title: Angular 7: ngOnChanges fires only once
body: <p>I can't figure out why <strong><code>ngOnChanges</code></strong> only fires once. When initially set.</p>
  
  <pre><code>import { Component, OnInit, Input, SimpleChanges, OnChanges } from '@angular/core';
  
  @Component({
      selector: 'app-fixed-decimals-input',
      templateUrl: './fixed-decimals-input.component.html',
      styleUrls: ['./fixed-decimals-input.component.scss'],
  })
  export class FixedDecimalsInputComponent implements OnInit, OnChanges {
      @Input() value: number;
  
      constructor() {}
  
      ngOnInit() {}
      ngOnChanges(changes: SimpleChanges) {
          console.log(changes);
      }
  }
  
  
  // html file
      &lt;input name="value" [(ngModel)]="value" /&gt;
  </code></pre>
  
  <p>changes to value do not trigger <strong><code>ngOnChanges</code></strong>
  any ideas?</p>