ng2 валидации угловые с использованием реактивныхформ
<form [formGroup]="form">
<input type="password" formControlName="password"/>
<p *ngIf="form.controls.password.errors?.required">required error</p>
<input type="password" formControlName="certainPassword"/>
<p *ngIf="form.controls.certainPassword.errors?.equalTo">equalTo error</p>
</form>
Old-fashioned Orangutan