tasks.html

    <ion-list>
      <ion-item-sliding *ngFor="let item of items; let idx = index;">
        <button ion-item>
          <h2>{{item.category}}</h2>
          <p>{{item.description}}</p>
        </button>

        <ion-item-options>
          <button ion-button color="danger" (click)="deleteTask(item, idx)">DELETE</button>
        </ion-item-options>
      </ion-item-sliding>
    </ion-list>