error-state-matcher.ts

/*
 *    Copyright 2018 OICR
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 */
import { UntypedFormControl, FormGroupDirective, NgForm } from '@angular/forms';
import { ErrorStateMatcher } from '@angular/material/core';

/** Error when invalid control is dirty, touched, or submitted. */
export class MyErrorStateMatcher implements ErrorStateMatcher {
  isErrorState(control: UntypedFormControl | null, form: FormGroupDirective | NgForm | null): boolean {
    const isSubmitted = form && form.submitted;
    return !!(control && control.invalid && (control.dirty || control.touched || isSubmitted));
  }
}