Added a section to the docs for discussing validators and updated a few links to point to it.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@12101 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This commit is contained in:
Joseph Kocherhans 2010-01-05 06:18:41 +00:00
parent 1e81e2f532
commit cd7da17132
5 changed files with 150 additions and 2 deletions

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@ -182,6 +182,7 @@ Other batteries included
* :ref:`Syndication feeds (RSS/Atom) <ref-contrib-syndication>`
* :ref:`Unicode in Django <ref-unicode>`
* :ref:`Web design helpers <ref-contrib-webdesign>`
* :ref:`Validators <ref-validators>`
The Django open-source project
==============================

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@ -266,7 +266,7 @@ error message keys it uses.
The ``validators`` argument lets you provide a list of validation functions
for this field.
See the :ref:`validators documentation <validators>` for more information.
See the :ref:`validators documentation <ref-validators>` for more information.
Built-in ``Field`` classes
--------------------------

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@ -303,7 +303,7 @@ underscores to spaces. See :ref:`Verbose field names <verbose-field-names>`.
.. attribute:: Field.validators
A list of validators to run for this field.See the :ref:`validators
documentation <validators>` for more information.
documentation <ref-validators>` for more information.
Field types

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@ -27,6 +27,8 @@ The keyword arguments are simply the names of the fields you've defined on your
model. Note that instantiating a model in no way touches your database; for
that, you need to ``save()``.
.. _validating-objects:
Validating objects
==================

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docs/ref/validators.txt Normal file
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.. _ref-validators:
==========
Validators
==========
.. versionadded:: 1.2
Writing validators
==================
A validator is just a callable that takes a value, and raises a
``ValidationError`` if it doesn't meet some criteria. They can be useful for
re-using validation logic between different types of fields.
For example, lets write a validator that only allows even numbers::
from django.core.exceptions import ValidationError
def validate_even(value):
if value % 2 != 0:
raise ValidationError(u'%s is not an even number' % value)
You can then added this to your model fields via the field's ``validators``
argument::
from django.db import models
class MyModel(models.Model):
even_field = models.IntegerField(validators=[validate_even])
Since 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])
How validators are run
======================
See the :ref:`form validation <ref-forms-validation>` for more information on
how validators are run in forms, and :ref:`Validating objects <validating-objects>`
for how they are run in models.
Built-in validators
===================
Django has a collection of callable validators for use with model and form
fields. Many of them are used internally, but they 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)
.. attribute:: regex=None
The regular expression to search for the provided ``value``. Raises a
``ValidationError`` if no match was found.
.. attribute:: code='invalid'
The error code to use if validation fails. Defaults to ``'invalid'``.
.. attribute:: message=None
The error message to use if ``regex`` doesn't match the provided ``value``.
``URLValidator``
----------------
.. class:: URLValidator(verify_exists=False, validator_user_agent=URL_VALIDATOR_USER_AGENT)
A ``RegexValidaor`` that ensures a value looks like a URL, and optionally
verifies that the URL actually exists. Raises an error code of ``'invalid'``
if it doesn't look like a URL, and a code of ``'invalid_link'`` if it doesn't
exist.
.. attribute:: verify_exists=False
If ``verify_exists`` is ``True``, this validator checks that the url actually
exists.
.. attribute:: validator_user_agent=URL_VALIDATOR_USER_AGENT
If ``verify_exists`` is ``True``, use validator_user_agent as the User-agent
for the request. Defaults to ``settings.URL_VALIDATOR_USER_AGENT``.
``validate_email``
------------------
A ``RegexValidator`` instance that ensures a value looks like an email address.
``validate_slug``
-----------------
A ``RegexValidator`` instance that ensures a value consists of only
letters, numbers, underscores, or hyphens.
``validate_ipv4_address``
-------------------------
A ``RegexValidator`` instance that ensures a value looks like an IPv4 address.
``validate_comma_separated_integer_list``
-----------------------------------------
A ``RegexValidator`` instance that ensures a value is a comma separated list
of integers.
``MaxValueValidator``
---------------------
.. class:: MaxValueValidator(max_value)
Raises a ``ValidationError`` with a code of ``'max_value'`` if ``value`` is
greater than ``max_value``.
``MinValueValidator``
---------------------
.. class:: MinValueValidator(min_value)
Raises a ``ValidationError`` with a code of ``'min_value'`` if ``value`` is
less than ``min_value``.
``MaxLengthValidator``
----------------------
.. class:: MaxLengthValidator(max_length)
Raises a ``ValidationError`` with a code of ``'max_length'`` if the length of
``value`` is greater than ``max_length``.
``MinLengthValidator``
----------------------
.. class:: MinLengthValidator(min_length)
Raises a ``ValidationError`` with a code of ``'min_length'`` if the length of
``value`` is less than ``min_length``.