BaseModelForm

This class provides the base functionality for creating forms that are tied to a specific database model. It handles the mapping of model fields to form fields, manages model instance creation or updates, and integrates model-level validation and constraints into the form's validation lifecycle. Key features include the ability to save the form data directly back to the model instance and support for deferred many-to-many relationship saving.

Attributes

Attribute	Type	Description
instance	[Model](../../db/models/base/model.md?sid=django_db_models_base_model)	The model instance associated with this form, used to populate initial data and receive updated values upon validation.
_validate_unique	boolean = False	A boolean flag that determines whether the model instance's unique constraints should be validated during the cleaning process.
_validate_constraints	boolean = False	A boolean flag that determines whether the model instance's functional constraints should be validated during the cleaning process.

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Constructor

Signature

def BaseModelForm(
    data: Any = None,
    files: Any = None,
    auto_id: str = id_%s,
    prefix: str = None,
    initial: dict = None,
    error_class: type = ErrorList,
    label_suffix: str = None,
    empty_permitted: bool = False,
    instance: [Model](../../db/models/base/model.md?sid=django_db_models_base_model) = None,
    use_required_attribute: bool = None,
    renderer: Any = None
) - > null

Parameters

Name	Type	Description
data	Any = None	The data to be bound to the form.
files	Any = None	The file data to be bound to the form.
auto_id	str = id_%s	The format string used to generate HTML ID attributes.
prefix	str = None	A prefix to be prepended to all form field names.
initial	dict = None	A dictionary of initial values for the form fields.
error_class	type = ErrorList	The class used to display form errors.
label_suffix	str = None	A suffix to be appended to all form labels.
empty_permitted	bool = False	Whether the form is allowed to be empty.
instance	[Model](../../db/models/base/model.md?sid=django_db_models_base_model) = None	The model instance to be associated with the form.
use_required_attribute	bool = None	Whether to use the 'required' HTML attribute on inputs.
renderer	Any = None	The renderer to use for form rendering.

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Methods

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clean()

@classmethod
def clean() - > dict

Sets flags to trigger model uniqueness and constraint validation and returns the cleaned data dictionary.

Returns

Type	Description
dict	The dictionary of validated form data

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validate_unique()

@classmethod
def validate_unique()

Call the instance's validate_unique() method and update the form's validation errors if any were raised.

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validate_constraints()

@classmethod
def validate_constraints()

Call the instance's validate_constraints() method and update the form's validation errors if any were raised.

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save()

@classmethod
def save(
    commit: boolean = True
) - > [Model](../../db/models/base/model.md?sid=django_db_models_base_model)

Save this form's self.instance object if commit=True. Otherwise, add a save_m2m() method to the form which can be called after the instance is saved manually at a later time. Return the model instance.

Parameters

Name	Type	Description
commit	boolean = True	Determines whether the instance is persisted to the database immediately

Returns

Type	Description
[Model](../../db/models/base/model.md?sid=django_db_models_base_model)	The model instance created or updated by the form

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