PatternValidator

directive

A directive that adds regex pattern validation to controls marked with the pattern attribute. The regex must match the entire control value. The directive is provided with the NG_VALIDATORS multi-provider list.

See also

NgModules

Selectors

Properties

Property Description
@Input()pattern: string | RegExp

Tracks changes to the pattern bound to this directive.

Description

Adding a pattern validator

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

<input name="firstName" ngModel pattern="[a-zA-Z ]*">

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 matches the the pattern requirement.

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://v7.angular.io/api/forms/PatternValidator