title: Conditional (if, else) in Angular 2
body: <p>I worked a few years in .NET, Silverlight now I'm starting with Angular 2 and Expressjs.
  And I have a doubt that even I could not find how can I do this in angular 2 + Expressjs, and is safe from client side?</p>
  
  <pre><code>&lt;% if(User.Identity.IsAuthenticated){ %&gt;
       &lt;b&gt;Sign Out&lt;/b&gt;
  &lt;% } else { %&gt;
       &lt;b&gt;Sign In&lt;/b&gt;
  &lt;% } %&gt;
  </code></pre>