title: Angular.js ng-switch ---testing if value is empty or undefined
body: <p>In Angular.js templating, I need to test if a value is undefined or empty.... I am not sure how to do this since <code>ng-switch-when</code> tests for expressions in strings. I needed to use <code>ng-switch</code> because it's a if else condition. Any ideas?</p>
  
  <pre><code>&lt;div ng-switch="vipLabel"&gt;
    &lt;div ng-switch-when="vipLabel.toString()"&gt;
      &lt;h1&gt;Getting infomration...one sec&lt;/h1&gt;
    &lt;/div&gt;
      &lt;div ng-switch-default&gt;
        &lt;h3&gt;Do you wish to unbind {{node.label}} from {{ vipLabel }}?&lt;/h3&gt;
      &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>