最简单的方法来自动刷新页面中嵌入的Google图表

I have two files, one outputting data from a MySQL database and one drawing a Google Graph within a page with other metrics:

grab_twitter_stats.php Output:

[15, 32], [14, 55], [13, 45], [12, 52], [11, 57], [10, 55], [9, 58], [8, 42], [7, 44], [6, 40], [5, 54], [4, 52], [3, 60], [2, 71], [1, 43],

index.php Output:

<div id="curve_chart" style="width: 900px; height: 500px">

<script type="text/javascript">

google.charts.load('current', {packages: ['corechart']});
google.charts.setOnLoadCallback(drawChart);
function drawChart() {
    var data = google.visualization.arrayToDataTable([
      ['Minutes', 'Tweets'],

      <?php require('grab_twitter_stats.php');?>

    ]);

    var options = {
      title: 'Tweets in last 15 Minutes',
      curveType: 'function',
      hAxis: {
      title: 'Last 15 Minutes',
      direction: '-1'
      },
      legend: { position: 'bottom' }

    };

    var chart = new google.visualization.LineChart(document.getElementById('curve_chart'));

    chart.draw(data, options);

}

</script>   
</div>

This draws a graph that shows tweets in the last 15 minutes. I can get the graph to appear once, but upon trying to load a SetInterval, it does not refresh the Google Graph on the interval. I have tried wrapping the entire drawChart() function in it, and it doesn't seem to be working. I tried using AJAX but it is not formatted in JSON so ajax doesn't like it. Any suggestions on the easiest way to make this graph auto refresh?

although not JSON, you can still use ajax, even with plain text

something like this should get you close...

google.charts.load('current', {
  callback: function () {
    drawChart();
    setInterval(drawChart, (15 * 60 * 1000));

    function drawChart() {
      $.ajax({
        url: 'grab_twitter_stats.php',
        type: 'get',
        success: function (txt) {
          // check for trailing comma
          if (txt.slice(-1) === ',') {
            txt = txt.substring(0, txt.length - 1);
          }
          var txtData = JSON.parse('[["Minutes", "Tweets"],' + txt + ']');

          var data = google.visualization.arrayToDataTable(txtData);

          var options = {
            title: 'Tweets in last 15 Minutes',
            curveType: 'function',
            hAxis: {
              title: 'Last 15 Minutes',
              direction: '-1'
            },
            legend: { position: 'bottom' }
          };

          var chart = new google.visualization.LineChart(document.getElementById('curve_chart'));
          chart.draw(data, options);
        }
      });
    }
  },
  packages: ['corechart']
});