Chart.js - Doughnut show tooltips always?

Question

When using the Chart.js library, I can add multiple doughnuts on my page without a problem.

http://www.chartjs.org/docs/#doughnut-pie-chart

But I cannot find a way to always show the tooltips - not only when hovering the mouse over the doughnut. Does anybody know if this is possible?

Answer 1

You can do this by writing your own plugin which supports ChartJS version > 2.1.5.

Include the following code in your script:

// Show tooltips always even the stats are zero

Chart.pluginService.register({
  beforeRender: function(chart) {
    if (chart.config.options.showAllTooltips) {
      // create an array of tooltips
      // we can't use the chart tooltip because there is only one tooltip per chart
      chart.pluginTooltips = [];
      chart.config.data.datasets.forEach(function(dataset, i) {
        chart.getDatasetMeta(i).data.forEach(function(sector, j) {
          chart.pluginTooltips.push(new Chart.Tooltip({
            _chart: chart.chart,
            _chartInstance: chart,
            _data: chart.data,
            _options: chart.options.tooltips,
            _active: [sector]
          }, chart));
        });
      });

      // turn off normal tooltips
      chart.options.tooltips.enabled = false;
    }
  },
  afterDraw: function(chart, easing) {
    if (chart.config.options.showAllTooltips) {
      // we don't want the permanent tooltips to animate, so don't do anything till the animation runs atleast once
      if (!chart.allTooltipsOnce) {
        if (easing !== 1)
          return;
        chart.allTooltipsOnce = true;
      }

      // turn on tooltips
      chart.options.tooltips.enabled = true;
      Chart.helpers.each(chart.pluginTooltips, function(tooltip) {
        tooltip.initialize();
        tooltip.update();
        // we don't actually need this since we are not animating tooltips
        tooltip.pivot();
        tooltip.transition(easing).draw();
      });
      chart.options.tooltips.enabled = false;
    }
  }
});

// Show tooltips always even the stats are zero

And then just use the following line in the options of any chart on which you want to show all the tooltips available.

showAllTooltips: true

Working Fiddle is given below

// Show tooltips always even the stats are zero

Chart.pluginService.register({
  beforeRender: function(chart) {
    if (chart.config.options.showAllTooltips) {
      // create an array of tooltips
      // we can't use the chart tooltip because there is only one tooltip per chart
      chart.pluginTooltips = [];
      chart.config.data.datasets.forEach(function(dataset, i) {
        chart.getDatasetMeta(i).data.forEach(function(sector, j) {
          chart.pluginTooltips.push(new Chart.Tooltip({
            _chart: chart.chart,
            _chartInstance: chart,
            _data: chart.data,
            _options: chart.options.tooltips,
            _active: [sector]
          }, chart));
        });
      });

      // turn off normal tooltips
      chart.options.tooltips.enabled = false;
    }
  },
  afterDraw: function(chart, easing) {
    if (chart.config.options.showAllTooltips) {
      // we don't want the permanent tooltips to animate, so don't do anything till the animation runs atleast once
      if (!chart.allTooltipsOnce) {
        if (easing !== 1)
          return;
        chart.allTooltipsOnce = true;
      }

      // turn on tooltips
      chart.options.tooltips.enabled = true;
      Chart.helpers.each(chart.pluginTooltips, function(tooltip) {
        tooltip.initialize();
        tooltip.update();
        // we don't actually need this since we are not animating tooltips
        tooltip.pivot();
        tooltip.transition(easing).draw();
      });
      chart.options.tooltips.enabled = false;
    }
  }
});

// Show tooltips always even the stats are zero


var canvas = $('#myCanvas2').get(0).getContext('2d');
var doughnutChart = new Chart(canvas, {
  type: 'doughnut',
  data: {
    labels: [
      "Success",
      "Failure"
    ],
    datasets: [{
      data: [45, 9],
      backgroundColor: [
        "#1ABC9C",
        "#566573"
      ],
      hoverBackgroundColor: [
        "#148F77",
        "#273746"
      ]
    }]
  },
  options: {
    // In options, just use the following line to show all the tooltips
    showAllTooltips: true
  }
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.3.0/Chart.bundle.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<div>
     <canvas id="myCanvas2" width="350" height="296"></canvas>
</div>

Working JSFIDDLE here.

Answer 2

In case someone tries to hide some of the segment tooltips; do it in the tooltipTemplate:

tooltipTemplate : "<%  var percentage = Math.round(circumference / 6.283 * 100); if (percentage >8)%><%= percentage %>%";

for example this code checks for the %value and only displays values higher than 8% to decrease clutter

Answer 3

If you want to display just ONE tooltip, you have to use this code. Here is exaple for first segment.

chart.showTooltip([chart.segments[0]], true);

Function showTooltip only accepts 2 dimensional arrays for first parameter.

Answer 4

I expanded on Kapi's method so when you hover over it you still get to keep the default functionality like color change, and when you hover over a section it will hide the rest. I think it looks better.

var options =
{
    onAnimationComplete: function () {
        this.showTooltip(this.segments, true);
    },        
}

var ctx = document.getElementById("Chart").getContext("2d");
var myPieChart = new Chart(ctx).Pie(data, options);

$("#Chart").on('mouseleave', function (){
    myPieChart.showTooltip(myPieChart.segments, true);
});

Answer 5

I had the same problem today and solved it quite easy by adding the options onAnimationComplte and tooltipevents.

onAnitmationComplete calls the method to show the tooltips like a hover event does. Normally you define the events in tooltipevents to display the tooltips but we need to remove them and pass an empty array.

Note:(http://www.chartjs.org/docs/#doughnut-pie-chart).

Javascript:

var options = 
{
    tooltipTemplate: "<%= value %>",

    onAnimationComplete: function()
    {
        this.showTooltip(this.segments, true);

        //Show tooltips in bar chart (issue: multiple datasets doesnt work http://jsfiddle.net/5gyfykka/14/)
        //this.showTooltip(this.datasets[0].bars, true);

        //Show tooltips in line chart (issue: multiple datasets doesnt work http://jsfiddle.net/5gyfykka/14/)
        //this.showTooltip(this.datasets[0].points, true);  
    },

    tooltipEvents: [],

    showTooltips: true
}

var context = $('#chart').get(0).getContext('2d');
var chart = new Chart(context).Pie(data, options);  

HTML:

<div id="chartContainer">
    <canvas id="chart" width="200" height="200"></canvas>
</div>

Example Data:

var data = [
    {
        value: 300,
        color:"#F7464A",
        highlight: "#FF5A5E"
    },
    {
        value: 50,
        color: "#46BFBD",
        highlight: "#5AD3D1"
    },
    {
        value: 100,
        color: "#FDB45C",
        highlight: "#FFC870"
    }
]

JSFiddle PIE: http://jsfiddle.net/5gyfykka/

JSFiddle BAR/LINE: http://jsfiddle.net/5gyfykka/14/