# Τεκμηρίωση του Django - 6.0.7

# Model forms

`ModelForm` API reference. For introductory material about using a `ModelForm`, see the Creating forms from models 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 a `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 `model`, and either `fields` or `exclude`. All other `Meta` attributes are optional.

Optional attributes, other than `localized_fields` and `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.

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.

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`

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 `django.db.models.Field.error_messages` and then finally on the default error messages for that field type.

### `exclude`

ModelFormOptions.exclude

  A tuple or list of `model` field names to be excluded from the form.

  Either `fields` or `exclude` must be set. If neither are set, an `ImproperlyConfigured` exception will be raised. If `exclude` is set and `fields` is unset, all model fields, except for those specified in `exclude`, are included in the form.

### `field_classes`

ModelFormOptions.field_classes

  A dictionary that maps a model field name to a `Field` class, which overrides the `form_class` used in the model field’s `Field.formfield()` method.

  When a field is not specified, Django will fall back on the model field’s default field class.

### `fields`

ModelFormOptions.fields

  A tuple or list of `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 `exclude`, this will not be included in the form despite being specified in `fields`.

  Either `fields` or `exclude` must be set. If neither are set, an `ImproperlyConfigured` exception will be raised.

### `formfield_callback`

ModelFormOptions.formfield_callback

  A function or callable that takes a model field and returns a `django.forms.Field` object.

### `help_texts`

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 `help_text`.

### `labels`

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 `verbose_name` and then the field’s attribute name.

### `localized_fields`

ModelFormOptions.localized_fields

  A tuple or list of `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 enabling localization of fields for more details.

### `model`

ModelFormOptions.model

  Required. The `django.db.models.Model` to be used for the `ModelForm`.

### `widgets`

ModelFormOptions.widgets

  A dictionary that maps a model field name to a `django.forms.Widget`.

  When a field is not specified, Django will fall back on the default widget for that particular type of `django.db.models.Field`.

## Model form factory functions

### `modelform_factory`

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 `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 ModelForm factory function 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 Selecting the fields to use for more information. Omitting any definition of the fields to use will result in an `ImproperlyConfigured` exception.

### `modelformset_factory`

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 `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 `formset_factory()`. See formsets for details.

  The `edit_only` argument allows preventing new objects creation.

  See Model formsets for example usage.

### `inlineformset_factory`

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 `modelformset_factory()` with defaults of `formset=``BaseInlineFormSet`, `can_delete=True`, and `extra=3`.

  If your model has more than one `ForeignKey` to the `parent_model`, you must specify a `fk_name`.

  See Inline formsets for example usage.