Wykresy todo

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="utf-8" />
  <title>{{ title }}</title>
  <script src='https://cdnjs.cloudflare.com/ajax/libs/Chart.js/1.0.2/Chart.min.js'></script>
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>


</head>

<body>
<h1>{{ title }}</h1>
Wartość a: <br/>
<form>
<input type="text" id="a" /></br>
Wartość b: <br/>
<input type="text" id="b" /></br>
<input type="submit" vale="Oblicz" />
</form>
    <canvas id="chart" width="600" height="400"></canvas>


  <script>
$(function () {
  $('form').on('submit', function (e) {
      e.preventDefault();
      var obj = new Object();
      obj.a = document.getElementById("a").value;
      obj.b  = document.getElementById("b").value;
      var jsonString= JSON.stringify(obj);
    $.post("/data",jsonString,
  function(data, status){
    console.log(Object.getOwnPropertyNames(data));
	addData(LineChartDemo,data);
});
      });
	        });

function addData(chart,jsonData) {
		chart.data = jsonData["a"];
		chart.labels = jsonData.labels;
        chart.update();
}

function removeData(chart) {
  /*  chart.data.labels.pop();
    chart.data.datasets.forEach((dataset) => {
        dataset.data.pop();
    });
    chart.update();*/
}


      Chart.defaults.global.animationSteps = 50;
      Chart.defaults.global.tooltipYPadding = 16;
      Chart.defaults.global.tooltipCornerRadius = 0;
      Chart.defaults.global.tooltipTitleFontStyle = "normal";
      Chart.defaults.global.tooltipFillColor = "rgba(0,0,0,0.8)";
      Chart.defaults.global.animationEasing = "easeOutBounce";
      Chart.defaults.global.responsive = false;
      Chart.defaults.global.scaleLineColor = "black";
      Chart.defaults.global.scaleFontSize = 16;

      // get bar chart canvas
      var mychart = document.getElementById("chart").getContext("2d");

      steps = 10
      // draw bar chart
      var LineChartDemo = new Chart(mychart).Line(barData, {
		data: [0],
		options: {},
        scaleOverride: true,
        scaleSteps: steps,
        scaleStartValue: 0,
        scaleShowVerticalLines: true,
        scaleShowGridLines : true,
        barShowStroke : true,
        scaleShowLabels: true,
        bezierCurve: false,
      });

 </script>

</body>
</html>