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django/docs/ref/forms/models.txt
Mustafa Pirbhai 183fcebf88 Fixed #35831 -- Documented the model form meta API in model form reference docs.
Co-authored-by: Jonathan <3218047+jernwerber@users.noreply.github.com>
Co-authored-by: Mustafa <117516335+mspirbhai@users.noreply.github.com>
2025-08-29 08:58:58 +02:00

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===========
Model forms
===========
.. module:: django.forms.models
:synopsis: ModelForm API reference for inner ``Meta`` class and factory
functions
.. currentmodule:: django.forms
``ModelForm`` API reference. For introductory material about using a
``ModelForm``, see the :doc:`/topics/forms/modelforms` topic guide.
Model form ``Meta`` API
=======================
.. class:: ModelFormOptions
The ``_meta`` API is used to build forms that reflect a Django model. It is
accessible through the ``_meta`` attribute of each model form, and is an
``django.forms.models.ModelFormOptions`` instance.
The structure of the generated form can be customized by defining metadata
options as attributes of an inner ``Meta`` class. For example::
from django.forms import ModelForm
from myapp.models import Book
class BookForm(ModelForm):
class Meta:
model = Book
fields = ["title", "author"]
help_texts = {
"title": "The title of the book",
"author": "The author of the book",
}
# ... other attributes
Required attributes are :attr:`~ModelFormOptions.model`, and either
:attr:`~ModelFormOptions.fields` or :attr:`~ModelFormOptions.exclude`. All
other ``Meta`` attributes are optional.
Optional attributes, other than :attr:`~ModelFormOptions.localized_fields` and
:attr:`~ModelFormOptions.formfield_callback`, expect a dictionary that maps a
model field name to a value. Any field that is not defined in the dictionary
falls back to the field's default value.
.. admonition:: Invalid field names
Invalid or excluded field names in an optional dictionary attribute have no
effect, since fields that are not included are not accessed.
.. admonition:: Invalid Meta class attributes
You may define any attribute on a ``Meta`` class. Typos or incorrect
attribute names do not raise an error.
``error_messages``
------------------
.. attribute:: ModelFormOptions.error_messages
A dictionary that maps a model field name to a dictionary of error message
keys (``null``, ``blank``, ``invalid``, ``unique``, etc.) mapped to custom
error messages.
When a field is not specified, Django will fall back on the error messages
defined in that model field's :attr:`django.db.models.Field.error_messages`
and then finally on the default error messages for that field type.
``exclude``
-----------
.. attribute:: ModelFormOptions.exclude
A tuple or list of :attr:`~ModelFormOptions.model` field names to be
excluded from the form.
Either :attr:`~ModelFormOptions.fields` or
:attr:`~ModelFormOptions.exclude` must be set. If neither are set, an
:class:`~django.core.exceptions.ImproperlyConfigured` exception will be
raised. If :attr:`~ModelFormOptions.exclude` is set and
:attr:`~ModelFormOptions.fields` is unset, all model fields, except for
those specified in :attr:`~ModelFormOptions.exclude`, are included in the
form.
``field_classes``
-----------------
.. attribute:: ModelFormOptions.field_classes
A dictionary that maps a model field name to a :class:`~django.forms.Field`
class, which overrides the ``form_class`` used in the model field's
:meth:`.Field.formfield` method.
When a field is not specified, Django will fall back on the model field's
:ref:`default field class <model-form-field-types>`.
``fields``
----------
.. attribute:: ModelFormOptions.fields
A tuple or list of :attr:`~ModelFormOptions.model` field names to be
included in the form. The value ``'__all__'`` can be used to specify that
all fields should be included.
If any field is specified in :attr:`~ModelFormOptions.exclude`, this will
not be included in the form despite being specified in
:attr:`~ModelFormOptions.fields`.
Either :attr:`~ModelFormOptions.fields` or
:attr:`~ModelFormOptions.exclude` must be set. If neither are set, an
:class:`~django.core.exceptions.ImproperlyConfigured` exception will be
raised.
``formfield_callback``
----------------------
.. attribute:: ModelFormOptions.formfield_callback
A function or callable that takes a model field and returns a
:class:`django.forms.Field` object.
``help_texts``
--------------
.. attribute:: ModelFormOptions.help_texts
A dictionary that maps a model field name to a help text string.
When a field is not specified, Django will fall back on that model field's
:attr:`~django.db.models.Field.help_text`.
``labels``
----------
.. attribute:: ModelFormOptions.labels
A dictionary that maps a model field names to a label string.
When a field is not specified, Django will fall back on that model field's
:attr:`~django.db.models.Field.verbose_name` and then the field's attribute
name.
``localized_fields``
--------------------
.. attribute:: ModelFormOptions.localized_fields
A tuple or list of :attr:`~ModelFormOptions.model` field names to be
localized. The value ``'__all__'`` can be used to specify that all fields
should be localized.
By default, form fields are not localized, see
:ref:`enabling localization of fields
<modelforms-enabling-localization-of-fields>` for more details.
``model``
---------
.. attribute:: ModelFormOptions.model
Required. The :class:`django.db.models.Model` to be used for the
:class:`~django.forms.ModelForm`.
``widgets``
-----------
.. attribute:: ModelFormOptions.widgets
A dictionary that maps a model field name to a
:class:`django.forms.Widget`.
When a field is not specified, Django will fall back on the default widget
for that particular type of :class:`django.db.models.Field`.
Model form factory functions
============================
.. currentmodule:: django.forms.models
``modelform_factory``
---------------------
.. function:: modelform_factory(model, form=ModelForm, fields=None, exclude=None, formfield_callback=None, widgets=None, localized_fields=None, labels=None, help_texts=None, error_messages=None, field_classes=None)
Returns a :class:`~django.forms.ModelForm` class for the given ``model``.
You can optionally pass a ``form`` argument to use as a starting point for
constructing the ``ModelForm``.
``fields`` is an optional list of field names. If provided, only the named
fields will be included in the returned fields.
``exclude`` is an optional list of field names. If provided, the named
fields will be excluded from the returned fields, even if they are listed
in the ``fields`` argument.
``formfield_callback`` is a callable that takes a model field and returns
a form field.
``widgets`` is a dictionary of model field names mapped to a widget.
``localized_fields`` is a list of names of fields which should be
localized.
``labels`` is a dictionary of model field names mapped to a label.
``help_texts`` is a dictionary of model field names mapped to a help text.
``error_messages`` is a dictionary of model field names mapped to a
dictionary of error messages.
``field_classes`` is a dictionary of model field names mapped to a form
field class.
See :ref:`modelforms-factory` for example usage.
You must provide the list of fields explicitly, either via keyword
arguments ``fields`` or ``exclude``, or the corresponding attributes on the
form's inner ``Meta`` class. See :ref:`modelforms-selecting-fields` for
more information. Omitting any definition of the fields to use will result
in an :exc:`~django.core.exceptions.ImproperlyConfigured` exception.
``modelformset_factory``
------------------------
.. function:: modelformset_factory(model, form=ModelForm, formfield_callback=None, formset=BaseModelFormSet, extra=1, can_delete=False, can_order=False, max_num=None, fields=None, exclude=None, widgets=None, validate_max=False, localized_fields=None, labels=None, help_texts=None, error_messages=None, min_num=None, validate_min=False, field_classes=None, absolute_max=None, can_delete_extra=True, renderer=None, edit_only=False)
Returns a ``FormSet`` class for the given ``model`` class.
Arguments ``model``, ``form``, ``fields``, ``exclude``,
``formfield_callback``, ``widgets``, ``localized_fields``, ``labels``,
``help_texts``, ``error_messages``, and ``field_classes`` are all passed
through to :func:`~django.forms.models.modelform_factory`.
Arguments ``formset``, ``extra``, ``can_delete``, ``can_order``,
``max_num``, ``validate_max``, ``min_num``, ``validate_min``,
``absolute_max``, ``can_delete_extra``, and ``renderer`` are passed
through to :func:`~django.forms.formsets.formset_factory`. See
:doc:`formsets </topics/forms/formsets>` for details.
The ``edit_only`` argument allows :ref:`preventing new objects creation
<model-formsets-edit-only>`.
See :ref:`model-formsets` for example usage.
``inlineformset_factory``
-------------------------
.. function:: inlineformset_factory(parent_model, model, form=ModelForm, formset=BaseInlineFormSet, fk_name=None, fields=None, exclude=None, extra=3, can_order=False, can_delete=True, max_num=None, formfield_callback=None, widgets=None, validate_max=False, localized_fields=None, labels=None, help_texts=None, error_messages=None, min_num=None, validate_min=False, field_classes=None, absolute_max=None, can_delete_extra=True, renderer=None, edit_only=False)
Returns an ``InlineFormSet`` using :func:`modelformset_factory` with
defaults of ``formset=``:class:`~django.forms.models.BaseInlineFormSet`,
``can_delete=True``, and ``extra=3``.
If your model has more than one :class:`~django.db.models.ForeignKey` to
the ``parent_model``, you must specify a ``fk_name``.
See :ref:`inline-formsets` for example usage.