title: Bind a css class name to a viewmodel with knockoutjs
body: <p>I am doing this css binding:</p>
  
  <pre><code>css: { greenBorder: hasGreenBorder, whiteBorder: hasWhiteBorder, blackBorder: hasBlackBorder }
  </code></pre>
  
  <p>This works but why should my viewmodel return not just the css class name like .whiteBorder or .blackBorder.</p>
  
  <p>because my logic is that from all 3 has-Variables there can only be one true the others are always false.</p>
  
  <p>I think there must be a better way just to apply the class name and put this logic which classname to choose in my viewmodel, right?</p>