mirror of
https://github.com/django/django.git
synced 2024-11-28 10:48:32 +01:00
253 lines
8.6 KiB
Plaintext
253 lines
8.6 KiB
Plaintext
==========
|
|
Validators
|
|
==========
|
|
|
|
.. module:: django.core.validators
|
|
:synopsis: Validation utilities and base classes
|
|
|
|
Writing validators
|
|
==================
|
|
|
|
A validator is a callable that takes a value and raises a
|
|
:exc:`~django.core.exceptions.ValidationError` if it doesn't meet some
|
|
criteria. Validators can be useful for re-using validation logic between
|
|
different types of fields.
|
|
|
|
For example, here's a validator that only allows even numbers::
|
|
|
|
from django.core.exceptions import ValidationError
|
|
|
|
def validate_even(value):
|
|
if value % 2 != 0:
|
|
raise ValidationError('%s is not an even number' % value)
|
|
|
|
You can add this to a model field via the field's :attr:`~django.db.models.Field.validators`
|
|
argument::
|
|
|
|
from django.db import models
|
|
|
|
class MyModel(models.Model):
|
|
even_field = models.IntegerField(validators=[validate_even])
|
|
|
|
Because values are converted to Python before validators are run, you can even
|
|
use the same validator with forms::
|
|
|
|
from django import forms
|
|
|
|
class MyForm(forms.Form):
|
|
even_field = forms.IntegerField(validators=[validate_even])
|
|
|
|
You can also use a class with a ``__call__()`` method for more complex or
|
|
configurable validators. :class:`RegexValidator`, for example, uses this
|
|
technique. If a class-based validator is used in the
|
|
:attr:`~django.db.models.Field.validators` model field option, you should make
|
|
sure it is :ref:`serializable by the migration framework
|
|
<migration-serializing>` by adding :ref:`deconstruct()
|
|
<custom-deconstruct-method>` and ``__eq__()`` methods.
|
|
|
|
How validators are run
|
|
======================
|
|
|
|
See the :doc:`form validation </ref/forms/validation>` for more information on
|
|
how validators are run in forms, and :ref:`Validating objects
|
|
<validating-objects>` for how they're run in models. Note that validators will
|
|
not be run automatically when you save a model, but if you are using a
|
|
:class:`~django.forms.ModelForm`, it will run your validators on any fields
|
|
that are included in your form. See the
|
|
:doc:`ModelForm documentation </topics/forms/modelforms>` for information on
|
|
how model validation interacts with forms.
|
|
|
|
Built-in validators
|
|
===================
|
|
|
|
The :mod:`django.core.validators` module contains a collection of callable
|
|
validators for use with model and form fields. They're used internally but
|
|
are available for use with your own fields, too. They can be used in addition
|
|
to, or in lieu of custom ``field.clean()`` methods.
|
|
|
|
``RegexValidator``
|
|
------------------
|
|
.. class:: RegexValidator([regex=None, message=None, code=None, inverse_match=None, flags=0])
|
|
|
|
:param regex: If not ``None``, overrides :attr:`regex`. Can be a regular
|
|
expression string or a pre-compiled regular expression.
|
|
:param message: If not ``None``, overrides :attr:`.message`.
|
|
:param code: If not ``None``, overrides :attr:`code`.
|
|
:param inverse_match: If not ``None``, overrides :attr:`inverse_match`.
|
|
:param flags: If not ``None``, overrides :attr:`flags`. In that case,
|
|
:attr:`regex` must be a regular expression string, or
|
|
:exc:`TypeError` is raised.
|
|
|
|
.. attribute:: regex
|
|
|
|
The regular expression pattern to search for the provided ``value``,
|
|
or a pre-compiled regular expression. By default, raises a
|
|
:exc:`~django.core.exceptions.ValidationError` with :attr:`message`
|
|
and :attr:`code` if a match is not found. That standard behavior can
|
|
be reversed by setting :attr:`inverse_match` to ``True``, in which case
|
|
the :exc:`~django.core.exceptions.ValidationError` is raised when a
|
|
match **is** found. By default, matches any string (including an empty
|
|
string).
|
|
|
|
.. attribute:: message
|
|
|
|
The error message used by
|
|
:exc:`~django.core.exceptions.ValidationError` if validation fails.
|
|
Defaults to ``"Enter a valid value"``.
|
|
|
|
.. attribute:: code
|
|
|
|
The error code used by :exc:`~django.core.exceptions.ValidationError`
|
|
if validation fails. Defaults to ``"invalid"``.
|
|
|
|
.. attribute:: inverse_match
|
|
|
|
.. versionadded:: 1.7
|
|
|
|
The match mode for :attr:`regex`. Defaults to ``False``.
|
|
|
|
.. attribute:: flags
|
|
|
|
.. versionadded:: 1.7
|
|
|
|
The flags used when compiling the regular expression string :attr:`regex`.
|
|
If :attr:`regex` is a pre-compiled regular expression, and :attr:`flags` is overridden,
|
|
:exc:`TypeError` is raised.
|
|
Defaults to `0`.
|
|
|
|
``EmailValidator``
|
|
------------------
|
|
|
|
.. class:: EmailValidator([message=None, code=None, whitelist=None])
|
|
|
|
:param message: If not ``None``, overrides :attr:`.message`.
|
|
:param code: If not ``None``, overrides :attr:`code`.
|
|
:param whitelist: If not ``None``, overrides :attr:`whitelist`.
|
|
|
|
.. attribute:: message
|
|
|
|
The error message used by
|
|
:exc:`~django.core.exceptions.ValidationError` if validation fails.
|
|
Defaults to ``"Enter a valid email address"``.
|
|
|
|
.. attribute:: code
|
|
|
|
The error code used by :exc:`~django.core.exceptions.ValidationError`
|
|
if validation fails. Defaults to ``"invalid"``.
|
|
|
|
.. attribute:: whitelist
|
|
|
|
Whitelist of email domains to allow. By default, a regular expression
|
|
(the ``domain_regex`` attribute) is used to validate whatever appears
|
|
after the @ sign. However, if that string appears in the whitelist, this
|
|
validation is bypassed. If not provided, the default whitelist is
|
|
``['localhost']``. Other domains that don't contain a dot won't pass
|
|
validation, so you'd need to whitelist them as necessary.
|
|
|
|
``URLValidator``
|
|
----------------
|
|
.. class:: URLValidator([schemes=None, regex=None, message=None, code=None])
|
|
|
|
A :class:`RegexValidator` that ensures a value looks like a URL, and raises
|
|
an error code of ``'invalid'`` if it doesn't. In addition to the optional
|
|
arguments of its parent :class:`RegexValidator` class, ``URLValidator``
|
|
accepts an extra optional attribute:
|
|
|
|
.. attribute:: schemes
|
|
|
|
URL/URI scheme list to validate against. If not provided, the default
|
|
list is ``['http', 'https', 'ftp', 'ftps']``. As a reference, the IANA
|
|
Web site provides a full list of `valid URI schemes`_.
|
|
|
|
.. _valid URI schemes: https://www.iana.org/assignments/uri-schemes/uri-schemes.xhtml
|
|
|
|
.. versionchanged:: 1.7
|
|
|
|
The optional ``schemes`` attribute was added.
|
|
|
|
``validate_email``
|
|
------------------
|
|
.. data:: validate_email
|
|
|
|
An :class:`EmailValidator` instance without any customizations.
|
|
|
|
``validate_slug``
|
|
-----------------
|
|
.. data:: validate_slug
|
|
|
|
A :class:`RegexValidator` instance that ensures a value consists of only
|
|
letters, numbers, underscores or hyphens.
|
|
|
|
``validate_ipv4_address``
|
|
-------------------------
|
|
.. data:: validate_ipv4_address
|
|
|
|
A :class:`RegexValidator` instance that ensures a value looks like an IPv4
|
|
address.
|
|
|
|
``validate_ipv6_address``
|
|
-------------------------
|
|
|
|
.. data:: validate_ipv6_address
|
|
|
|
Uses ``django.utils.ipv6`` to check the validity of an IPv6 address.
|
|
|
|
``validate_ipv46_address``
|
|
--------------------------
|
|
|
|
.. data:: validate_ipv46_address
|
|
|
|
Uses both ``validate_ipv4_address`` and ``validate_ipv6_address`` to
|
|
ensure a value is either a valid IPv4 or IPv6 address.
|
|
|
|
``validate_comma_separated_integer_list``
|
|
-----------------------------------------
|
|
.. data:: validate_comma_separated_integer_list
|
|
|
|
A :class:`RegexValidator` instance that ensures a value is a
|
|
comma-separated list of integers.
|
|
|
|
``MaxValueValidator``
|
|
---------------------
|
|
.. class:: MaxValueValidator(max_value, message=None)
|
|
|
|
Raises a :exc:`~django.core.exceptions.ValidationError` with a code of
|
|
``'max_value'`` if ``value`` is greater than ``max_value``.
|
|
|
|
.. versionchanged:: 1.8
|
|
|
|
The ``message`` parameter was added.
|
|
|
|
``MinValueValidator``
|
|
---------------------
|
|
.. class:: MinValueValidator(min_value, message=None)
|
|
|
|
Raises a :exc:`~django.core.exceptions.ValidationError` with a code of
|
|
``'min_value'`` if ``value`` is less than ``min_value``.
|
|
|
|
.. versionchanged:: 1.8
|
|
|
|
The ``message`` parameter was added.
|
|
|
|
``MaxLengthValidator``
|
|
----------------------
|
|
.. class:: MaxLengthValidator(max_length, message=None)
|
|
|
|
Raises a :exc:`~django.core.exceptions.ValidationError` with a code of
|
|
``'max_length'`` if the length of ``value`` is greater than ``max_length``.
|
|
|
|
.. versionchanged:: 1.8
|
|
|
|
The ``message`` parameter was added.
|
|
|
|
``MinLengthValidator``
|
|
----------------------
|
|
.. class:: MinLengthValidator(min_length, message=None)
|
|
|
|
Raises a :exc:`~django.core.exceptions.ValidationError` with a code of
|
|
``'min_length'`` if the length of ``value`` is less than ``min_length``.
|
|
|
|
.. versionchanged:: 1.8
|
|
|
|
The ``message`` parameter was added.
|