Angular 4, How to update [(ngModel)] with a delay of 1 seconds : <p>Since ngModel is updating instantly how to put a delay.</p>

<pre><code>  &lt;input type="text" value="{{item.task_name}}" name="task_name" [(ngModel)]="item.task_name" (ngModelChange)="update_fields([item.task_name])" &gt;
</code></pre>

<p>I need to save the task_name with a delay of one seconds by calling update_fields() , To avoid instant calls to service. </p>

<p>Thanks</p>
