ChartJS Line Chart

Multiple Line Chart

by Leelenaleee

HTML

<body>
    <canvas id="chartJSContainer" width="600" height="400"></canvas>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/3.6.0/chart.js"></script>
</body>

CSS

canvas { background-color : #eee;
}

JavaScript

const getOrCreateTooltip = (chart) => {
  let tooltipEl = chart.canvas.parentNode.querySelector('div');

  if (!tooltipEl) {
    tooltipEl = document.createElement('div');
    tooltipEl.style.background = 'rgba(0, 0, 0, 0.7)';
    tooltipEl.style.borderRadius = '3px';
    tooltipEl.style.color = 'white';
    tooltipEl.style.opacity = 1;
    tooltipEl.style.pointerEvents = 'none';
    tooltipEl.style.position = 'absolute';
    tooltipEl.style.transform = 'translate(-50%, 0)';
    tooltipEl.style.transition = 'all .1s ease';

    const table = document.createElement('table');
    table.style.margin = '0px';

    tooltipEl.appendChild(table);
    chart.canvas.parentNode.appendChild(tooltipEl);
  }

  return tooltipEl;
};

const externalTooltipHandler = (context) => {
  // Tooltip Element
  const {
    chart,
    tooltip
  } = context;
  const tooltipEl = getOrCreateTooltip(chart);

  // Hide if no tooltip
  if (tooltip.opacity === 0) {
    tooltipEl.style.opacity = 0;
    return;
  }

  // Set Text
  if (tooltip.body) {
    const titleLines = tooltip.title || [];
    const bodyLines = tooltip.body.map(b => b.lines);

    const tableHead = document.createElement('thead');

    titleLines.forEach(title => {
      const tr = document.createElement('tr');
      tr.style.borderWidth = 0;

      const th = document.createElement('th');
      th.style.borderWidth = 0;
      const text = document.createTextNode(title);
      th.appendChild(text);

			// THIS BLOCK ADDED
      const imageTh = document.createElement('th');
      th.style.borderWidth = 0;
      const image = document.createElement('img');
      image.style = 'width:20px'
      image.src = context.tooltip.dataPoints[0].dataset.url;
      imageTh.appendChild(image);

      tr.appendChild(th);
      tr.appendChild(imageTh);
      tableHead.appendChild(tr);
    });

    const tableBody = document.createElement('tbody');
    bodyLines.forEach((body, i) => {
      const colors = tooltip.labelColors[i];

      const...