title: Show No data message when chart has no data
body: <p>I am trying to show no data message when chart has no data.
  Is it correct?</p>
  
  <pre><code>  var ctx = document.getElementById('mycanvas').getContext('2d');
          var chart = new Chart(ctx, {
              type: 'doughnut',
              data: {
                  labels: ["aa", "bb", "cc", "dd"],
                  datasets: [{
                      label: "My First dataset",
                      backgroundColor: ['red', 'blue', 'green', 'yello'],
                      data: data.length ? data: [{ label: "No Data", value: 100 }],
                  }]
              },
              options: {
                  legend: {
                      position: 'right',
                      labels: {
                          boxWidth: 12
                      }
                  },
                  tooltips: { bodyFontSize: 12 }
              }
          });
  </code></pre>
  
  <p>I am not getting No data message when data length is 0.</p>