@angular/forms

MaxLengthValidator

directive

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

API

  
    class MaxLengthValidator extends AbstractValidatorDirective {}

maxlength

string | number | null

Tracks changes to the maximum length bound to this directive.

ngOnChanges

void

@paramchangesSimpleChanges

@returnsvoid

validate

ValidationErrors | null

@paramcontrolAbstractControl<any, any>

@returnsValidationErrors | null

registerOnValidatorChange

void

@paramfn() => void

@returnsvoid

enabled

boolean

Determines whether this validator should be active or not based on an input. Base class implementation checks whether an input is defined (if the value is different from null and undefined). Validator classes that extend this base class can override this function with the logic specific to a particular validator directive.

@paraminputunknown

@returnsboolean

Description

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

Exported by

Usage Notes

Adding a maximum length validator

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

          <input name="firstName" ngModel maxlength="25">