Hybrid Drill-Down Pie/Bar Chart

// Set up data
var data = [{
  category: "Critical",
  value: 89,
  breakdown: [{
    category: "Sales inquiries",
    value: 29
  }, {
    category: "Support requests",
    value: 40
  }, {
    category: "Bug reports",
    value: 11
  }, {
    category: "Other",
    value: 9
  }]
}, {
  category: "Acceptable",
  value: 71,
  breakdown: [{
    category: "Sales inquiries",
    value: 22
  }, {
    category: "Support requests",
    value: 30
  }, {
    category: "Bug reports",
    value: 11
  }, {
    category: "Other",
    value: 10
  }]
}, {
  category: "Good",
  value: 120,
  breakdown: [{
    category: "Sales inquiries",
    value: 60
  }, {
    category: "Support requests",
    value: 35
  }, {
    category: "Bug reports",
    value: 15
  }, {
    category: "Other",
    value: 10
  }]
}]

// Create root element
// https://docs.amcharts.com/v5/getting-started/#root-element
var root = am5.Root.new("chartdiv");

// Set themes
// https://docs.amcharts.com/v5/concepts/themes/
var responsive = am5themes_Responsive.new(root);
root.setThemes([
  am5themes_Animated.new(root),
  responsive
]);

// On a chart 400px wide or narrower, the bar chart's category names stand upright, reading
// up along their bars, so the bars get the width
responsive.addRule({
  name: "AxisLabel",
  tags: ["y"],
  relevant: am5themes_Responsive.widthM,
  settings: {
    rotation: -90,
    centerX: am5.p50,  // centered on the row...
    centerY: am5.p100, // ...beside the axis
    paddingBottom: 6   // turned upright, the bottom padding is the gap to the axis
  }
});

// Create wrapper container
var container = root.container.children.push(am5.Container.new(root, {
  width: am5.p100,              // fills the whole chart area
  height: am5.p100,
  layout: root.horizontalLayout // the bar chart and the donut side by side
}));

// ==============================================
// Column chart
// ==============================================

// Create chart
// https://docs.amcharts.com/v5/charts/xy-chart/
var columnChart = container.children.push(am5xy.XYChart.new(root, {
  width: am5.p50, // half the width
  panX: false,    // no dragging the plot
  panY: false,
  wheelX: "none", // the mouse wheel scrolls the page, not the chart
  wheelY: "none",
  layout: root.verticalLayout
}));

// Create axes
// https://docs.amcharts.com/v5/charts/xy-chart/axes/
var yRenderer = am5xy.AxisRendererY.new(root, {});
var yAxis = columnChart.yAxes.push(am5xy.CategoryAxis.new(root, {
  categoryField: "category",
  renderer: yRenderer
}));

yRenderer.grid.template.setAll({
  location: 1 // grid lines at the end of each row, between the bars
})

var xAxis = columnChart.xAxes.push(am5xy.ValueAxis.new(root, {
  renderer: am5xy.AxisRendererX.new(root, {
    strokeOpacity: 0.1 // a faint axis line
  })
}));

// Add series
// https://docs.amcharts.com/v5/charts/xy-chart/series/
var columnSeries = columnChart.series.push(am5xy.ColumnSeries.new(root, {
  xAxis: xAxis,
  yAxis: yAxis,
  valueXField: "value",
  categoryYField: "category"
}));

columnSeries.columns.template.setAll({
  tooltipText: "{categoryY}: {valueX}" // as "Support requests: 40"
});


// Make stuff animate on load
// https://docs.amcharts.com/v5/concepts/animations/
columnChart.appear(1000, 100);

// ==============================================
// Pie chart
// ==============================================

var pieChart = container.children.push(
  am5percent.PieChart.new(root, {
    width: am5.p50,              // the other half
    innerRadius: am5.percent(50) // a hole half the radius turns the pie into a donut
  })
);

// Create series
var pieSeries = pieChart.series.push(
  am5percent.PieSeries.new(root, {
    valueField: "value",
    categoryField: "category"
  })
);

pieSeries.slices.template.setAll({
  // each slice's color comes from sliceSettings in its data
  templateField: "sliceSettings",
  strokeOpacity: 0 // no outline
});

// Clicking a slice selects it and shows its breakdown in the bar chart. One slice stays selected: clicking the
// selected slice again does not deselect it
var currentSlice;
pieSeries.slices.template.on("active", function(active, slice) {
  if (!active) {
    if (slice == currentSlice) {
      slice.set("active", true);
    }
    return;
  }

  var previousSlice = currentSlice;
  currentSlice = slice;
  if (previousSlice && previousSlice != slice) {
    previousSlice.set("active", false);
  }

  var color = slice.get("fill");

  label1.setAll({
    fill: color,
    text: root.numberFormatter.format(slice.dataItem.get("valuePercentTotal"), "#.'%'") // as "32%"
  });

  label2.set("text", slice.dataItem.get("category"));

  // the bars take the slice's color
  columnSeries.columns.template.setAll({
    fill: slice.get("fill"),
    stroke: slice.get("fill")
  });

  columnSeries.data.setAll(slice.dataItem.dataContext.breakdown);
  yAxis.data.setAll(slice.dataItem.dataContext.breakdown);
});

pieSeries.labels.template.set("forceHidden", true); // no labels around the donut...
pieSeries.ticks.template.set("forceHidden", true);  // ...and no ticks

// Each slice's color, by how good it is: the theme's color for negative values (red) for Critical, its warning color
// (yellow) for Acceptable and its positive one (green) for Good, so they follow the theme and dark mode
var goodness = { Critical: "negative", Acceptable: "warning", Good: "positive" };
data.forEach(function(item) {
  item.sliceSettings = {
    fill: root.interfaceColors.get(goodness[item.category])
  };
});

pieSeries.data.setAll(data);

// Add label
var label1 = pieChart.seriesContainer.children.push(am5.Label.new(root, {
  text: "",           // filled in when a slice is selected
  fontSize: 35,       // big...
  fontWeight: "bold", // ...bold text...
  centerX: am5.p50,   // ...centered in the hole
  centerY: am5.p50
}));

var label2 = pieChart.seriesContainer.children.push(am5.Label.new(root, {
  text: "",
  fontSize: 12,     // small text...
  centerX: am5.p50, // ...centered too
  centerY: am5.p50,
  // the category name, under the percentage in the donut's hole
  dy: 30
}));

// Pre-select first slice
pieSeries.events.on("datavalidated", function() {
  pieSeries.slices.getIndex(0).set("active", true);
});