = {
"invalid_choice": _("Value %(value)r is not a valid choice."),
"null": _("This field cannot be null."),
"blank": _("This field cannot be blank."),
"unique": _("%(model_name)s with this %(field_label)s already exists."),
"unique_for_date": _(
# Translators: The 'lookup_type' is one of 'date', 'year' or
# 'month'. Eg: "Title must be unique for pub_date year"
"%(field_label)s must be unique for "
"%(date_field_label)s %(lookup_type)s."
),
}
system_check_deprecated_details = None
system_check_removed_details = None
# Attributes that don't affect a column definition.
# These attributes are ignored when altering the field.
non_db_attrs = (
"blank",
"choices",
"db_column",
"editable",
"error_messages",
"help_text",
"limit_choices_to",
# Database-level options are not supported, see #21961.
"on_delete",
"related_name",
"related_query_name",
"validators",
"verbose_name",
)
# Field flags
hidden = False
many_to_many = None
many_to_one = None
one_to_many = None
one_to_one = None
related_model = None
generated = False
descriptor_class = DeferredAttribute
# Generic field type description, usually overridden by subclasses
def _description(self):
return _("Field of type: %(field_type)s") % {
"field_type": self.__class__.__name__
}
description = property(_description)
def __init__(
self,
verbose_name=None,
name=None,
primary_key=False,
max_length=None,
unique=False,
blank=False,
null=False,
db_index=False,
rel=None,
default=NOT_PROVIDED,
editable=True,
serialize=True,
unique_for_date=None,
unique_for_month=None,
unique_for_year=None,
choices=None,
help_text="",
db_column=None,
db_tablespace=None,
auto_created=False,
validators=(),
error_messages=None,
db_comment=None,
db_default=NOT_PROVIDED,
):
self.name = name
self.verbose_name = verbose_name # May be set by set_attributes_from_name
self._verbose_name = verbose_name # Store original for deconstruction
self.primary_key = primary_key
self.max_length, self._unique = max_length, unique
self.blank, self.null = blank, null
self.remote_field = rel
self.is_relation = self.remote_field is not None
self.default = default
self.db_default = db_default
self.editable = editable
self.serialize = serialize
self.unique_for_date = unique_for_date
self.unique_for_month = unique_for_month
self.unique_for_year = unique_for_year
self.choices = choices
self.help_text = help_text
self.db_index = db_index
self.db_column = db_column
self.db_comment = db_comment
self._db_tablespace = db_tablespace
self.auto_created = auto_created
# Adjust the appropriate creation counter, and save our local copy.
if auto_created:
self.creation_counter = Field.auto_creation_counter
Field.auto_creation_counter -= 1
else:
self.creation_counter = Field.creation_counter
Field.creation_counter += 1
self._validators = list(validators) # Store for deconstruction later
self._error_messages = error_messages # Store for deconstruction later
def __str__(self):
"""
Return "app_label.model_label.field_name" for fields attached to
models.
"""
if not hasattr(self, "model"):
return super().__str__()
model = self.model
return "%s.%s" % (model._meta.label, self.name)
def __repr__(self):
"""Display the module, class, and name of the field."""
path = "%s.%s" % (self.__class__.__module__, self.__class__.__qualname__)
name = getattr(self, "name", None)
if name is not None:
return "<%s: %s>" % (path, name)
return "<%s>" % path
def check(self, **kwargs):
return [
*self._check_field_name(),
*self._check_choices(),
*self._check_db_default(**kwargs),
*self._check_db_index(),
*self._check_db_comment(**kwargs),
*self._check_null_allowed_for_primary_keys(),
*self._check_backend_specific_checks(**kwargs),
*self._check_validators(),
*self._check_deprecation_details(),
]
def _check_field_name(self):
"""
Check if field name is valid, i.e. 1) does not end with an
underscore, 2) does not contain "__" and 3) is not "pk".
"""
if self.name is None:
return []
if self.name.endswith("_"):
return [
checks.Error(
"Field names must not end with an underscore.",
obj=self,
id="fields.E001",
)
]
elif LOOKUP_SEP in self.name:
return [
checks.Error(
'Field names must not contain "%s".' % LOOKUP_SEP,
obj=self,
id="fields.E002",
)
]
elif self.name == "pk":
return [
checks.Error(
"'pk' is a reserved word that cannot be used as a field name.",
obj=self,
id="fields.E003",
)
]
else:
return []
@classmethod
def _choices_is_value(cls, value):
return isinstance(value, (str, Promise)) or not isinstance(value, Iterable)
def _check_choices(self):
if not self.choices:
return []
if not isinstance(self.choices, Iterable) or isinstance(self.choices, str):
return [
checks.Error(
"'choices' must be a mapping (e.g. a dictionary) or an iterable "
"(e.g. a list or tuple).",
obj=self,
id="fields.E004",
)
]
choice_max_length = 0
# Expect [group_name, [value, display]]
for choices_group in self.choices:
try:
group_name, group_choices = choices_group
except (TypeError, ValueError):
# Containing non-pairs
break
try:
if not all(
self._choices_is_value(value) and self._choices_is_value(human_name)
for value, human_name in group_choices
):
break
if self.max_length is not None and group_choices:
choice_max_length = max(
[
choice_max_length,
*(
len(value)
for value, _ in group_choices
if isinstance(value, str)
),
]
)
except (TypeError, ValueError):
# No groups, choices in the form [value, display]
value, human_name = group_name, group_choices
if not self._choices_is_value(value) or not self._choices_is_value(
human_name
):
break
if self.max_length is not None and isinstance(value, str):
choice_max_length = max(choice_max_length, len(value))
# Special case: choices=['ab']
if isinstance(choices_group, str):
break
else:
if self.max_length is not None and choice_max_length > self.max_length:
return [
checks.Error(
"'max_length' is too small to fit the longest value "
"in 'choices' (%d characters)." % choice_max_length,
obj=self,
id="fields.E009",
),
]
return []
return [
checks.Error(
"'choices' must be a mapping of actual values to human readable names "
"or an iterable containing (actual value, human readable name) tuples.",
obj=self,
id="fields.E005",
)
]
def _check_db_default(self, databases=None, **kwargs):
from django.db.models.expressions import Value
if (
self.db_default is NOT_PROVIDED
or isinstance(self.db_default, Value)
or databases is None
):
return []
errors = []
for db in databases:
if not router.allow_migrate_model(db, self.model):
continue
connection = connections[db]
if not getattr(self._db_default_expression, "allowed_default", False) and (
connection.features.supports_expression_defaults
):
msg = f"{self.db_default} cannot be used in db_default."
errors.append(checks.Error(msg, obj=self, id="fields.E012"))
if not (
connection.features.supports_expression_defaults
or "supports_expression_defaults"
in self.model._meta.required_db_features
):
msg = (
f"{connection.display_name} does not support default database "
"values with expressions (db_default)."
)
errors.append(checks.Error(msg, obj=self, id="fields.E011"))
return errors
def _check_db_index(self):
if self.db_index not in (None, True, False):
return [
checks.Error(
"'db_index' must be None, True or False.",
obj=self,
id="fields.E006",
)
]
else:
return []
def _check_db_comment(self, databases=None, **kwargs):
if not self.db_comment or not databases:
return []
errors = []
for db in databases:
if not router.allow_migrate_model(db, self.model):
continue
connection = connections[db]
if not (
connection.features.supports_comments
or "supports_comments" in self.model._meta.required_db_features
):
errors.append(
checks.Warning(
f"{connection.display_name} does not support comments on "
f"columns (db_comment).",
obj=self,
id="fields.W163",
)
)
return errors
def _check_null_allowed_for_primary_keys(self):
if (
self.primary_key
and self.null
and not connection.features.interprets_empty_strings_as_nulls
):
# We cannot reliably check this for backends like Oracle which
# consider NULL and '' to be equal (and thus set up
# character-based fields a little differently).
return [
checks.Error(
"Primary keys must not have null=True.",
hint=(
"Set null=False on the field, or "
"remove primary_key=True argument."
),
obj=self,
id="fields.E007",
)
]
else:
return []
def _check_backend_specific_checks(self, databases=None, **kwargs):
if databases is None:
return []
errors = []
for alias in databases:
if router.allow_migrate_model(alias, self.model):
errors.extend(connections[alias].validation.check_field(self, **kwargs))
return errors
def _check_validators(self):
errors = []
for i, validator in enumerate(self.validators):
if not callable(validator):
errors.append(
checks.Error(
"All 'validators' must be callable.",
hint=(
"validators[{i}] ({repr}) isn't a function or "
"instance of a validator class.".format(
i=i,
repr=repr(validator),
)
),
obj=self,
id="fields.E008",
)
)
return errors
def _check_deprecation_details(self):
if self.system_check_removed_details is not None:
return [
checks.Error(
self.system_check_removed_details.get(
"msg",
"%s has been removed except for support in historical "
"migrations." % self.__class__.__name__,
),
hint=self.system_check_removed_details.get("hint"),
obj=self,
id=self.system_check_removed_details.get("id", "fields.EXXX"),
)
]
elif self.system_check_deprecated_details is not None:
return [
checks.Warning(
self.system_check_deprecated_details.get(
"msg", "%s has been deprecated." % self.__class__.__name__
),
hint=self.system_check_deprecated_details.get("hint"),
obj=self,
id=self.system_check_deprecated_details.get("id", "fields.WXXX"),
)
]
return []
def get_col(self, alias, output_field=None):
if alias == self.model._meta.db_table and (
output_field is None or output_field == self
):
return self.cached_col
from django.db.models.expressions import Col
return Col(alias, self, output_field)
@property
def choices(self):
return self._choices
@choices.setter
def choices(self, value):
self._choices = normalize_choices(value)
@cached_property
def cached_col(self):
from django.db.models.expressions import Col
return Col(self.model._meta.db_table, self)
def select_format(self, compiler, sql, params):
"""
Custom format for select clauses. For example, GIS columns need to be
selected as AsText(table.col) on MySQL as the table.col data can't be
used by Django.
"""
return sql, params
def deconstruct(self):
"""
Return enough information to recreate the field as a 4-tuple:
* The name of the field on the model, if contribute_to_class() has
been run.
* The import path of the field, including the class, e.g.
django.db.models.IntegerField. This should be the most portable
version, so less specific may be better.
* A list of positional arguments.
* A dict of keyword arguments.
Note that the positional or keyword arguments must contain values of
the following types (including inner values of collection types):
* None, bool, str, int, float, complex, set, frozenset, list, tuple,
dict
* UUID
* datetime.datetime (naive), datetime.date
* top-level classes, top-level functions - will be referenced by their
full import path
* Storage instances - these have their own deconstruct() method
This is because the values here must be serialized into a text format
(possibly new Python code, possibly JSON) and these are the only types
with encoding handlers defined.
There's no need to return the exact way the field was instantiated this
time, just ensure that the resulting field is the same - prefer keyword
arguments over positional ones, and omit parameters with their default
values.
"""
# Short-form way of fetching all the default parameters
keywords = {}
possibles = {
"verbose_name": None,
"primary_key": False,
"max_length": None,
"unique": False,
"blank": False,
"null": False,
"db_index": False,
"default": NOT_PROVIDED,
"db_default": NOT_PROVIDED,
"editable": True,
"serialize": True,
"unique_for_date": None,
"unique_for_month": None,
"unique_for_year": None,
"choices": None,
"help_text": "",
"db_column": None,
"db_comment": None,
"db_tablespace": None,
"auto_created": False,
"validators": [],
"error_messages": None,
}
attr_overrides = {
"unique": "_unique",
"error_messages": "_error_messages",
"validators": "_validators",
"verbose_name": "_verbose_name",
"db_tablespace": "_db_tablespace",
}
equals_comparison = {"choices", "validators"}
for name, default in possibles.items():
value = getattr(self, attr_overrides.get(name, name))
if isinstance(value, CallableChoiceIterator):
value = value.func
# Do correct kind of comparison
if name in equals_comparison:
if value != default:
keywords[name] = value
else:
if value is not default:
keywords[name] = value
# Work out path - we shorten it for known Django core fields
path = "%s.%s" % (self.__class__.__module__, self.__class__.__qualname__)
if path.startswith("django.db.models.fields.related"):
path = path.replace("django.db.models.fields.related", "django.db.models")
elif path.startswith("django.db.models.fields.files"):
path = path.replace("django.db.models.fields.files", "django.db.models")
elif path.startswith("django.db.models.fields.generated"):
path = path.replace("django.db.models.fields.generated", "django.db.models")
elif path.startswith("django.db.models.fields.json"):
path = path.replace("django.db.models.fields.json", "django.db.models")
elif path.startswith("django.db.models.fields.proxy"):
path = path.replace("django.db.models.fields.proxy", "django.db.models")
elif path.startswith("django.db.models.fields"):
path = path.replace("django.db.models.fields", "django.db.models")
# Return basic info - other fields should override this.
return (self.name, path, [], keywords)
def clone(self):
"""
Uses deconstruct() to clone a new copy of this Field.
Will not preserve any class attachments/attribute names.
"""
name, path, args, kwargs = self.deconstruct()
return self.__class__(*args, **kwargs)
def __eq__(self, other):
# Needed for @total_ordering
if isinstance(other, Field):
return self.creation_counter == other.creation_counter and getattr(
self, "model", None
) == getattr(other, "model", None)
return NotImplemented
def __lt__(self, other):
# This is needed because bisect does not take a comparison function.
# Order by creation_counter first for backward compatibility.
if isinstance(other, Field):
if (
self.creation_counter != other.creation_counter
or not hasattr(self, "model")
and not hasattr(other, "model")
):
return self.creation_counter < other.creation_counter
elif hasattr(self, "model") != hasattr(other, "model"):
return not hasattr(self, "model") # Order no-model fields first
else:
# creation_counter's are equal, compare only models.
return (self.model._meta.app_label, self.model._meta.model_name) < (
other.model._meta.app_label,
other.model._meta.model_name,
)
return NotImplemented
def __hash__(self):
return hash(self.creation_counter)
def __deepcopy__(self, memodict):
# We don't have to deepcopy very much here, since most things are not
# intended to be altered after initial creation.
obj = copy.copy(self)
if self.remote_field:
obj.remote_field = copy.copy(self.remote_field)
if hasattr(self.remote_field, "field") and self.remote_field.field is self:
obj.remote_field.field = obj
memodict[id(self)] = obj
return obj
def __copy__(self):
# We need to avoid hitting __reduce__, so define this
# slightly weird copy construct.
obj = Empty()
obj.__class__ = self.__class__
obj.__dict__ = self.__dict__.copy()
return obj
def __reduce__(self):
"""
Pickling should return the model._meta.fields instance of the field,
not a new copy of that field. So, use the app registry to load the
model and then the field back.
"""
if not hasattr(self, "model"):
# Fields are sometimes used without attaching them to models (for
# example in aggregation). In this case give back a plain field
# instance. The code below will create a new empty instance of
# class self.__class__, then update its dict with self.__dict__
# values - so, this is very close to normal pickle.
state = self.__dict__.copy()
# The _get_default cached_property can't be pickled due to lambda
# usage.
state.pop("_get_default", None)
return _empty, (self.__class__,), state
return _load_field, (
self.model._meta.app_label,
self.model._meta.object_name,
self.name,
)
def get_pk_value_on_save(self, instance):
"""
Hook to generate new PK values on save. This method is called when
saving instances with no primary key value set. If this method returns
something else than None, then the returned value is used when saving
the new instance.
"""
if self.default:
return self.get_default()
return None
def to_python(self, value):
"""
Convert the input value into the expected Python data type, raising
django.core.exceptions.ValidationError if the data can't be converted.
Return the converted value. Subclasses should override this.
"""
return value
@cached_property
def error_messages(self):
messages = {}
for c in reversed(self.__class__.__mro__):
messages.update(getattr(c, "default_error_messages", {}))
messages.update(self._error_messages or {})
return messages
@cached_property
def validators(self):
"""
Some validators can't be created at field initialization time.
This method provides a way to delay their creation until required.
"""
return [*self.default_validators, *self._validators]
def run_validators(self, value):
if value in self.empty_values:
return
errors = []
for v in self.validators:
try:
v(value)
except exceptions.ValidationError as e:
if hasattr(e, "code") and e.code in self.error_messages:
e.message = self.error_messages[e.code]
errors.extend(e.error_list)
if errors:
raise exceptions.ValidationError(errors)
def validate(self, value, model_instance):
"""
Validate value and raise ValidationError if necessary. Subclasses
should override this to provide validation logic.
"""
if not self.editable:
# Skip validation for non-editable fields.
return
if self.choices is not None and value not in self.empty_values:
for option_key, option_value in self.choices:
if isinstance(option_value, (list, tuple)):
# This is an optgroup, so look inside the group for
# options.
for optgroup_key, optgroup_value in option_value:
if value == optgroup_key:
return
elif value == option_key:
return
raise exceptions.ValidationError(
self.error_messages["invalid_choice"],
code="invalid_choice",
params={"value": value},
)
if value is None and not self.null:
raise exceptions.ValidationError(self.error_messages["null"], code="null")
if not self.blank and value in self.empty_values:
raise exceptions.ValidationError(self.error_messages["blank"], code="blank")
def clean(self, value, model_instance):
"""
Convert the value's type and run validation. Validation errors
from to_python() and validate() are propagated. Return the correct
value if no error is raised.
"""
value = self.to_python(value)
self.validate(value, model_instance)
self.run_validators(value)
return value
def db_type_parameters(self, connection):
return DictWrapper(self.__dict__, connection.ops.quote_name, "qn_")
def db_check(self, connection):
"""
Return the database column check constraint for this field, for the
provided connection. Works the same way as db_type() for the case that
get_internal_type() does not map to a preexisting model field.
"""
data = self.db_type_parameters(connection)
try:
return (
connection.data_type_check_constraints[self.get_internal_type()] % data
)
except KeyError:
return None
def db_type(self, connection):
"""
Return the database column data type for this field, for the provided
connection.
"""
# The default implementation of this method looks at the
# backend-specific data_types dictionary, looking up the field by its
# "internal type".
#
# A Field class can implement the get_internal_type() method to specify
# which *preexisting* Django Field class it's most similar to -- i.e.,
# a custom field might be represented by a TEXT column type, which is
# the same as the TextField Django field type, which means the custom
# field's get_internal_type() returns 'TextField'.
#
# But the limitation of the get_internal_type() / data_types approach
# is that it cannot handle database column types that aren't already
# mapped to one of the built-in Django field types. In this case, you
# can implement db_type() instead of get_internal_type() to specify
# exactly which wacky database column type you want to use.
data = self.db_type_parameters(connection)
try:
column_type = connection.data_types[self.get_internal_type()]
except KeyError:
return None
else:
# column_type is either a single-parameter function or a string.
if callable(column_type):
return column_type(data)
return column_type % data
def rel_db_type(self, connection):
"""
Return the data type that a related field pointing to this field should
use. For example, this method is called by ForeignKey and OneToOneField
to determine its data type.
"""
return self.db_type(connection)
def cast_db_type(self, connection):
"""Return the data type to use in the Cast() function."""
db_type = connection.ops.cast_data_types.get(self.get_internal_type())
if db_type:
return db_type % self.db_type_parameters(connection)
return self.db_type(connection)
def db_parameters(self, connection):
"""
Extension of db_type(), providing a range of different return values
(type, checks). This will look at db_type(), allowing custom model
fields to override it.
"""
type_string = self.db_type(connection)
check_string = self.db_check(connection)
return {
"type": type_string,
"check": check_string,
}
def db_type_suffix(self, connection):
return connection.data_types_suffix.get(self.get_internal_type())
def get_db_converters(self, connection):
if hasattr(self, "from_db_value"):
return [self.from_db_value]
return []
@cached_property
def unique(self):
return self._unique or self.primary_key
@property
def db_tablespace(self):
return self._db_tablespace or settings.DEFAULT_INDEX_TABLESPACE
@property
def db_returning(self):
"""Private API intended only to be used by Django itself."""
return (
self.db_default is not NOT_PROVIDED
and connection.features.can_return_columns_from_insert
)
def set_attributes_from_name(self, name):
self.name = self.name or name
self.attname, self.column = self.get_attname_column()
self.concrete = self.column is not None
if self.verbose_name is None and self.name:
self.verbose_name = self.name.replace("_", " ")
def contribute_to_class(self, cls, name, private_only=False):
"""
Register the field with the model class it belongs to.
If private_only is True, create a separate instance of this field
for every subclass of cls, even if cls is not an abstract model.
"""
self.set_attributes_from_name(name)
self.model = cls
cls._meta.add_field(self, private=private_only)
if self.column:
setattr(cls, self.attname, self.descriptor_class(self))
if self.choices is not None:
# Don't override a get_FOO_display() method defined explicitly on
# this class, but don't check methods derived from inheritance, to
# allow overriding inherited choices. For more complex inheritance
# structures users should override contribute_to_class().
if "get_%s_display" % self.name not in cls.__dict__:
setattr(
cls,
"get_%s_display" % self.name,
partialmethod(cls._get_FIELD_display, field=self),
)
def get_filter_kwargs_for_object(self, obj):
"""
Return a dict that when passed as kwargs to self.model.filter(), would
yield all instances having the same value for this field as obj has.
"""
return {self.name: getattr(obj, self.attname)}
def get_attname(self):
return self.name
def get_attname_column(self):
attname = self.get_attname()
column = self.db_column or attname
return attname, column
def get_internal_type(self):
return self.__class__.__name__
def pre_save(self, model_instance, add):
"""Return field's value just before saving."""
value = getattr(model_instance, self.attname)
if not connection.features.supports_default_keyword_in_insert:
from django.db.models.expressions import DatabaseDefault
if isinstance(value, DatabaseDefault):
return self._db_default_expression
return value
def get_prep_value(self, value):
"""Perform preliminary non-db specific value checks and conversions."""
if isinstance(value, Promise):
value = value._proxy____cast()
return value
def get_db_prep_value(self, value, connection, prepared=False):
"""
Return field's value prepared for interacting with the database backend.
Used by the default implementations of get_db_prep_save().
"""
if not prepared:
value = self.get_prep_value(value)
return value
def get_db_prep_save(self, value, connection):
"""Return field's value prepared for saving into a database."""
if hasattr(value, "as_sql"):
return value
return self.get_db_prep_value(value, connection=connection, prepared=False)
def has_default(self):
"""Return a boolean of whether this field has a default value."""
return self.default is not NOT_PROVIDED
def get_default(self):
"""Return the default value for this field."""
return self._get_default()
@cached_property
def _get_default(self):
if self.has_default():
if callable(self.default):
return self.default
return lambda: self.default
if self.db_default is not NOT_PROVIDED:
from django.db.models.expressions import DatabaseDefault
return DatabaseDefault
if (
not self.empty_strings_allowed
or self.null
and not connection.features.interprets_empty_strings_as_nulls
):
return return_None
return str # return empty string
@cached_property
def _db_default_expression(self):
db_default = self.db_default
if db_default is not NOT_PROVIDED and not hasattr(
db_default, "resolve_expression"
):
from django.db.models.expressions import Value
db_default = Value(db_default, self)
return db_default
def get_choices(
self,
include_blank=True,
blank_choice=BLANK_CHOICE_DASH,
limit_choices_to=None,
ordering=(),
):
"""
Return choices with a default blank choices included, for use
as <select> choices for this field.
"""
if self.choices is not None:
if include_blank:
return BlankChoiceIterator(self.choices, blank_choice)
return self.choices
rel_model = self.remote_field.model
limit_choices_to = limit_choices_to or self.get_limit_choices_to()
choice_func = operator.attrgetter(
self.remote_field.get_related_field().attname
if hasattr(self.remote_field, "get_related_field")
else "pk"
)
qs = rel_model._default_manager.complex_filter(limit_choices_to)
if ordering:
qs = qs.order_by(*ordering)
return (blank_choice if include_blank else []) + [
(choice_func(x), str(x)) for x in qs
]
def value_to_string(self, obj):
"""
Return a string value of this field from the passed obj.
This is used by the serialization framework.
"""
return str(self.value_from_object(obj))
@property
def flatchoices(self):
"""Flattened version of choices tuple."""
return list(flatten_choices(self.choices))
def save_form_data(self, instance, data):
setattr(instance, self.name, data)
def formfield(self, form_class=None, choices_form_class=None, **kwargs):
"""Return a django.forms.Field instance for this field."""
defaults = {
"required": not self.blank,
"label": capfirst(self.verbose_name),
"help_text": self.help_text,
}
if self.has_default():
if callable(self.default):
defaults["initial"] = self.default
defaults["show_hidden_initial"] = True
else:
defaults["initial"] = self.get_default()
if self.choices is not None:
# Fields with choices get special treatment.
include_blank = self.blank or not (
self.has_default() or "initial" in kwargs
)
defaults["choices"] = self.get_choices(include_blank=include_blank)
defaults["coerce"] = self.to_python
if self.null:
defaults["empty_value"] = None
if choices_form_class is not None:
form_class = choices_form_class
else:
form_class = forms.TypedChoiceField
# Many of the subclass-specific formfield arguments (min_value,
# max_value) don't apply for choice fields, so be sure to only pass
# the values that TypedChoiceField will understand.
for k in list(kwargs):
if k not in (
"coerce",
"empty_value",
"choices",
"required",
"widget",
"label",
"initial",
"help_text",
"error_messages",
"show_hidden_initial",
"disabled",
):
del kwargs[k]
defaults.update(kwargs)
if form_class is None:
form_class = forms.CharField
return form_class(**defaults)
def value_from_object(self, obj):
"""Return the value of this field in the given model instance."""
return getattr(obj, self.attname)
def slice_expression(self, expression, start, length):
"""Return a slice of this field."""
raise NotSupportedError("This field does not support slicing.")
class BooleanField(Field):
empty_strings_allowed = False
default_error_messages = {
"invalid": _("“%(value)s” value must be either True or False."),
"invalid_nullable": _("“%(value)s” value must be either True, False, or None."),
}
description = _("Boolean (Either True or False)")
def get_internal_type(self):
return "BooleanField"
def to_python(self, value):
if self.null and value in self.empty_values:
return None
if value in (True, False):
# 1/0 are equal to True/False. bool() converts former to latter.
return bool(value)
if value in ("t", "True", "1"):
return True
if value in ("f", "False", "0"):
return False
raise exceptions.ValidationError(
self.error_messages["invalid_nullable" if self.null else "invalid"],
code="invalid",
params={"value": value},
)
def get_prep_value(self, value):
value = super().get_prep_value(value)
if value is None:
return None
return self.to_python(value)
def formfield(self, **kwargs):
if self.choices is not None:
include_blank = not (self.has_default() or "initial" in kwargs)
defaults = {"choices": self.get_choices(include_blank=include_blank)}
else:
form_class = forms.NullBooleanField if self.null else forms.BooleanField
# In HTML checkboxes, 'required' means "must be checked" which is
# different from the choices case ("must select some value").
# required=False allows unchecked checkboxes.
defaults = {"form_class": form_class, "required": False}
return super().formfield(**{**defaults, **kwargs})
class CharField(Field):
def __init__(self, *args, db_collation=None, **kwargs):
super().__init__(*args, **kwargs)
self.db_collation = db_collation
if self.max_length is not None:
self.validators.append(validators.MaxLengthValidator(self.max_length))
@property
def description(self):
if self.max_length is not None:
return _("String (up to %(max_length)s)")
else:
return _("String (unlimited)")
def check(self, **kwargs):
databases = kwargs.get("databases") or []
return [
*super().check(**kwargs),
*self._check_db_collation(databases),
*self._check_max_length_attribute(**kwargs),
]
def _check_max_length_attribute(self, **kwargs):
if self.max_length is None:
if (
connection.features.supports_unlimited_charfield
or "supports_unlimited_charfield"
in self.model._meta.required_db_features
):
return []
return [
checks.Error(
"CharFields must define a 'max_length' attribute.",
obj=self,
id="fields.E120",
)
]
elif (
not isinstance(self.max_length, int)
or isinstance(self.max_length, bool)
or self.max_length <= 0
):
return [
checks.Error(
"'max_length' must be a positive integer.",
obj=self,
id="fields.E121",
)
]
else:
return []
def _check_db_collation(self, databases):
errors = []
for db in databases:
if not router.allow_migrate_model(db, self.model):
continue
connection = connections[db]
if not (
self.db_collation is None
or "supports_collation_on_charfield"
in self.model._meta.required_db_features
or connection.features.supports_collation_on_charfield
):
errors.append(
checks.Error(
"%s does not support a database collation on "
"CharFields." % connection.display_name,
obj=self,
id="fields.E190",
),
)
return errors
def cast_db_type(self, connection):
if self.max_length is None:
return connection.ops.cast_char_field_without_max_length
return super().cast_db_type(connection)
def db_parameters(self, connection):
db_params = super().db_parameters(connection)
db_params["collation"] = self.db_collation
return db_params
def get_internal_type(self):
return "CharField"
def to_python(self, value):
if isinstance(value, str) or value is None:
return value
return str(value)
def get_prep_value(self, value):
value = super().get_prep_value(value)
return self.to_python(value)
def formfield(self, **kwargs):
# Passing max_length to forms.CharField means that the value's length
# will be validated twice. This is considered acceptable since we want
# the value in the form field (to pass into widget for example).
defaults = {"max_length": self.max_length}
# TODO: Handle multiple backends with different feature flags.
if self.null and not connection.features.interprets_empty_strings_as_nulls:
defaults["empty_value"] = None
defaults.update(kwargs)
return super().formfield(**defaults)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.db_collation:
kwargs["db_collation"] = self.db_collation
return name, path, args, kwargs
def slice_expression(self, expression, start, length):
from django.db.models.functions import Substr
return Substr(expression, start, length)
class CommaSeparatedIntegerField(CharField):
default_validators = [validators.validate_comma_separated_integer_list]
description = _("Comma-separated integers")
system_check_removed_details = {
"msg": (
"CommaSeparatedIntegerField is removed except for support in "
"historical migrations."
),
"hint": (
"Use CharField(validators=[validate_comma_separated_integer_list]) "
"instead."
),
"id": "fields.E901",
}
def _to_naive(value):
if timezone.is_aware(value):
value = timezone.make_naive(value, datetime.timezone.utc)
return value
def _get_naive_now():
return _to_naive(timezone.now())
class DateTimeCheckMixin:
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_mutually_exclusive_options(),
*self._check_fix_default_value(),
]
def _check_mutually_exclusive_options(self):
# auto_now, auto_now_add, and default are mutually exclusive
# options. The use of more than one of these options together
# will trigger an Error
mutually_exclusive_options = [
self.auto_now_add,
self.auto_now,
self.has_default(),
]
enabled_options = [
option not in (None, False) for option in mutually_exclusive_options
].count(True)
if enabled_options > 1:
return [
checks.Error(
"The options auto_now, auto_now_add, and default "
"are mutually exclusive. Only one of these options "
"may be present.",
obj=self,
id="fields.E160",
)
]
else:
return []
def _check_fix_default_value(self):
return []
# Concrete subclasses use this in their implementations of
# _check_fix_default_value().
def _check_if_value_fixed(self, value, now=None):
"""
Check if the given value appears to have been provided as a "fixed"
time value, and include a warning in the returned list if it does. The
value argument must be a date object or aware/naive datetime object. If
now is provided, it must be a naive datetime object.
"""
if now is None:
now = _get_naive_now()
offset = datetime.timedelta(seconds=10)
lower = now - offset
upper = now + offset
if isinstance(value, datetime.datetime):
value = _to_naive(value)
else:
assert isinstance(value, datetime.date)
lower = lower.date()
upper = upper.date()
if lower <= value <= upper:
return [
checks.Warning(
"Fixed default value provided.",
hint=(
"It seems you set a fixed date / time / datetime "
"value as default for this field. This may not be "
"what you want. If you want to have the current date "
"as default, use `django.utils.timezone.now`"
),
obj=self,
id="fields.W161",
)
]
return []
class DateField(DateTimeCheckMixin, Field):
empty_strings_allowed = False
default_error_messages = {
"invalid": _(
"“%(value)s” value has an invalid date format. It must be "
"in YYYY-MM-DD format."
),
"invalid_date": _(
"“%(value)s” value has the correct format (YYYY-MM-DD) "
"but it is an invalid date."
),
}
description = _("Date (without time)")
def __init__(
self, verbose_name=None, name=None, auto_now=False, auto_now_add=False, **kwargs
):
self.auto_now, self.auto_now_add = auto_now, auto_now_add
if auto_now or auto_now_add:
kwargs["editable"] = False
kwargs["blank"] = True
super().__init__(verbose_name, name, **kwargs)
def _check_fix_default_value(self):
"""
Warn that using an actual date or datetime value is probably wrong;
it's only evaluated on server startup.
"""
if not self.has_default():
return []
value = self.default
if isinstance(value, datetime.datetime):
value = _to_naive(value).date()
elif isinstance(value, datetime.date):
pass
else:
# No explicit date / datetime value -- no checks necessary
return []
# At this point, value is a date object.
return self._check_if_value_fixed(value)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.auto_now:
kwargs["auto_now"] = True
if self.auto_now_add:
kwargs["auto_now_add"] = True
if self.auto_now or self.auto_now_add:
del kwargs["editable"]
del kwargs["blank"]
return name, path, args, kwargs
def get_internal_type(self):
return "DateField"
def to_python(self, value):
if value is None:
return value
if isinstance(value, datetime.datetime):
if settings.USE_TZ and timezone.is_aware(value):
# Convert aware datetimes to the default time zone
# before casting them to dates (#17742).
default_timezone = timezone.get_default_timezone()
value = timezone.make_naive(value, default_timezone)
return value.date()
if isinstance(value, datetime.date):
return value
try:
parsed = parse_date(value)
if parsed is not None:
return parsed
except ValueError:
raise exceptions.ValidationError(
self.error_messages["invalid_date"],
code="invalid_date",
params={"value": value},
)
raise exceptions.ValidationError(
self.error_messages["invalid"],
code="invalid",
params={"value": value},
)
def pre_save(self, model_instance, add):
if self.auto_now or (self.auto_now_add and add):
value = datetime.date.today()
setattr(model_instance, self.attname, value)
return value
else:
return super().pre_save(model_instance, add)
def contribute_to_class(self, cls, name, **kwargs):
super().contribute_to_class(cls, name, **kwargs)
if not self.null:
setattr(
cls,
"get_next_by_%s" % self.name,
partialmethod(
cls._get_next_or_previous_by_FIELD, field=self, is_next=True
),
)
setattr(
cls,
"get_previous_by_%s" % self.name,
partialmethod(
cls._get_next_or_previous_by_FIELD, field=self, is_next=False
),
)
def get_prep_value(self, value):
value = super().get_prep_value(value)
return self.to_python(value)
def get_db_prep_value(self, value, connection, prepared=False):
# Casts dates into the format expected by the backend
if not prepared:
value = self.get_prep_value(value)
return connection.ops.adapt_datefield_value(value)
def value_to_string(self, obj):
val = self.value_from_object(obj)
return "" if val is None else val.isoformat()
def formfield(self, **kwargs):
return super().formfield(
**{
"form_class": forms.DateField,
**kwargs,
}
)
class DateTimeField(DateField):
empty_strings_allowed = False
default_error_messages = {
"invalid": _(
"“%(value)s” value has an invalid format. It must be in "
"YYYY-MM-DD HH:MM[:ss[.uuuuuu]][TZ] format."
),
"invalid_date": _(
"“%(value)s” value has the correct format "
"(YYYY-MM-DD) but it is an invalid date."
),
"invalid_datetime": _(
"“%(value)s” value has the correct format "
"(YYYY-MM-DD HH:MM[:ss[.uuuuuu]][TZ]) "
"but it is an invalid date/time."
),
}
description = _("Date (with time)")
# __init__ is inherited from DateField
def _check_fix_default_value(self):
"""
Warn that using an actual date or datetime value is probably wrong;
it's only evaluated on server startup.
"""
if not self.has_default():
return []
value = self.default
if isinstance(value, (datetime.datetime, datetime.date)):
return self._check_if_value_fixed(value)
# No explicit date / datetime value -- no checks necessary.
return []
def get_internal_type(self):
return "DateTimeField"
def to_python(self, value):
if value is None:
return value
if isinstance(value, datetime.datetime):
return value
if isinstance(value, datetime.date):
value = datetime.datetime(value.year, value.month, value.day)
if settings.USE_TZ:
# For backwards compatibility, interpret naive datetimes in
# local time. This won't work during DST change, but we can't
# do much about it, so we let the exceptions percolate up the
# call stack.
try:
name = f"{self.model.__name__}.{self.name}"
except AttributeError:
name = "(unbound)"
warnings.warn(
f"DateTimeField {name} received a naive datetime ({value}) while "
"time zone support is active.",
RuntimeWarning,
)
default_timezone = timezone.get_default_timezone()
value = timezone.make_aware(value, default_timezone)
return value
try:
parsed = parse_datetime(value)
if parsed is not None:
return parsed
except ValueError:
raise exceptions.ValidationError(
self.error_messages["invalid_datetime"],
code="invalid_datetime",
params={"value": value},
)
try:
parsed = parse_date(value)
if parsed is not None:
return datetime.datetime(parsed.year, parsed.month, parsed.day)
except ValueError:
raise exceptions.ValidationError(
self.error_messages["invalid_date"],
code="invalid_date",
params={"value": value},
)
raise exceptions.ValidationError(
self.error_messages["invalid"],
code="invalid",
params={"value": value},
)
def pre_save(self, model_instance, add):
if self.auto_now or (self.auto_now_add and add):
value = timezone.now()
setattr(model_instance, self.attname, value)
return value
else:
return super().pre_save(model_instance, add)
# contribute_to_class is inherited from DateField, it registers
# get_next_by_FOO and get_prev_by_FOO
def get_prep_value(self, value):
value = super().get_prep_value(value)
value = self.to_python(value)
if value is not None and settings.USE_TZ and timezone.is_naive(value):
# For backwards compatibility, interpret naive datetimes in local
# time. This won't work during DST change, but we can't do much
# about it, so we let the exceptions percolate up the call stack.
try:
name = "%s.%s" % (self.model.__name__, self.name)
except AttributeError:
name = "(unbound)"
warnings.warn(
"DateTimeField %s received a naive datetime (%s)"
" while time zone support is active." % (name, value),
RuntimeWarning,
)
default_timezone = timezone.get_default_timezone()
value = timezone.make_aware(value, default_timezone)
return value
def get_db_prep_value(self, value, connection, prepared=False):
# Casts datetimes into the format expected by the backend
if not prepared:
value = self.get_prep_value(value)
return connection.ops.adapt_datetimefield_value(value)
def value_to_string(self, obj):
val = self.value_from_object(obj)
return "" if val is None else val.isoformat()
def formfield(self, **kwargs):
return super().formfield(
**{
"form_class": forms.DateTimeField,
**kwargs,
}
)
class DecimalField(Field):
empty_strings_allowed = False
default_error_messages = {
"invalid": _("“%(value)s” value must be a decimal number."),
}
description = _("Decimal number")
def __init__(
self,
verbose_name=None,
name=None,
max_digits=None,
decimal_places=None,
**kwargs,
):
self.max_digits, self.decimal_places = max_digits, decimal_places
super().__init__(verbose_name, name, **kwargs)
def check(self, **kwargs):
errors = super().check(**kwargs)
digits_errors = [
*self._check_decimal_places(),
*self._check_max_digits(),
]
if not digits_errors:
errors.extend(self._check_decimal_places_and_max_digits(**kwargs))
else:
errors.extend(digits_errors)
return errors
def _check_decimal_places(self):
try:
decimal_places = int(self.decimal_places)
if decimal_places < 0:
raise ValueError()
except TypeError:
return [
checks.Error(
"DecimalFields must define a 'decimal_places' attribute.",
obj=self,
id="fields.E130",
)
]
except ValueError:
return [
checks.Error(
"'decimal_places' must be a non-negative integer.",
obj=self,
id="fields.E131",
)
]
else:
return []
def _check_max_digits(self):
try:
max_digits = int(self.max_digits)
if max_digits <= 0:
raise ValueError()
except TypeError:
return [
checks.Error(
"DecimalFields must define a 'max_digits' attribute.",
obj=self,
id="fields.E132",
)
]
except ValueError:
return [
checks.Error(
"'max_digits' must be a positive integer.",
obj=self,
id="fields.E133",
)
]
else:
return []
def _check_decimal_places_and_max_digits(self, **kwargs):
if int(self.decimal_places) > int(self.max_digits):
return [
checks.Error(
"'max_digits' must be greater or equal to 'decimal_places'.",
obj=self,
id="fields.E134",
)
]
return []
@cached_property
def validators(self):
return super().validators + [
validators.DecimalValidator(self.max_digits, self.decimal_places)
]
@cached_property
def context(self):
return decimal.Context(prec=self.max_digits)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.max_digits is not None:
kwargs["max_digits"] = self.max_digits
if self.decimal_places is not None:
kwargs["decimal_places"] = self.decimal_places
return name, path, args, kwargs
def get_internal_type(self):
return "DecimalField"
def to_python(self, value):
if value is None:
return value
try:
if isinstance(value, float):
decimal_value = self.context.create_decimal_from_float(value)
else:
decimal_value = decimal.Decimal(value)
except (decimal.InvalidOperation, TypeError, ValueError):
raise exceptions.ValidationError(
self.error_messages["invalid"],
code="invalid",
params={"value": value},
)
if not decimal_value.is_finite():
raise exceptions.ValidationError(
self.error_messages["invalid"],
code="invalid",
params={"value": value},
)
return decimal_value
def get_db_prep_save(self, value, connection):
if hasattr(value, "as_sql"):
return value
return connection.ops.adapt_decimalfield_value(
self.to_python(value), self.max_digits, self.decimal_places
)
def get_prep_value(self, value):
value = super().get_prep_value(value)
return self.to_python(value)
def formfield(self, **kwargs):
return super().formfield(
**{
"max_digits": self.max_digits,
"decimal_places": self.decimal_places,
"form_class": forms.DecimalField,
**kwargs,
}
)
class DurationField(Field):
"""
Store timedelta objects.
Use interval on PostgreSQL, INTERVAL DAY TO SECOND on Oracle, and bigint
of microseconds on other databases.
"""
empty_strings_allowed = False
default_error_messages = {
"invalid": _(
"“%(value)s” value has an invalid format. It must be in "
"[DD] [[HH:]MM:]ss[.uuuuuu] format."
)
}
description = _("Duration")
def get_internal_type(self):
return "DurationField"
def to_python(self, value):
if value is None:
return value
if isinstance(value, datetime.timedelta):
return value
try:
parsed = parse_duration(value)
except ValueError:
pass
else:
if parsed is not None:
return parsed
raise exceptions.ValidationError(
self.error_messages["invalid"],
code="invalid",
params={"value": value},
)
def get_db_prep_value(self, value, connection, prepared=False):
if connection.features.has_native_duration_field:
return value
if value is None:
return None
return duration_microseconds(value)
def get_db_converters(self, connection):
converters = []
if not connection.features.has_native_duration_field:
converters.append(connection.ops.convert_durationfield_value)
return converters + super().get_db_converters(connection)
def value_to_string(self, obj):
val = self.value_from_object(obj)
return "" if val is None else duration_string(val)
def formfield(self, **kwargs):
return super().formfield(
**{
"form_class": forms.DurationField,
**kwargs,
}
)
class EmailField(CharField):
default_validators = [validators.validate_email]
description = _("Email address")
def __init__(self, *args, **kwargs):
# max_length=254 to be compliant with RFCs 3696 and 5321
kwargs.setdefault("max_length", 254)
super().__init__(*args, **kwargs)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
# We do not exclude max_length if it matches default as we want to change
# the default in future.
return name, path, args, kwargs
def formfield(self, **kwargs):
# As with CharField, this will cause email validation to be performed
# twice.
return super().formfield(
**{
"form_class": forms.EmailField,
**kwargs,
}
)
class FilePathField(Field):
description = _("File path")
def __init__(
self,
verbose_name=None,
name=None,
path="",
match=None,
recursive=False,
allow_files=True,
allow_folders=False,
**kwargs,
):
self.path, self.match, self.recursive = path, match, recursive
self.allow_files, self.allow_folders = allow_files, allow_folders
kwargs.setdefault("max_length", 100)
super().__init__(verbose_name, name, **kwargs)
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_allowing_files_or_folders(**kwargs),
]
def _check_allowing_files_or_folders(self, **kwargs):
if not self.allow_files and not self.allow_folders:
return [
checks.Error(
"FilePathFields must have either 'allow_files' or 'allow_folders' "
"set to True.",
obj=self,
id="fields.E140",
)
]
return []
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.path != "":
kwargs["path"] = self.path
if self.match is not None:
kwargs["match"] = self.match
if self.recursive is not False:
kwargs["recursive"] = self.recursive
if self.allow_files is not True:
kwargs["allow_files"] = self.allow_files
if self.allow_folders is not False:
kwargs["allow_folders"] = self.allow_folders
if kwargs.get("max_length") == 100:
del kwargs["max_length"]
return name, path, args, kwargs
def get_prep_value(self, value):
value = super().get_prep_value(value)
if value is None:
return None
return str(value)
def formfield(self, **kwargs):
return super().formfield(
**{
"path": self.path() if callable(self.path) else self.path,
"match": self.match,
"recursive": self.recursive,
"form_class": forms.FilePathField,
"allow_files": self.allow_files,
"allow_folders": self.allow_folders,
**kwargs,
}
)
def get_internal_type(self):
return "FilePathField"
class FloatField(Field):
empty_strings_allowed = False
default_error_messages = {
"invalid": _("“%(value)s” value must be a float."),
}
description = _("Floating point number")
def get_prep_value(self, value):
value = super().get_prep_value(value)
if value is None:
return None
try:
return float(value)
except (TypeError, ValueError) as e:
raise e.__class__(
"Field '%s' expected a number but got %r." % (self.name, value),
) from e
def get_internal_type(self):
return "FloatField"
def to_python(self, value):
if value is None:
return value
try:
return float(value)
except (TypeError, ValueError):
raise exceptions.ValidationError(
self.error_messages["invalid"],
code="invalid",
params={"value": value},
)
def formfield(self, **kwargs):
return super().formfield(
**{
"form_class": forms.FloatField,
**kwargs,
}
)
class IntegerField(Field):
empty_strings_allowed = False
default_error_messages = {
"invalid": _("“%(value)s” value must be an integer."),
}
description = _("Integer")
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_max_length_warning(),
]
def _check_max_length_warning(self):
if self.max_length is not None:
return [
checks.Warning(
"'max_length' is ignored when used with %s."
% self.__class__.__name__,
hint="Remove 'max_length' from field",
obj=self,
id="fields.W122",
)
]
return []
@cached_property
def validators(self):
# These validators can't be added at field initialization time since
# they're based on values retrieved from `connection`.
validators_ = super().validators
internal_type = self.get_internal_type()
min_value, max_value = connection.ops.integer_field_range(internal_type)
if min_value is not None and not any(
(
isinstance(validator, validators.MinValueValidator)
and (
validator.limit_value()
if callable(validator.limit_value)
else validator.limit_value
)
>= min_value
)
for validator in validators_
):
validators_.append(validators.MinValueValidator(min_value))
if max_value is not None and not any(
(
isinstance(validator, validators.MaxValueValidator)
and (
validator.limit_value()
if callable(validator.limit_value)
else validator.limit_value
)
<= max_value
)
for validator in validators_
):
validators_.append(validators.MaxValueValidator(max_value))
return validators_
def get_prep_value(self, value):
value = super().get_prep_value(value)
if value is None:
return None
try:
return int(value)
except (TypeError, ValueError) as e:
raise e.__class__(
"Field '%s' expected a number but got %r." % (self.name, value),
) from e
def get_db_prep_value(self, value, connection, prepared=False):
value = super().get_db_prep_value(value, connection, prepared)
return connection.ops.adapt_integerfield_value(value, self.get_internal_type())
def get_internal_type(self):
return "IntegerField"
def to_python(self, value):
if value is None:
return value
try:
return int(value)
except (TypeError, ValueError):
raise exceptions.ValidationError(
self.error_messages["invalid"],
code="invalid",
params={"value": value},
)
def formfield(self, **kwargs):
return super().formfield(
**{
"form_class": forms.IntegerField,
**kwargs,
}
)
class BigIntegerField(IntegerField):
description = _("Big (8 byte) integer")
MAX_BIGINT = 9223372036854775807
def get_internal_type(self):
return "BigIntegerField"
def formfield(self, **kwargs):
return super().formfield(
**{
"min_value": -BigIntegerField.MAX_BIGINT - 1,
"max_value": BigIntegerField.MAX_BIGINT,
**kwargs,
}
)
class SmallIntegerField(IntegerField):
description = _("Small integer")
def get_internal_type(self):
return "SmallIntegerField"
class IPAddressField(Field):
empty_strings_allowed = False
description = _("IPv4 address")
system_check_removed_details = {
"msg": (
"IPAddressField has been removed except for support in "
"historical migrations."
),
"hint": "Use GenericIPAddressField instead.",
"id": "fields.E900",
}
def __init__(self, *args, **kwargs):
kwargs["max_length"] = 15
super().__init__(*args, **kwargs)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
del kwargs["max_length"]
return name, path, args, kwargs
def get_prep_value(self, value):
value = super().get_prep_value(value)
if value is None:
return None
return str(value)
def get_internal_type(self):
return "IPAddressField"
class GenericIPAddressField(Field):
empty_strings_allowed = False
description = _("IP address")
default_error_messages = {"invalid": _("Enter a valid %(protocol)s address.")}
def __init__(
self,
verbose_name=None,
name=None,
protocol="both",
unpack_ipv4=False,
*args,
**kwargs,
):
self.unpack_ipv4 = unpack_ipv4
self.protocol = protocol
self.default_validators = validators.ip_address_validators(
protocol, unpack_ipv4
)
kwargs["max_length"] = 39
super().__init__(verbose_name, name, *args, **kwargs)
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_blank_and_null_values(**kwargs),
]
def _check_blank_and_null_values(self, **kwargs):
if not getattr(self, "null", False) and getattr(self, "blank", False):
return [
checks.Error(
"GenericIPAddressFields cannot have blank=True if null=False, "
"as blank values are stored as nulls.",
obj=self,
id="fields.E150",
)
]
return []
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.unpack_ipv4 is not False:
kwargs["unpack_ipv4"] = self.unpack_ipv4
if self.protocol != "both":
kwargs["protocol"] = self.protocol
if kwargs.get("max_length") == 39:
del kwargs["max_length"]
return name, path, args, kwargs
def get_internal_type(self):
return "GenericIPAddressField"
def to_python(self, value):
if value is None:
return None
if not isinstance(value, str):
value = str(value)
value = value.strip()
if ":" in value:
return clean_ipv6_address(
value, self.unpack_ipv4, self.error_messages["invalid"]
)
return value
def get_db_prep_value(self, value, connection, prepared=False):
if not prepared:
value = self.get_prep_value(value)
return connection.ops.adapt_ipaddressfield_value(value)
def get_prep_value(self, value):
value = super().get_prep_value(value)
if value is None:
return None
if value and ":" in value:
try:
return clean_ipv6_address(value, self.unpack_ipv4)
except exceptions.ValidationError:
pass
return str(value)
def formfield(self, **kwargs):
return super().formfield(
**{
"protocol": self.protocol,
"form_class": forms.GenericIPAddressField,
**kwargs,
}
)
class NullBooleanField(BooleanField):
default_error_messages = {
"invalid": _("“%(value)s” value must be either None, True or False."),
"invalid_nullable": _("“%(value)s” value must be either None, True or False."),
}
description = _("Boolean (Either True, False or None)")
system_check_removed_details = {
"msg": (
"NullBooleanField is removed except for support in historical "
"migrations."
),
"hint": "Use BooleanField(null=True, blank=True) instead.",
"id": "fields.E903",
}
def __init__(self, *args, **kwargs):
kwargs["null"] = True
kwargs["blank"] = True
super().__init__(*args, **kwargs)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
del kwargs["null"]
del kwargs["blank"]
return name, path, args, kwargs
class PositiveIntegerRelDbTypeMixin:
def __init_subclass__(cls, **kwargs):
super().__init_subclass__(**kwargs)
if not hasattr(cls, "integer_field_class"):
cls.integer_field_class = next(
(
parent
for parent in cls.__mro__[1:]
if issubclass(parent, IntegerField)
),
None,
)
def rel_db_type(self, connection):
"""
Return the data type that a related field pointing to this field should
use. In most cases, a foreign key pointing to a positive integer
primary key will have an integer column data type but some databases
(e.g. MySQL) have an unsigned integer type. In that case
(related_fields_match_type=True), the primary key should return its
db_type.
"""
if connection.features.related_fields_match_type:
return self.db_type(connection)
else:
return self.integer_field_class().db_type(connection=connection)
class PositiveBigIntegerField(PositiveIntegerRelDbTypeMixin, BigIntegerField):
description = _("Positive big integer")
def get_internal_type(self):
return "PositiveBigIntegerField"
def formfield(self, **kwargs):
return super().formfield(
**{
"min_value": 0,
**kwargs,
}
)
class PositiveIntegerField(PositiveIntegerRelDbTypeMixin, IntegerField):
description = _("Positive integer")
def get_internal_type(self):
return "PositiveIntegerField"
def formfield(self, **kwargs):
return super().formfield(
**{
"min_value": 0,
**kwargs,
}
)
class PositiveSmallIntegerField(PositiveIntegerRelDbTypeMixin, SmallIntegerField):
description = _("Positive small integer")
def get_internal_type(self):
return "PositiveSmallIntegerField"
def formfield(self, **kwargs):
return super().formfield(
**{
"min_value": 0,
**kwargs,
}
)
class SlugField(CharField):
default_validators = [validators.validate_slug]
description = _("Slug (up to %(max_length)s)")
def __init__(
self, *args, max_length=50, db_index=True, allow_unicode=False, **kwargs
):
self.allow_unicode = allow_unicode
if self.allow_unicode:
self.default_validators = [validators.validate_unicode_slug]
super().__init__(*args, max_length=max_length, db_index=db_index, **kwargs)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if kwargs.get("max_length") == 50:
del kwargs["max_length"]
if self.db_index is False:
kwargs["db_index"] = False
else:
del kwargs["db_index"]
if self.allow_unicode is not False:
kwargs["allow_unicode"] = self.allow_unicode
return name, path, args, kwargs
def get_internal_type(self):
return "SlugField"
def formfield(self, **kwargs):
return super().formfield(
**{
"form_class": forms.SlugField,
"allow_unicode": self.allow_unicode,
**kwargs,
}
)
class TextField(Field):
description = _("Text")
def __init__(self, *args, db_collation=None, **kwargs):
super().__init__(*args, **kwargs)
self.db_collation = db_collation
def check(self, **kwargs):
databases = kwargs.get("databases") or []
return [
*super().check(**kwargs),
*self._check_db_collation(databases),
]
def _check_db_collation(self, databases):
errors = []
for db in databases:
if not router.allow_migrate_model(db, self.model):
continue
connection = connections[db]
if not (
self.db_collation is None
or "supports_collation_on_textfield"
in self.model._meta.required_db_features
or connection.features.supports_collation_on_textfield
):
errors.append(
checks.Error(
"%s does not support a database collation on "
"TextFields." % connection.display_name,
obj=self,
id="fields.E190",
),
)
return errors
def db_parameters(self, connection):
db_params = super().db_parameters(connection)
db_params["collation"] = self.db_collation
return db_params
def get_internal_type(self):
return "TextField"
def to_python(self, value):
if isinstance(value, str) or value is None:
return value
return str(value)
def get_prep_value(self, value):
value = super().get_prep_value(value)
return self.to_python(value)
def formfield(self, **kwargs):
# Passing max_length to forms.CharField means that the value's length
# will be validated twice. This is considered acceptable since we want
# the value in the form field (to pass into widget for example).
return super().formfield(
**{
"max_length": self.max_length,
**({} if self.choices is not None else {"widget": forms.Textarea}),
**kwargs,
}
)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.db_collation:
kwargs["db_collation"] = self.db_collation
return name, path, args, kwargs
def slice_expression(self, expression, start, length):
from django.db.models.functions import Substr
return Substr(expression, start, length)
class TimeField(DateTimeCheckMixin, Field):
empty_strings_allowed = False
default_error_messages = {
"invalid": _(
"“%(value)s” value has an invalid format. It must be in "
"HH:MM[:ss[.uuuuuu]] format."
),
"invalid_time": _(
"“%(value)s” value has the correct format "
"(HH:MM[:ss[.uuuuuu]]) but it is an invalid time."
),
}
description = _("Time")
def __init__(
self, verbose_name=None, name=None, auto_now=False, auto_now_add=False, **kwargs
):
self.auto_now, self.auto_now_add = auto_now, auto_now_add
if auto_now or auto_now_add:
kwargs["editable"] = False
kwargs["blank"] = True
super().__init__(verbose_name, name, **kwargs)
def _check_fix_default_value(self):
"""
Warn that using an actual date or datetime value is probably wrong;
it's only evaluated on server startup.
"""
if not self.has_default():
return []
value = self.default
if isinstance(value, datetime.datetime):
now = None
elif isinstance(value, datetime.time):
now = _get_naive_now()
# This will not use the right date in the race condition where now
# is just before the date change and value is just past 0:00.
value = datetime.datetime.combine(now.date(), value)
else:
# No explicit time / datetime value -- no checks necessary
return []
# At this point, value is a datetime object.
return self._check_if_value_fixed(value, now=now)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.auto_now is not False:
kwargs["auto_now"] = self.auto_now
if self.auto_now_add is not False:
kwargs["auto_now_add"] = self.auto_now_add
if self.auto_now or self.auto_now_add:
del kwargs["blank"]
del kwargs["editable"]
return name, path, args, kwargs
def get_internal_type(self):
return "TimeField"
def to_python(self, value):
if value is None:
return None
if isinstance(value, datetime.time):
return value
if isinstance(value, datetime.datetime):
# Not usually a good idea to pass in a datetime here (it loses
# information), but this can be a side-effect of interacting with a
# database backend (e.g. Oracle), so we'll be accommodating.
return value.time()
try:
parsed = parse_time(value)
if parsed is not None:
return parsed
except ValueError:
raise exceptions.ValidationError(
self.error_messages["invalid_time"],
code="invalid_time",
params={"value": value},
)
raise exceptions.ValidationError(
self.error_messages["invalid"],
code="invalid",
params={"value": value},
)
def pre_save(self, model_instance, add):
if self.auto_now or (self.auto_now_add and add):
value = datetime.datetime.now().time()
setattr(model_instance, self.attname, value)
return value
else:
return super().pre_save(model_instance, add)
def get_prep_value(self, value):
value = super().get_prep_value(value)
return self.to_python(value)
def get_db_prep_value(self, value, connection, prepared=False):
# Casts times into the format expected by the backend
if not prepared:
value = self.get_prep_value(value)
return connection.ops.adapt_timefield_value(value)
def value_to_string(self, obj):
val = self.value_from_object(obj)
return "" if val is None else val.isoformat()
def formfield(self, **kwargs):
return super().formfield(
**{
"form_class": forms.TimeField,
**kwargs,
}
)
class URLField(CharField):
default_validators = [validators.URLValidator()]
description = _("URL")
def __init__(self, verbose_name=None, name=None, **kwargs):
kwargs.setdefault("max_length", 200)
super().__init__(verbose_name, name, **kwargs)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if kwargs.get("max_length") == 200:
del kwargs["max_length"]
return name, path, args, kwargs
def formfield(self, **kwargs):
# As with CharField, this will cause URL validation to be performed
# twice.
return super().formfield(
**{
"form_class": forms.URLField,
**kwargs,
}
)
class BinaryField(Field):
description = _("Raw binary data")
empty_values = [None, b""]
def __init__(self, *args, **kwargs):
kwargs.setdefault("editable", False)
super().__init__(*args, **kwargs)
if self.max_length is not None:
self.validators.append(validators.MaxLengthValidator(self.max_length))
def check(self, **kwargs):
return [*super().check(**kwargs), *self._check_str_default_value()]
def _check_str_default_value(self):
if self.has_default() and isinstance(self.default, str):
return [
checks.Error(
"BinaryField's default cannot be a string. Use bytes "
"content instead.",
obj=self,
id="fields.E170",
)
]
return []
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.editable:
kwargs["editable"] = True
else:
del kwargs["editable"]
return name, path, args, kwargs
def get_internal_type(self):
return "BinaryField"
def get_placeholder(self, value, compiler, connection):
return connection.ops.binary_placeholder_sql(value)
def get_default(self):
if self.has_default() and not callable(self.default):
return self.default
default = super().get_default()
if default == "":
return b""
return default
def get_db_prep_value(self, value, connection, prepared=False):
value = super().get_db_prep_value(value, connection, prepared)
if value is not None:
return connection.Database.Binary(value)
return value
def value_to_string(self, obj):
"""Binary data is serialized as base64"""
return b64encode(self.value_from_object(obj)).decode("ascii")
def to_python(self, value):
# If it's a string, it should be base64-encoded data
if isinstance(value, str):
return memoryview(b64decode(value.encode("ascii")))
return value
class UUIDField(Field):
default_error_messages = {
"invalid": _("“%(value)s” is not a valid UUID."),
}
description = _("Universally unique identifier")
empty_strings_allowed = False
def __init__(self, verbose_name=None, **kwargs):
kwargs["max_length"] = 32
super().__init__(verbose_name, **kwargs)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
del kwargs["max_length"]
return name, path, args, kwargs
def get_internal_type(self):
return "UUIDField"
def get_prep_value(self, value):
value = super().get_prep_value(value)
return self.to_python(value)
def get_db_prep_value(self, value, connection, prepared=False):
if value is None:
return None
if not isinstance(value, uuid.UUID):
value = self.to_python(value)
if connection.features.has_native_uuid_field:
return value
return value.hex
def to_python(self, value):
if value is not None and not isinstance(value, uuid.UUID):
input_form = "int" if isinstance(value, int) else "hex"
try:
return uuid.UUID(**{input_form: value})
except (AttributeError, ValueError):
raise exceptions.ValidationError(
self.error_messages["invalid"],
code="invalid",
params={"value": value},
)
return value
def formfield(self, **kwargs):
return super().formfield(
**{
"form_class": forms.UUIDField,
**kwargs,
}
)
class AutoFieldMixin:
db_returning = True
def __init__(self, *args, **kwargs):
kwargs["blank"] = True
super().__init__(*args, **kwargs)
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_primary_key(),
]
def _check_primary_key(self):
if not self.primary_key:
return [
checks.Error(
"AutoFields must set primary_key=True.",
obj=self,
id="fields.E100",
),
]
else:
return []
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
del kwargs["blank"]
kwargs["primary_key"] = True
return name, path, args, kwargs
def validate(self, value, model_instance):
pass
def get_db_prep_value(self, value, connection, prepared=False):
if not prepared:
value = self.get_prep_value(value)
value = connection.ops.validate_autopk_value(value)
return value
def contribute_to_class(self, cls, name, **kwargs):
if cls._meta.auto_field:
raise ValueError(
"Model %s can't have more than one auto-generated field."
% cls._meta.label
)
super().contribute_to_class(cls, name, **kwargs)
cls._meta.auto_field = self
def formfield(self, **kwargs):
return None
class AutoFieldMeta(type):
"""
Metaclass to maintain backward inheritance compatibility for AutoField.
It is intended that AutoFieldMixin become public API when it is possible to
create a non-integer automatically-generated field using column defaults
stored in the database.
In many areas Django also relies on using isinstance() to check for an
automatically-generated field as a subclass of AutoField. A new flag needs
to be implemented on Field to be used instead.
When these issues have been addressed, this metaclass could be used to
deprecate inheritance from AutoField and use of isinstance() with AutoField
for detecting automatically-generated fields.
"""
@property
def _subclasses(self):
return (BigAutoField, SmallAutoField)
def __instancecheck__(self, instance):
return isinstance(instance, self._subclasses) or super().__instancecheck__(
instance
)
def __subclasscheck__(self, subclass):
return issubclass(subclass, self._subclasses) or super().__subclasscheck__(
subclass
)
class AutoField(AutoFieldMixin, IntegerField, metaclass=AutoFieldMeta):
def get_internal_type(self):
return "AutoField"
def rel_db_type(self, connection):
return IntegerField().db_type(connection=connection)
class BigAutoField(AutoFieldMixin, BigIntegerField):
def get_internal_type(self):
return "BigAutoField"
def rel_db_type(self, connection):
return BigIntegerField().db_type(connection=connection)
class SmallAutoField(AutoFieldMixin, SmallIntegerField):
def get_internal_type(self):
return "SmallAutoField"
def rel_db_type(self, connection):
return SmallIntegerField().db_type(connection=connection)