title: Angular + Google charts : ng-model not updating
body: <p>I have a simple google chart and embedded with Angular. The chart gets displayed, implies im able to bind data from angular to googlechart. However the problem is, if i edit a value in array (chart data source) chart is not getting updated.</p>
  
  <p>Code :</p>
  
  <pre><code>&lt;html&gt;
  &lt;head&gt;
      &lt;!--Load the AJAX API--&gt;
      &lt;script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"&gt;&lt;/script&gt;
      &lt;script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.5.0/angular.js"&gt;&lt;/script&gt;
  
      &lt;script type="text/javascript"&gt;
          var myApp = angular.module("myApp", []);
          myApp.controller("myCnt", function ($scope) {
              $scope.dataArray = [
                ['Mushrooms', 3],
                ['Onions', 1],
                ['Olives', 1],
                ['Zucchini', 1],
                ['Pepperoni', 2]
              ];
  
              google.charts.load('current', { packages: ['corechart'] });
              google.charts.setOnLoadCallback(drawChart);
  
              function drawChart() {
                  var data = new google.visualization.DataTable();
                  data.addColumn('string', 'Topping');
                  data.addColumn('number', 'Slices');
                  data.addRows($scope.dataArray);
  
                  // Set chart options
                  var options = {
                      'title': 'How Much Pizza I Ate Last Night',
                      'width': 400,
                      'height': 300
                  };
  
                  // Instantiate and draw our chart, passing in some options.
                  var chart = new google.visualization.PieChart(document.getElementById('chart_div'));
                  chart.draw(data, options);
              }
          });
      &lt;/script&gt;
  &lt;/head&gt;
  
  &lt;body ng-app="myApp" ng-controller="myCnt"&gt;
      &lt;input type="text" ng-model="dataArray[0][1]" /&gt;&lt;br /&gt;
      &lt;span ng-bind="dataArray[0][1]"&gt;&lt;/span&gt;
      &lt;div id="chart_div"&gt;&lt;/div&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p><strong>Edit 1:</strong>
  Values of first array are edited through a text box in HTML. Im sure the edit is reflecting, as i can see the span element displaying updated value. Somehow the same value is not getting bind to the chart.</p>
  
  <p>Do i need to load the chart again by calling chart.draw(data, options); If yes, then where should i be calling?</p>
  
  <p>Thank you</p>