title: How to pass a class name in angular from component.ts to html SVG
body: <p>I'm using d3 to create charts and every chart has to have a unique id.</p>
  
  <p>so I need to use something like:</p>
  
  <p><code>&lt;svg class="{{className}}"&gt;&lt;/svg&gt;</code></p>
  
  <p>className is defined in component.ts
  but this isn't working </p>
  
  <p>it works when I hard code the value, but when I pass in the class name in the value it doesn't work</p>