title: Refreshing chart Ionic 2 Chart.js
body: <p>I need to update a a doughnut chart when navagating back to a component but as it is at the moment it is not. </p>
  
  <pre><code>renderChart(oplTitle, oplScore, oplScoreDifference) {
   this.options = {
    type: 'doughnut',
    data: {
      labels: ["Opl progress", ""],
      datasets: [{
        borderWidth: 0,
        data: [oplScore, oplScoreDifference],
        backgroundColor: [
          'rgba(250, 203, 27, 0.9)',
          'rgba(255, 255, 255, 1)'
        ],
        borderColor: [
          'rgba(250, 203, 27, 1)',
          'rgba(250, 203, 27, 1)'
        ],
      }]
    },
    options: {
      responsive: true,
      title: {
        display: true,
        text: oplTitle,
        position: 'bottom'
      },
      tooltips: {
        enabled: false,
        backgroundColor: 'rgba(250, 203, 27, 1)'
      },
      legend: {
        display: false,
        labels: {
          boxWidth: 20
        }
      }
    }
    }
    }
  </code></pre>
  
  <p>I call renderChart when page loads</p>
  
  <pre><code> ionViewDidLoad() {
      this.renderChart(this.title, this.score, this.difference);
   }
  </code></pre>
  
  <p>In the Html </p>
  
  <pre><code>&lt;chart [options]="options"&gt;&lt;/chart&gt;
  </code></pre>
  
  <p>As it is at the moment the chart renders but when navigating away and values get updated, it doesnt refresh when returning to the page. How can I 'refresh' </p>