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VisualizaçõesHow add the sizes of the slices in the pie chart (at the top) in Chart.js?
I am starting to learn the chart.js library.
I drew a pie chart (like "pie"). When you hover over the slices of the diagram, a number appears in the pop-up window that sets the size of the sector.
new chart(
document.getElementById('diagram_1').getContext('2d'), {
type: 'pie',
data: {
labels: [
'Завершенная задача',
'Новая задача',
'Ошибка выполнения'
],
datasets: [{
label: '# of Votes',
data: [@successful_tasks, @new_tasks, @error_tasks],
backgroundColor: [
'rgba(54, 162, 235, 0.2)',
'rgba(255, 206, 86, 0.2)',
'rgba(255, 99, 132, 0.2)'
],
borderColor: [
'rgba(54, 162, 235, 1)',
'rgba(255, 206, 86, 1)',
'rgba(255, 99, 132, 1)'
],
borderWidth: 1
}]
},
options: {
scales: {
y: {
beginAtZero: true
}
},
responsive: false
}
}
)
How can you make this number still displayed at the top, where the sectors are listed (I marked this place with a red circle in the picture)?
I can add the required number to the labels array
...
data: {
labels: [
'Завершенная задача: ' + @successful_tasks,
'Новая задача: ' + @new_tasks,
'Ошибка выполнения: ' + @error_tasks
],
...
But then this number will appear twice in the tooltip
·
Juan Pablo Isaza
2 Respostas
Responde à pergunta0
You can use the plugin system for this:
var options = {
type: 'pie',
data: {
labels: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"],
datasets: [{
label: '# of Votes',
data: [12, 19, 3, 5, 2, 3],
backgroundColor: ["Red", "Blue", "Yellow", "Green", "Purple", "Orange"]
}]
},
options: {
plugins: {
customNumber: {
textColor: 'red',
xOffset: 10,
yOffset: 0,
font: '24px Comic Sans MS'
}
}
},
plugins: [{
id: 'customNumber',
afterDraw: (chart, args, opts) => {
const hoveredSlice = chart._active[0];
const {
ctx,
chartArea: {
right
}
} = chart;
if (!hoveredSlice) {
return;
}
ctx.font = opts.font || '24px verdana, sans-serif'
ctx.fillStyle = opts.textColor || 'black'
const val = chart.data.datasets[hoveredSlice.datasetIndex].data[hoveredSlice.index];
const meassures = ctx.measureText(val);
const height = ctx.measureText('M').width;
ctx.fillText(val, (right - meassures.width - (opts.xOffset || 0)), height + (opts.yOffset || 0))
}
}]
}
var ctx = document.getElementById('chartJSContainer').getContext('2d');
new Chart(ctx, options);<body>
<canvas id="chartJSContainer" width="600" height="400"></canvas>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/3.6.0/chart.js"></script>
</body>
·
Juan Pablo Isaza
Relatório
0
I found the answer. My project is written in CoffeeScript, but I think it would be more useful for the StackOverflow community to post the code in JS.
options: {
legend: {
labels: {
generateLabels: function(chart) {
var data = chart.data;
if (data.labels.length && data.datasets.length) {
return data.labels.map(function(label, i) {
var meta = chart.getDatasetMeta(0);
var ds = data.datasets[0];
var arc = meta.data[i];
var custom = arc && arc.custom || {};
var getValueAtIndexOrDefault = Chart.helpers.getValueAtIndexOrDefault;
var arcOpts = chart.options.elements.arc;
var fill = custom.backgroundColor ? custom.backgroundColor : getValueAtIndexOrDefault(ds.backgroundColor, i, arcOpts.backgroundColor);
var stroke = custom.borderColor ? custom.borderColor : getValueAtIndexOrDefault(ds.borderColor, i, arcOpts.borderColor);
var bw = custom.borderWidth ? custom.borderWidth : getValueAtIndexOrDefault(ds.borderWidth, i, arcOpts.borderWidth);
var value = chart.config.data.datasets[arc._datasetIndex].data[arc._index];
return {
text: label + ": " + value,
fillStyle: fill,
strokeStyle: stroke,
lineWidth: bw,
hidden: isNaN(ds.data[i]) || meta.data[i].hidden,
index: i
};
});
} else {
return [];
}
}
}
}
}
·
Juan Pablo Isaza
Relatório
Responde à pergunta