title: How to add class attribute in angular 2 component typescript file?
body: <p>How to add class attribute in angular 2 component typescript file ?</p>
  
  <p>Below is my footer component code, i want to add <strong>footer</strong> class to it.</p>
  
  <p><strong>footer.component.ts</strong></p>
  
  <pre><code>import { Component } from '@angular/core';
  import { Footer }    from './footer';
  @Component({
    moduleId: module.id,
    selector: 'footer',
    templateUrl: 'footer.component.html'
  })
  export class FooterComponent {
  constructor() {
      this.title = 'Footer Content';
      this.css_class = 'navbar-fixed-bottom';
    }
  }
  </code></pre>
  
  <p><strong>footer.ts</strong></p>
  
  <pre><code>export class Footer {
    constructor(
      public title: string
    ) {  }
  }
  </code></pre>
  
  <p>Please suggest.</p>