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MinLengthValidator

directive

A directive that adds minimum length validation to controls marked with the minlength attribute. The directive is provided with the NG_VALIDATORS mult-provider list.

See also

NgModules

Selectors

Properties

Property Description
@Input()minlength: string

Tracks changes to the the minimum length bound to this directive.

Description

Adding a minimum length validator

The following example shows how to add a minimum length validator to an input attached to an ngModel binding.

<input name="firstName" ngModel minlength="4">

Methods

A lifecycle method called when the directive's inputs change. For internal use only.

ngOnChanges(changes: SimpleChanges): void

Parameters
changes SimpleChanges

A object of key/value pairs for the set of changed inputs.

Returns

void

Method that validates whether the value meets a minimum length requirement. Returns the validation result if enabled, otherwise null.

validate(control: AbstractControl): ValidationErrors | null

Parameters
control AbstractControl
Returns

ValidationErrors | null

Registers a callback function to call when the validator inputs change.

registerOnValidatorChange(fn: () => void): void

Parameters
fn () => void

The callback function

Returns

void

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Licensed under the Creative Commons Attribution License 4.0.
https://angular.io/api/forms/MinLengthValidator