MinLengthValidator

From Get docs
< @angular/formsAngular/docs/9/api/forms/minlengthvalidator


MinLengthValidator

directive

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

See also

NgModules

Selectors

  • [minlength][formControlName]
  • [minlength][formControl]
  • [minlength][ngModel]

Properties

Property Description
number 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://v9.angular.io/api/forms/MinLengthValidator