I've been working on updating a live chart every 5 seconds with new data from the database. While I could easily update the information, I encountered a problem when trying to set a path within the chart options for tooltips callbacks afterTitle. Specifically, I need to access an array inside this callback function and pass data from the JSON response into it.

To achieve this, I already have a function that updates the data and labels successfully. Now, within this function, I need to create a path to afterTitle so that I can include the fifth array containing the required data. Despite being able to update the data and labels in the function, I'm facing challenges in incorporating another array without causing the chart to blink with each update.

Below is the example code snippet where I tried to incorporate the necessary changes:

$.getJSON('loadchart.php', function(response) {
          myLineChart.data.datasets[0].data = response[0];
          myLineChart.data.datasets[1].data = response[1];
          myLineChart.data.datasets[2].data = response[2];
          myLineChart.data.datasets[3].data = response[3];
          myLineChart.data.labels = response[4];

          //The response array that I need is response[5];
          //myLineChart.options.tooltips.callbacks[1] = return response[tooltipItem[0]['index']]; 
          myLineChart.update();
        });

Here's an overview of my Chart structure including the defined path:

 <script>

    function loadData() {
      $.getJSON('loadchart.php', function(response) {
        myLineChart.data.datasets[0].data = response[0];
        myLineChart.data.datasets[1].data = response[1];
        myLineChart.data.datasets[2].data = response[2];
        myLineChart.data.datasets[3].data = response[3];
        myLineChart.data.labels = response[4];

        myLineChart.update();
      });
    }

    loadData();
    setInterval(loadData, 5000);

    var lbl = [];
    var ctx1 = document.getElementById('mychart1').getContext('2d');

    var myLineChart = new Chart(ctx1, {
        type: 'line', 
        data: {
          labels: lbl,
          datasets: [
            {
              label: "Current 1",
              data: [],
              borderWidht: 6,
              borderColor: 'red',
              backgroundColor: 'transparent'
            },
            {
              label: "Current 2",
              data: [],
              borderWidht: 6,
              borderColor: 'blue',
              backgroundColor: 'transparent'
            },
            {
              label: "Current 3",
              data: [],
              borderWidht: 6,
              borderColor: 'green',
              backgroundColor: 'transparent'
            },
            {
              label: "Total Current",
              data: [],
              borderWidht: 6,
              borderColor: 'black',
              backgroundColor: 'transparent'
            },
          ]            
        },
        options: {
          animation:{
            update: 0
          },
          scales: {
            yAxes: [{
              ticks: {
                beginAtZero: true
              }
            }],
            xAxes: [{
              gridLines: {
                display: false
              }
            }]
          },

          title: {
            display: true,
            fontSize: 20,
            text: "Current Graph"
          },

          labels: {
            fontStyle: "bold",
          },

          layout: {
            padding: {
              left: 0,
              right: 0,
              top: 0,
              bottom: 0
            }
          },
          tooltips: {
            enabled: true,
            mode: 'single',
            responsive: true,
            backgroundColor: 'black',
            titleFontFamily: "'Arial'",
            titleFontSize: 14,
            titleFontStyle: 'bold',
            titleAlign: 'center',
            titleSpacing: 4,
            titleMarginBottom: 10,
            bodyFontFamily: "'Mukta'",
            bodyFontSize: 14,
            borderWidth: 2,
            borderColor: 'grey',
            callbacks:{
              title: function(tooltipItem, data) {
                  return data.labels[tooltipItem[0].index];
              },
              afterTitle: function(tooltipItem, data) {
                var tempo = [];
                return tempo[tooltipItem[0]['index']];
              },
              label: function(tooltipItem, data) {
                    var label = data.datasets[tooltipItem.datasetIndex].label || '';                  
                    if (label) {
                        label += ': ';
                    }
                    label += (tooltipItem.yLabel)+"A";                  
                    return label;
              }
            }
          },
          aspectRatio: 1,
          maintainAspectRatio: false
        }
    });
</script>

The specific part requiring modification is shown here:

afterTitle: function(tooltipItem, data) {
                var tempo = [];
                return tempo[tooltipItem[0]['index']];