title: Overriding units on a jQuery Knob does not redraw correctly on page reload
body: <p>I have a readonly jQuery Knob. I have been able to add units to the numeric display (as per <a href="https://stackoverflow.com/questions/18955708/how-to-display-units-with-jquery-knob">How to display units with Jquery Knob</a> ), but the foreground (ie. graphical value indicator) of the dial is no longer displayed when the page is reloaded.</p>
  
  <p>Here's my HTML:</p>
  
  <pre><code>&lt;input class="knob" id="workload" data-angleoffset=-125 data-anglearc=250 value="{{ workload }}" &gt;
  </code></pre>
  
  <p>( <code>{{ workload }}</code> is a floating point Django template value - it is being substituted correctly )</p>
  
  <p>Inside my jQuery ready function, I have:</p>
  
  <pre><code>if (jQuery().knob &amp;&amp; ! App.isIE8()) {
  
      // Workload Indicator
      $(".knob").knob({
          'dynamicDraw': true,
          'min': 0, 'max':100,
          'thickness': 0.2,
          'tickColorizeValues': true,
          'readOnly': true,
          'skin': 'tron',
          'fgColor': '#F00', 
          'inputColor':'#3D3D3D',
          'bgColor': '#3D3D3D',
          'width' : 150,
          'draw' : function () {
              $(this.i).val( parseInt(this.cv) + '%');
          }
      });
  }
  </code></pre>
  
  <p><code>fgColor</code> was originally set from the template value, but the above code with a hard-coded <code>fgColor</code> produces the same result.</p>
  
  <p>Commenting out the <code>draw</code> callback works as expected: The knob is drawn complete with a numeric value in the middle and a red colored indicator on the outside arc.
  Uncommenting the <code>draw</code> fixes the numeric formatting (no decimal points + a percentage sign).  The numeric formatting remains correct for initial display and on re-load.
  However the red arc only appears on the initial display - it disappears when the page is re-loaded!</p>
  
  <p>So what is going on? Is <code>draw</code> over-riding jquery-knob's own canvas draw method? If so, how can I call the graphical draw part?</p>