如何使Google Chart响应导航标签

<script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"></script>

google.charts.load('current', {packages: ['corechart', 'bar', 'pie']});

<ul id="chartTabs">
  <li data-chart="bar">柱状图</li>
  <li data-chart="pie">饼图</li>
</ul>

document.getElementById('chartTabs').addEventListener('click', function(event) {
  var chartType = event.target.getAttribute('data-chart');
  drawChart(chartType);
});

function drawChart(chartType) {
  var data = google.visualization.arrayToDataTable([
    ['Task', 'Hours per Day'],
    ['Work', 8],
    ['Sleep', 8],
    ['Eat', 2],
    ['Exercise', 2],
    ['Relax', 4]
  ]);

  var options = {
    title: 'My Daily Activities'
  };

  var chart;
  if (chartType === 'bar') {
    chart = new google.visualization.BarChart(document.getElementById('chartContainer'));
  } else if (chartType === 'pie') {
    chart = new google.visualization.PieChart(document.getElementById('chartContainer'));
  }

  chart.draw(data, options);
}

<div id="chartContainer"></div>