@Hung Tran's answer works perfect. As an improvement, I would suggest not showing values that are 0. Say you have 5 elements and 2 of them are 0 and rest of them have values, the solution above will show 0 and 0%. It is better to filter that out with a not equal to 0 check!
var val = dataset.data[i]; var percent = String(Math.round(val/total*100)) + "%"; if(val != 0) { ctx.fillText(dataset.data[i], model.x + x, model.y + y); // Display percent in another line, line break doesn't work for fillText ctx.fillText(percent, model.x + x, model.y + y + 15); }
Updated code below:
var data = {
datasets: [{
data: [
11,
16,
7,
3,
14
],
backgroundColor: [
"#FF6384",
"#4BC0C0",
"#FFCE56",
"#E7E9ED",
"#36A2EB"
],
label: 'My dataset' // for legend
}],
labels: [
"Red",
"Green",
"Yellow",
"Grey",
"Blue"
]
};
var pieOptions = {
events: false,
animation: {
duration: 500,
easing: "easeOutQuart",
onComplete: function () {
var ctx = this.chart.ctx;
ctx.font = Chart.helpers.fontString(Chart.defaults.global.defaultFontFamily, 'normal', Chart.defaults.global.defaultFontFamily);
ctx.textAlign = 'center';
ctx.textBaseline = 'bottom';
this.data.datasets.forEach(function (dataset) {
for (var i = 0; i < dataset.data.length; i++) {
var model = dataset._meta[Object.keys(dataset._meta)[0]].data[i]._model,
total = dataset._meta[Object.keys(dataset._meta)[0]].total,
mid_radius = model.innerRadius + (model.outerRadius - model.innerRadius)/2,
start_angle = model.startAngle,
end_angle = model.endAngle,
mid_angle = start_angle + (end_angle - start_angle)/2;
var x = mid_radius * Math.cos(mid_angle);
var y = mid_radius * Math.sin(mid_angle);
ctx.fillStyle = '#fff';
if (i == 3){ // Darker text color for lighter background
ctx.fillStyle = '#444';
}
var val = dataset.data[i];
var percent = String(Math.round(val/total*100)) + "%";
if(val != 0) {
ctx.fillText(dataset.data[i], model.x + x, model.y + y);
// Display percent in another line, line break doesn't work for fillText
ctx.fillText(percent, model.x + x, model.y + y + 15);
}
}
});
}
}
};
var pieChartCanvas = $("#pieChart");
var pieChart = new Chart(pieChartCanvas, {
type: 'pie', // or doughnut
data: data,
options: pieOptions
});