title: Angular Two-Way Data Binding and Watching for Changes in Parent Component
body: <p>It seems there is no way to watch changes in the parent component when using two-way data binding.</p>
  <p>I have a custom input component for collecting a tag list. Two-way data binding is setup and working between this component and its parent.</p>
  <pre class="lang-html prettyprint-override"><code>// the parent component is just a form
  // here is how I'm adding the child component
  &lt;input-tags formControlName=&quot;skillField&quot; [(tags)]='skillTags' (ngModelChange)=&quot;skillTagUpdate($event)&quot;&gt;
  &lt;/input-tags&gt;
  </code></pre>
  <p>In the parent component how do you watch the bound variable for changes? While it's always up to date (I've confirmed this) I cannot find any guidance on reacting to changes.</p>
  <p>I've tried:</p>
  <pre class="lang-js prettyprint-override"><code>ngOnChanges(changes: SimpleChanges) {
      if (changes['skillTags']) {
          console.log(this.skillTags);  // nothing
      }
  }
  </code></pre>
  <p>And</p>
  <pre class="lang-js prettyprint-override"><code>skillTagUpdate(event){
      console.log(event); // nothing
  }
  </code></pre>
  <p><strong>UPDATE:</strong>
  TWDB IMHO is not what it is advertised to be. Whenever I arrive at this place where TWDB seems to be a solution I rearchitect for a service and or observable communication instead.</p>