Class Charts

function doGet() {
  var data = Charts.newDataTable()
      .addColumn(Charts.ColumnType.STRING, "Month")
      .addColumn(Charts.ColumnType.NUMBER, "In Store")
      .addColumn(Charts.ColumnType.NUMBER, "Online")
      .addRow(["January", 10, 1])
      .addRow(["February", 12, 1])
      .addRow(["March", 20, 2])
      .addRow(["April", 25, 3])
      .addRow(["May", 30, 4])
      .build();

  var chart = Charts.newAreaChart()
      .setDataTable(data)
      .setStacked()
      .setRange(0, 40)
      .setTitle("Sales per Month")
      .build();

   var htmlOutput = HtmlService.createHtmlOutput().setTitle('My Chart');
   var imageData = Utilities.base64Encode(chart.getAs('image/png').getBytes());
   var imageUrl = "data:image/png;base64," + encodeURI(imageData);
   htmlOutput.append("Render chart server side: <br/>");
   htmlOutput.append("<img border=\"1\" src=\"" + imageUrl + "\">");
   return htmlOutput;
}