How do I prevent Chartjs tooltip callback returning multiple instances of the same value?

Question

I am using Chartjs with React. I have a cryptocurrency price chart with three datasets with one being a list of prices, one being a horizontal line that is tangent to the initial price and another horizontal line that is a tangent of the highest point. Here they are:

datasets: [
        {
          label: 'pricesData',
          fill: false,
          lineTension: 0,
          backgroundColor: 'rgba(75,192,192,1)',
          borderColor: chartColor,
          borderWidth: 2,
          data: prices
        },
        {
          
          label: '0 line',
          radius: 0,
          fill: false,
          borderDash: [10,5],
          data: zeroLine,
          backgroundColor: 'rgba(255,255,255,1)',
          borderColor: 'rgba(255, 255, 255,.5)',
      
      
        },
        {
          label: 'top Line',
          radius: 0,
          fill: false,
          borderDash: [10,5],
          data: topLine,
          borderColor: 'rgba(255, 255, 255,0)'
        }

I am trying to create a feature that changes the displayed price in another component based on where you are on the graph. Here is the callback function in the label option:

callbacks: {
                label: function(tooltipItem, data) {
                    var item = data.datasets[0].data[tooltipItem.index];
                    var zeroLine = data.datasets[1].data[tooltipItem.index]
                    let properties = {
                        price: item,
                        percentChange: (((item-zeroLine)/zeroLine)*100).toFixed(2) 
                    }
                    props.parentCallback(properties);
                    return(item)
                }
            }

Now this works like expected except it runs three times and the returned item fills the tooltip with three instances. I imagine this is because I have three datasets. How would I prevent this and only call the props callback once and fill the tooltip with only one value? There is also a slight framerate hitch that I imagine is caused by this.

Answer 1

I have answered my own question. For anyone with a similar issue you can configure your tooltip with this option so that it will only use one dataset:

tooltips: {
filter: function (tooltipItem) {
    return tooltipItem.datasetIndex === 0;
}
}