Converting JSON data for google chart datatable

Question

I am trying to convert this json into the correct format for a google chart:

var jsonData =  {\"Battery Voltage, (A)\":
                    {\"2017-11-11T00:         


        

Answer 1

first, build an array of the column headings...

// build chart columns
var chartCols = ['Datetime'];
Object.keys(jsonData).forEach(function (column) {
  chartCols.push(column);
});

then a unique list of the dates...

// build list of date
var dateValues = [];
Object.keys(jsonData).forEach(function (column) {
  Object.keys(jsonData[column]).forEach(function (dateValue) {
    if (dateValues.indexOf(dateValue) === -1) {
      dateValues.push(dateValue);
    }
  });
});

then you can use each date to find the value in the respective column,
if it exists...

// build chart data
var chartData = [chartCols];
dateValues.forEach(function (dateValue) {
  var row = [new Date(dateValue)];
  Object.keys(jsonData).forEach(function (column) {
    row.push(jsonData[column][dateValue] || null);
  });
  chartData.push(row);
});

google.charts.load('current', {
  packages: ['table']
}).then(function () {
  var jsonData = {
    "Battery Voltage, (A)":
      {"2017-11-11T00:00:00.000Z":12.3
      ,"2017-11-11T00:01:00.000Z":12.35
      ,"2017-11-11T00:02:00.000Z":12.6
      ,"2017-11-11T00:03:00.000Z":12.7
      ,"2017-11-11T00:04:00.000Z":12.8}
    ,"Battery Current, (A)":
      {"2017-11-11T00:00:00.000Z":1.3
      ,"2017-11-11T00:01:00.000Z":1.4
      ,"2017-11-11T00:02:00.000Z":1.5
      ,"2017-11-11T00:03:00.000Z":1.6
      ,"2017-11-11T00:04:00.000Z":1.7}
  };

  // build chart columns
  var chartCols = ['Datetime'];
  Object.keys(jsonData).forEach(function (column) {
    chartCols.push(column);
  });

  // build list of date
  var dateValues = [];
  Object.keys(jsonData).forEach(function (column) {
    Object.keys(jsonData[column]).forEach(function (dateValue) {
      if (dateValues.indexOf(dateValue) === -1) {
        dateValues.push(dateValue);
      }
    });
  });

  // build chart data
  var chartData = [chartCols];
  dateValues.forEach(function (dateValue) {
    var row = [new Date(dateValue)];
    Object.keys(jsonData).forEach(function (column) {
      row.push(jsonData[column][dateValue] || null);
    });
    chartData.push(row);
  });

  var table = new google.visualization.Table(document.getElementById('table_div'));
  table.draw(google.visualization.arrayToDataTable(chartData));
});

<script src="https://www.gstatic.com/charts/loader.js"></script>
<div id="table_div"></div>