Legend and hierarchy series

This tutorial will walk through configuration options for legend content on a hierarchy chart.

Adding legend

To add a legend, we simply need to create an instance of a Legend class (which is a part of “index” package), push it to chart’s children (or any other place we want it to be), as well as set its data (in case of a percent chart, we will probably want to use series data items as legend items).

Since hierarchy charts use tree-like data item structure, we will need to choose what data items to use to feed the legend.

The most common scenario is to use second level data items, that can be accessed via top-level data item’s (which is always one) children setting: series.dataItems[0].get("children").

TypeScript
JavaScript

let legend = chart.children.push(am5.Legend.new(root, {}));
legend.data.setAll(series.dataItems[0].get("children"));

var legend = chart.children.push(am5.Legend.new(root, {}));
legend.data.setAll(series.dataItems[0].get("children"));

Legend label content

Setting content

What goes into legend labels on a percent chart is controlled by four of the series’ settings:

Setting key	Default	Comment
`legendLabelText`	`{category}`	Text for the legend item label.
`legendValueText`	`{value}`	Text for the legend item value label.

To change contents of the legend, we simply need to set corresponding setting value:

TypeScript
JavaScript

let series = chart.series.push(
  am5percent.PieSeries.new(root, {
    name: "Series",
    categoryField: "country",
    valueField: "sales",
    legendLabelText: "{category}",
    legendValueText: "{value}"
  })
);

var series = chart.series.push(
  am5percent.PieSeries.new(root, {
    name: "Series",
    categoryField: "country",
    valueField: "sales",
    legendLabelText: "{category}",
    legendValueText: "{value}"
  })
);

Labels support data placeholders (references to data item settings in curly brackets) so the text will be populated with actual data and values.

Since each legend item is constructed out of the series data items, their data will be used to populate it, e.g. ForceDirectedDataItem.

In-line formatting

Besides regular text and data placeholders, labels support square bracket in-line formatting blocks. E.g.:

TypeScript
JavaScript

let series = chart.series.push(
  am5percent.PieSeries.new(root, {
    name: "Series",
    categoryField: "country",
    valueField: "sales",
    legendLabelText: "[{fill}]{category}[/]",
    legendValueText: "[bold {fill}]{value}[/]"
  })
);

var series = chart.series.push(
  am5percent.PieSeries.new(root, {
    name: "Series",
    categoryField: "country",
    valueField: "sales",
    legendLabelText: "[{fill}]{category}[/]",
    legendValueText: "[bold {fill}]{value}[/]"
  })
);

The above will use slice’s fill (color) for category and value, as well as make category names bold.

Example

Open in CodePen