src/app/common-components/pipes/unique.pipe.ts

/*
******************************************************************************
* Copyright © 2018 PTA GmbH.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
*
*     http://www.eclipse.org/legal/epl-v10.html
*
******************************************************************************
*/

import { Pipe, PipeTransform } from '@angular/core';

@Pipe({
  name: 'unique'
})
export class UniquePipe implements PipeTransform {

  transform(items: any[], fieldName: string): any[] {
    const cArray = [];
    if (!items) {
      return [];
    }
    return items.filter((item, index, arr) => {
      const itemExists = cArray.find(ia => {
        return ia === item[fieldName];
      }
      );
      if ((item[fieldName] || item[fieldName] === 0) && !itemExists && itemExists !== 0) {
        cArray.push(item[fieldName]);
        return true;
      } else {
        return false;
      }
    });
  }
}