title: Animate a bezier path drawn in drawRect() Swift
body: <p>I have this shape that i draw in <code>drawRect()</code></p>
  
  <pre><code>var rectanglePath = UIBezierPath()
  
  override func drawRect(rect: CGRect) {
      rectanglePath = UIBezierPath(rect: self.bounds)
      rectanglePath.fillWithBlendMode(kCGBlendModeMultiply, alpha: 0.7)
      layer.shouldRasterize = true
  }
  </code></pre>
  
  <p>When <code>prepareForEditing</code> function is called, i want to animate the rectanglePath. I tried</p>
  
  <pre><code>  func prepareForEditing(editing:Bool){
          UIView.animateWithDuration(0.5,
              animations: {
                self.rectanglePath = makeNewShape()
              }
         )
    }
  </code></pre>
  
  <p>Nothing happens. Can you please tell me what's wrong with my code?</p>