src/app/shared/components/error/error.component.ts

/********************************************************************************
 * Copyright © 2018 Mettenmeier GmbH.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * SPDX-License-Identifier: EPL-2.0
 ********************************************************************************/
import { Component, OnInit, Input } from '@angular/core';
import { AbstractControlDirective, AbstractControl } from '@angular/forms';

@Component({
  selector: 'ok-error',
  templateUrl: './error.component.html',
  styleUrls: ['./error.component.scss']
})
export class ErrorComponent implements OnInit {
  private static readonly errorMessages = {
    'required': () => 'Dieses Feld muss ausgefüllt werden.',
    'minlength': (params) => `Es müssen mindestens ${params.requiredLength} Zeichen eingegeben werden`,
    'maxlength': (params) => `Es dürfen maximal ${params.requiredLength} Zeichen eingegeben werden`,
    'pattern': (params) => `Die Eingabe entspricht nicht dem Muster: ${params.requiredPattern}`,
    'invalidDate': () => `Das "von"-Datum muss vor dem "bis"-Datum liegen.`
  };

  @Input()
  private control: AbstractControlDirective | AbstractControl;

  constructor() { }

  ngOnInit() {
  }

  shouldShowErrors(): boolean {
    return this.control &&
      this.control.errors &&
      (this.control.dirty || this.control.touched);
  }

  listOfErrors(): string[] {
    if (!this.control.errors) {
      return [];
    }
    return Object.keys(this.control.errors)
      .map(field => this.getMessage(field, this.control.errors[field]));
  }

  private getMessage(type: string, params: any) {
    if (type in ErrorComponent.errorMessages) {
      return ErrorComponent.errorMessages[type](params);
    }
    return '';
  }

}