Google Linechart Visualization Chart Disappears When Updating It?

I want to be able to update the line chart of google visualizations. My code was inspired by this Stack Overflow post. Here is my code in question: http://jsfiddle.net/YCqyG/5/ You

Solution 1:

There seem to be a few issues around the usage of jQuery selectors in your code; it's somewhat confusing around the sections where you're calling $(element) and $(element)[0] etc. In general I'd avoid jQuery here, the refresh works by replacing both of:

• add('LineChart', '#mileage') with add('LineChart', 'mileage')
• $(element)[0] with document.getElementById(element)

Some general advice here:

• You don't need to clear out the div before re-rendering a chart (i.e.: No need to call this.element.html(''), simple passing in a new data table and re-calling .draw(newDataTable, opts) is fine. Whilst potentially beyond the needs of this post, the new gviz animation functionality is a good example of this (you just call redraw with updated data, and the graph animates the change).

• Obviously I'm unaware of the full need of your implementation, but I feel like your code may be slightly more involved than you need. Depending on how you get can data sent from your server, you can pretty easily reload a chart. I've given some details in this question, but in brief it looks like this:

  functiondrawMyChart(dataTable) {
      // convert your dataTable to the right format// options here include loading from arrays, json representations of your datatable// or something more manual perhapsvar opts = {height:50, width:50};
      var chart = new google.visualization.LineChart(document.getElementById('vis'));
      chart.draw(dataTable, opts);
  }
  
  functionmakeAjaxCall() {
      $.ajax({
          url: '/path/to/data/json',
          sucess: drawMyChart(a),
          dataType: 'json'// this is important, have it interpreted as json
      });
  }
  // html somewhere
  <div id='vis'></div>
  <inputtype='button'onclick='makeAjaxCall()'>Go</input>

Hope that helps.