# Multi Series Pie
const config = { type: 'pie', data: data, options: { responsive: true, plugins: { legend: { labels: { generateLabels: function(chart) { // Get the default label list const original = Chart.overrides.pie.plugins.legend.labels.generateLabels; const labelsOriginal = original.call(this, chart); // Build an array of colors used in the datasets of the chart let datasetColors = chart.data.datasets.map(function(e) { return e.backgroundColor; }); datasetColors = datasetColors.flat(); // Modify the color and hide state of each label labelsOriginal.forEach(label => { // There are twice as many labels as there are datasets. This converts the label index into the corresponding dataset index label.datasetIndex = (label.index - label.index % 2) / 2; // The hidden state must match the dataset's hidden state label.hidden = !chart.isDatasetVisible(label.datasetIndex); // Change the color to match the dataset label.fillStyle = datasetColors[label.index]; }); return labelsOriginal; } }, onClick: function(mouseEvent, legendItem, legend) { // toggle the visibility of the dataset from what it currently is legend.chart.getDatasetMeta( legendItem.datasetIndex ).hidden = legend.chart.isDatasetVisible(legendItem.datasetIndex); legend.chart.update(); } }, tooltip: { callbacks: { title: function(context) { const labelIndex = (context[0].datasetIndex * 2) + context[0].dataIndex; return context[0].chart.data.labels[labelIndex] + ': ' + context[0].formattedValue; } } } } }, };