src/app/common/forms/form.component.ts

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 {AbstractControl, FormGroup} from '@angular/forms';

export abstract class FormComponent<T> {

  form: FormGroup;

  constructor() {
    this.form = new FormGroup({});
  }

  abstract get formData(): T

  abstract set formData(data: T)

  get pristine(): boolean {
    if (!this.form) {
      return true;
    }
    return this.form.pristine;
  }

  get valid(): boolean {
    if (!this.form) {
      return true;
    }
    return this.form.valid;
  }

  get dirty(): boolean {
    if (!this.form) {
      return true;
    }
    return this.form.dirty;
  }

  /**
   * Checks if form is pristine before doing valid check
   * @returns {boolean}
   */
  get validWhenOptional(): boolean {
    if (!this.pristine && this.valid) {
      return true;
    }else if (!this.pristine && !this.valid) {
      return false;
    }
    return true;
  }

  setError(field: string, error: string, value: any): void {
    const control: AbstractControl = this.form.get(field);
    const errors = control.errors || {};
    errors[error] = value;
    control.setErrors(errors);
  }
}