/**
 * 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 {ControlValueAccessor} from '@angular/forms';

const noop: any = () => {
  // empty method
};

export abstract class AbstractControlValueAccessor implements ControlValueAccessor {

  protected _value: any = undefined;

  get value(): any { return this._value; }

  set value(v: any) {
    if (v !== this._value) {
      this._value = v;
      this.onChange(v);
    }
  }

  writeValue(value: any): void {
    this.value = value;
  }

  registerOnChange(fn: any): void {
    this.onChange = fn;
  }

  registerOnTouched(fn: any): void {
    this.onTouched = fn;
  }

  onChange = (_: any) => noop;
  onTouched = () => noop;
}