title: How can I tell if an element reference does exist in blazor
body: <p>If an element is hidden in first render (for example the element is in an if statement scope which has evaluated as false, so won't get rendered), and some event makes it appear (if statement evaluate as true) the inner element reference gets updated after render. This works absolutely fine.</p>
  <p>But in case the opposite event flow (first is true, than gets hidden by some event), the element reference does not get updated after render, still shows the original id instead of null or empty string. In this case if I call JsInterop with that element reference, it would give an error that element does not exists (which is obviously true). The problem is that the element reference still has the former id, it didn't get changed after render.</p>
  <p>The question is how can I tell if an element is visible (rendered, existing) or not?</p>