CODEWITHSUNDEEP
chart.js
Prahlad
Prahlad

Reputation: 796

ChartJs how to get from mulitiple dateset which dataset bar is clicked

I want add a unique url to each bar and open that url on click one of bar. But in my case i have two datasets. I am using onClick event which return active record of both dataset. enter image description here

I am using following code.. It will return both dataset object...it should return only one dataset. 

<script>
        var barChartData = {
            labels: ["Jan","Feb","March"],
            datasets: [{
                label : "Quoted",
                backgroundColor : "#FF7228",
                data : [50,20,70],
            },
            {
                label : "Accepted",
                backgroundColor : "#FFCC8C",
                data :  [30,10,20],
            }, 
            ]

        };

        window.onload = function() {
            var ctx = document.getElementById("canvas").getContext("2d");
            window.myBar = new Chart(ctx, {
                type: 'bar',
                data: barChartData,
                options: {
                    events:['click'],
                    onClick:function(c,i){
                            console.log(this.active);
                            }
                        },
                    responsive: true,
                    legend: {
                        position: 'top',
                    },
                }
            });
        };
 </script>

Upvotes: 8

Views: 5679

Answers (3)

Samuel Liew
Samuel Liew

Reputation: 79022

Updated answer for Chart.js 3.7

Use chart.getElementsAtEventForMode(evt, ...). See documentation.

const barChartData = {
  labels: ["Jan", "Feb", "March"],
  datasets: [{
    label: "Quoted",
    backgroundColor: "#FF7228",
    data: [50, 20, 70],
  }, {
    label: "Accepted",
    backgroundColor: "#FFCC8C",
    data: [30, 10, 20],
  }]
};

const ctx = document.getElementById("canvas").getContext("2d");
const chart = new Chart(ctx, {
  type: 'bar',
  data: barChartData,
  options: {
    onClick: function (evt, elements, chart) {
      const bars = chart.getElementsAtEventForMode(evt, 'nearest', { intersect: true }, true);
      if (bars.length === 0) return; // no bars
      
      const bar = bars[0];
      
      // Get index and label text
      const index = bar.index;
      const label = chart.data.labels[index];
      
      // Get clicked bar dataset index
      const datasetIndex = bar.datasetIndex;
      const isQuotedBar = datasetIndex === 0; // 0 is the first dataset ("Quoted")

      alert(`${isQuotedBar ? 'Quoted' : 'Accepted'} bar was clicked, for ${label}.`);
    }
  },
  responsive: true,
  legend: {
    position: 'top',
  },
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/3.7.1/chart.min.js"></script>
<canvas id="canvas"></canvas>

Upvotes: 3

Jiř&#237; Hern&#237;k
Jiř&#237; Hern&#237;k

Reputation: 2477

Building on Grunt's answer more, if you want to know the underlying data, so consider mine only the onclick code:

var barChartData = {
    labels: ["Jan", "Feb", "March"],
    datasets: [{
        label: "Quoted",
        backgroundColor: "#FF7228",
        data: [50, 20, 70],
    }, {
        label: "Accepted",
        backgroundColor: "#FFCC8C",
        data: [30, 10, 20],
    }]
};

var ctx = document.getElementById("canvas").getContext("2d");
window.myBar = new Chart(ctx, {
    type: 'bar',
    data: barChartData,
    options: {
        onClick: function(e) {
            var bar = this.getElementAtEvent(e)[0];
            if (bar != undefined) {
                var index = bar._index;
                var datasetIndex = bar._datasetIndex;
                alert(barChartData.datasets[datasetIndex].data[index].x +
                    ', ' + barChartData.datasets[datasetIndex].data[index].y);
            }
        }
    },
    responsive: true,
    legend: {
        position: 'top',
    },
});

Upvotes: 1

ɢʀᴜɴᴛ
ɢʀᴜɴᴛ

Reputation: 32859

You can use getElementAtEvent() method to get only one dataset returned. Then you can apply further logic to detect which bar is clicked on.

ᴅᴇᴍᴏ

var barChartData = {
   labels: ["Jan", "Feb", "March"],
   datasets: [{
      label: "Quoted",
      backgroundColor: "#FF7228",
      data: [50, 20, 70],
   }, {
      label: "Accepted",
      backgroundColor: "#FFCC8C",
      data: [30, 10, 20],
   }]
};

var ctx = document.getElementById("canvas").getContext("2d");
window.myBar = new Chart(ctx, {
   type: 'bar',
   data: barChartData,
   options: {
      onClick: function(e) {
         var bar = this.getElementAtEvent(e)[0];
         var index = bar._index;
         var datasetIndex = bar._datasetIndex;

         // check which bar is clicked
         if (index == 0 && datasetIndex == 0) alert('First BAR Clicked!');
         else if (index == 0 && datasetIndex == 1) alert('Second BAR Clicked!');
         else if (index == 1 && datasetIndex == 0) alert('Third BAR Clicked!');
         else if (index == 1 && datasetIndex == 1) alert('Fourth BAR Clicked!');
         else if (index == 2 && datasetIndex == 0) alert('Fifth BAR Clicked!');
         else if (index == 2 && datasetIndex == 1) alert('Sixth BAR Clicked!');
      }
   },
   responsive: true,
   legend: {
      position: 'top',
   },
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.6.0/Chart.min.js"></script>
<canvas id="canvas"></canvas>

Upvotes: 8

Related Questions