title: Calling a class and function using variable
body: <p>I have been wondering if it is possible to call function like this</p>
  
  <pre><code>//
  public function getDataSource($id,$source,Request $request){
  
      $form = 'Invoice';
      $fuToCall = $source;
  
      return \App\Core\Forms\.$form.\.$form.DataSource::$fuToCall();
  
  
  }
  </code></pre>
  
  <p>The concatenation of my $form name doesn't work, why? Can someone please help.</p>