title: How can I pass a dynamic value to matIcon?
body: <p>Just trying to pass a string into component input so I can have a dynamic icon. Is this possible? <a href="https://stackblitz.com/edit/angular-xtes4d?file=app%2Falert.component.ts" rel="noreferrer">Stackblitz demo</a></p>
  
  <pre class="lang-ts prettyprint-override"><code>@Component({
    selector: 'app-alert',
    template: `
      &lt;mat-icon class="alert--{{context}}" *ngIf="icon"&gt;{{icon}}&lt;/mat-icon&gt;
    `,
  })
  export class AlertComponent implements OnInit {
    @Input() context: string;
  
    @Input() icon: string;
  
    @Input() message: string;
  
    constructor() {}
  
    ngOnInit() {}
  }
  </code></pre>
  
  <pre class="lang-html prettyprint-override"><code>&lt;mat-icon&gt;home&lt;/mat-icon&gt;
  &lt;app-alert [context]="'primary'" [icon]="'check'" [message]="'blah message working'"&gt;&lt;/app-alert&gt;
  </code></pre>