Dont work TypeError: t is null

[einaranjo]

this is my code

function createChart(campo, prefix, initial_value) {
  var input_chart = document.createElement("CANVAS");
  input_chart.id="myChart";
  var ctx = input_chart.getContext('2d');
  var myChart = new Chart(ctx, {
    type: 'bar',
    data: {
        labels: ['Red', 'Blue', 'Yellow', 'Green', 'Purple', 'Orange'],
        datasets: [{
            label: '# of Votes',
            data: [12, 19, 3, 5, 2, 3],
            backgroundColor: [
                'rgba(255, 99, 132, 0.2)',
                'rgba(54, 162, 235, 0.2)',
                'rgba(255, 206, 86, 0.2)',
                'rgba(75, 192, 192, 0.2)',
                'rgba(153, 102, 255, 0.2)',
                'rgba(255, 159, 64, 0.2)'
            ],
            borderColor: [
                'rgba(255, 99, 132, 1)',
                'rgba(54, 162, 235, 1)',
                'rgba(255, 206, 86, 1)',
                'rgba(75, 192, 192, 1)',
                'rgba(153, 102, 255, 1)',
                'rgba(255, 159, 64, 1)'
            ],
            borderWidth: 1
        }]
    },
    options: {
        scales: {
            y: {
                beginAtZero: true
            }
        }
    }
});

  return input_chart;
}

[LeeLenaleee]

Cant seem to reproduce, only thing that seems to happen is a white screen with your code but no error, switching var ctx = input_chart.getContext('2d'); to const ctx = document.getElementById("myChart").getContext('2d') makes it work perfectly fine

Fiddle https://jsfiddle.net/Leelenaleee/2mr53x19/10/

[einaranjo]

For testing purposes, make the following changes.

var input_chart = document.createElement ("CANVAS");
input_chart.id = "myChart";
document.body.appendChild (input_chart);
const ctx = input_chart.getContext ('2d');

It seems that it is necessary that the CANVAS belongs to the DOM in order to perform the rendering.

Thank you
@LeeLenaleee