MultiValueField

Aggregate the logic of multiple Fields.

Attributes

Attribute	Type	Description
default_error_messages	dict = {'invalid': 'Enter a list of values.', 'incomplete': 'Enter a complete value.'}	A dictionary of error message templates used to provide feedback for invalid or incomplete input data.

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Constructor

Signature

def MultiValueField(
    fields: list,
    require_all_fields: boolean = True,
    **kwargs: dict
) - > null

Parameters

Name	Type	Description
fields	list	A list or tuple of Field instances that compose this MultiValueField.
require_all_fields	boolean = True	If True, validation fails if any individual field is empty. If False, individual field requirements are respected.
**kwargs	dict	Additional keyword arguments passed to the parent Field class constructor.

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Methods

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validate()

@classmethod
def validate(
    value: any
) - > null

Performs additional validation on the compressed value; this implementation is a placeholder for subclass overrides.

Parameters

Name	Type	Description
value	any	The single compressed value produced after cleaning all individual sub-fields.

Returns

Type	Description
null	Nothing is returned.

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clean()

@classmethod
def clean(
    value: list
) - > any

Validate every value in the given list. A value is validated against the corresponding Field in self.fields.

Parameters

Name	Type	Description
value	list	A list or tuple of values where each element corresponds to a specific sub-field in the MultiValueField.

Returns

Type	Description
any	The single compressed value resulting from the combined and validated input list.

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compress()

@classmethod
def compress(
    data_list: list
) - > any

Return a single value for the given list of values. The values can be assumed to be valid.

Parameters

Name	Type	Description
data_list	list	A list of cleaned and validated values from the individual sub-fields.

Returns

Type	Description
any	A single combined value, such as a datetime object created from separate date and time inputs.

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has_changed()

@classmethod
def has_changed(
    initial: any,
    data: list
) - > boolean

Determines if the current input data differs from the initial value by comparing each sub-field individually.

Parameters

Name	Type	Description
initial	any	The original value of the field, which may be a single object or a list of values.
data	list	The current submitted data to be compared against the initial state.

Returns

Type	Description
boolean	True if any sub-field value has changed compared to its initial state, False otherwise.

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